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Table of contents

Papers

P08068

, , , , , , , , , et al

Charged-current neutrino interactions with low hadronic recoil ("low-ν") have a cross-section that is approximately constant versus neutrino energy. These interactions have been used to measure the shape of neutrino fluxes as a function of neutrino energy at accelerator-based neutrino experiments such as CCFR, NuTeV, MINOS and MINERνA. In this paper, we demonstrate that low-ν events can be used to measure parameters of neutrino flux and detector models and that utilization of event distributions over the upstream detector face can discriminate among parameters that affect the neutrino flux model. From fitting a large sample of low-ν events obtained by exposing MINERνA to the NuMI medium-energy beam, we find that the best-fit flux parameters are within their a priori uncertainties, but the energy scale of muons reconstructed in the MINOS detector is shifted by 3.6% (or 1.8 times the a priori uncertainty on that parameter). These fit results are now used in all MINERνA cross-section measurements, and this technique can be applied by other experiments operating at MINERνA energies, such as DUNE.

P08067

, , , , , , , , , et al

NaI(Tl+Li) (NaIL) is a promising new inorganic scintillator for thermal neutron detection with the ability for pulse shape discrimination (PSD). In this study, we first built a dual-gamma/neutron sensitive detector based on a NaIL scintillator, a photomultiplier tube and a custom-built circuit. Then, we investigated its temperature response and optimized the PSD parameters, obtaining a figure of merit (FOM) of up to 4.5 at 0–50°C. Also, we examined the effect of the count rate on the detector's neutron and gamma discrimination performance; after optimization, we obtained an FOM of above 3.0 at 5000–40000 counts per second. Lastly, we estimated the neutron detection efficiency of this detector, which is about 13 cps/nv. This detector gave an excellent performance in neutron/gamma discrimination, and can be used widely in the detection of mixed radiation fields.

P08066

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Despite being thought as a kind of near-ideal light signal amplifier, photomultiplier tubes actually will add an additional contribution to the output signal of scintillation detectors when being irradiated. The contribution is rather small for those detectors consisted of various high-yield scintillators and is thought for a long time to not produce any adverse impact. In the paper, through simulation analysis and well-designed reversed experiment, it is demonstrated that not only being widely accepted Cherenkov emission but also fluorescence emission in the input window both plays great role in the additional contribution. Furthermore, it is also verified through experiments that the radiation conversion performance of this contribution is different or even lower than that of common inorganic scintillators. This leads that the merits of low-yield scintillators are lost in coaxial detector and some measurement results corrected based on the standard performance of the scintillators are usually incorrect. To reduce the adverse impact and acquire the requested performance of some new low-yield scintillators, a kind of off-axis detector layout is designed and proved to be effective.

P08065

, , , , , , , , , et al

An innovative Cylindrical Gas Electron Multiplier (CGEM) detector is under construction for the upgrade of the inner tracker of the BESIII experiment. A novel system has been worked out for the readout of the CGEM detector, including a new ASIC, dubbed TIGER -Torino Integrated GEM Electronics for Readout, designed for the amplification and digitization of the CGEM output signals. The data output by TIGER are collected and processed by a first FPGA-based module, GEM Read Out Card, in charge of configuration and control of the front-end ASICs. A second FPGA-based module, named GEM Data Concentrator, builds the trigger selected event packets containing the data and stores them via the main BESIII data acquisition system. The design of the electronics chain, including the power and signal distribution, will be presented together with its performance.

P08064

, , , , , and

Low-energy X-ray imaging of prompt secondary electron bremsstrahlung X-rays (prompt X-rays) emitted during particle-ion irradiation is a promising method for range estimation. However, measurements have so far been conducted mainly for uniform phantoms of water or an acrylic block. Prompt X-ray imaging for phantoms with air cavities has not yet been extensively measured or evaluated with realistic conditions. Consequently, we conducted imaging of prompt X-rays using a pinhole YAP(Ce) camera during irradiation by protons as well as carbon ions to non-uniform acrylic phantoms with small cavities and then evaluated the images and estimated the ranges from the measured prompt X-ray images. The non-uniform acrylic phantom used for imaging had a cylindrical cavity with a 20-mm or 10-mm diameter in the phantom. During irradiation by protons or carbon ions, imaging of one of the phantoms was conducted using the pinhole YAP(Ce) camera with an air cavity as well as filling the cavity with an acrylic rod. For the phantom with a 20-mm-diameter cavity, the prompt X-ray images measured for both protons and carbon ions showed the shape of the cavity in the images, and the ranges could be estimated from the images. For the phantom with a 10-mm-diameter hole, although the shape of the hole could not be clearly observed, the ranges could also be estimated from the images. Furthermore, Monte Carlo simulated prompt X-ray images with different spatial resolution of the X-ray camera showed similar images to the measured images. We confirmed that prompt X-ray imaging of phantoms with air cavities using the pinhole YAP(Ce) cameras was possible and that prompt X-ray imaging is a promising approach for estimating the ranges for both protons and carbon ions, even for phantoms with air cavities.

P08063
The following article is Open access

, , , , , , , , , et al

We report the results of the analyses of the cosmic ray data collected with a 4 tonne (3×1×1 m3) active mass (volume) Liquid Argon Time-Projection Chamber (TPC) operated in a dual-phase mode. We present a detailed study of the TPC's response, its main detector parameters and performance. The results are important for the understanding and further developments of the dual-phase technology, thanks to the verification of key aspects, such as the extraction of electrons from liquid to gas and their amplification through the entire one square metre readout plain, gain stability, purity and charge sharing between readout views.

P08062

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Although optical imaging of decayed positrons and muons can provide promising methods, it has been attempted only for muons without a collimator, and the beam characteristics with collimators, such as peak position or beam spread in depth and lateral directions, have not yet been evaluated. Therefore, we conducted optical imaging of decayed positrons and muons with different collimators. For the imaging of decayed positrons, Cherenkov-light imaging in fluorescein (FS) water was used, while imaging of a plastic scintillator block was used for the imaging of muons. We conducted these imaging trials during irradiation with 84.5-MeV/c positive muons to an FS water phantom or a plastic scintillator block using a cooled charge-coupled device (CCD) camera with each collimator of a different diameter attached to the beam port. We could measure the Cherenkov-light images of FS water of decayed positrons and optical images of muons using the plastic scintillator block for all collimators. The depth profiles of the Cherenkov-light images were slightly wider for the muons with the collimators of larger diameters, although the estimated peak depths were nearly the same for all collimators. The lateral profiles of the Cherenkov light were wider for the muons when using collimators of larger diameters. Asymmetry in the directions of positron emissions from the muons was observed for all collimators. The depth profiles of the optical image of muons using a plastic scintillator block had nearly the same shape. The estimated lateral widths of the optical images of the plastic scintillator block were the same sizes as the collimator diameters within a 1.1-mm difference at a 10-mm depth of the scintillator block, and the widths were wider at the Bragg peak. With these measured optical images, we conclude that Cherenkov-light imaging of decayed positrons in water and optical imaging of muons using a plastic scintillator block with collimators are useful methods for determining not only peak position but also beam width as well as the asymmetry of the directions of positron emissions from the muons.

P08061

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The Isotope Decay-At-Rest experiment (IsoDAR) is a proposed underground experiment which is expected to be a definitive search for sterile neutrinos. In order to be decisive within 5 years, high rates of neutrinos must be produced, by impinging a 10 mA continuous wave proton beam at 60 MeV on a high power target. Due to space restrictions, a compact cyclotron was chosen as an accelerator to produce this driver beam. To overcome space charge limitations during injection, H2+ ions are accelerated and later stripped into protons by means of a carbon foil. IsoDAR uses an especially designed low-frequency (32.8 MHz) split-coaxial Radio-Frequency Quadrupole (RFQ) to effectively bunch H2+ ions before injecting them into this cyclotron. The RFQ will be embedded vertically in the cyclotron yoke, facilitating a very compact design. This puts stringent limits on RFQ size, type, and accessibility. Here, we present the design and optimization of the low-frequency (32.8 MHz) RF input-coupler for the IsoDAR RFQ. The design is challenging due to the necessarily small diameter of the RFQ (28 cm) and the split-coaxial type, as well as limited access to the RFQ. We have determined the optimal position and shape for the coupler, leading to a low power consumption of < 6 kW for an inter-vane voltage of 22 kV. The highest calculated fields are safely below the Kilpatrick limit for this structure.

P08060

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Spectrometry in radiation fields generated by high power lasers is challenging, since the radiation is created in ultra short pulses (10-14–10-12 s) and thus standard spectrometric methods cannot be applied. The electromagnetic calorimeter developed within this study is an active system that can be used for such spectrometry in the energy range from tens of keV to tens of MeV; even for high repetition rate petawatt class laser systems (10 Hz). The calorimeter comprises of a set of scintillators that are wrapped in PTFE and placed into a 3D printed holder. Scintillation light is detected by a CMOS camera, the acquired dose-depth curve is then evaluated by a dedicated unfolding algorithm. In this paper, the calibration of the calorimeter using Cs-137 and Co-60 radioactive sources is presented. The results demonstrate the developed calorimeter is able to determine energy of impinging radiation with an uncertainty of approximately 10%.

P08059

, , , , , , , , , et al

The SNO+ experiment is located 2 km underground at SNOLAB in Sudbury, Canada. A low background search for neutrinoless double beta (0νββ) decay will be conducted using 780 tonnes of liquid scintillator loaded with 3.9 tonnes of natural tellurium, corresponding to 1.3 tonnes of 130Te. This paper provides a general overview of the SNO+ experiment, including detector design, construction of process plants, commissioning efforts, electronics upgrades, data acquisition systems, and calibration techniques. The SNO+ collaboration is reusing the acrylic vessel, PMT array, and electronics of the SNO detector, having made a number of experimental upgrades and essential adaptations for use with the liquid scintillator. With low backgrounds and a low energy threshold, the SNO+ collaboration will also pursue a rich physics program beyond the search for 0νββ decay, including studies of geo- and reactor antineutrinos, supernova and solar neutrinos, and exotic physics such as the search for invisible nucleon decay. The SNO+ approach to the search for 0νββ decay is scalable: a future phase with high 130Te-loading is envisioned to probe an effective Majorana mass in the inverted mass ordering region.

P08058

, , , , and

Neutrons have been widely used, such as neutron imaging, transmutation of nuclear waste, Neutron Capture Therapy (NCT), et al. Neutrons are generally produced by nuclear reactors or accelerator-driven neutron sources. Comparing with nuclear reactors, accelerator-driven neutron sources have many advantages, such as compact and cheap. We proposed a coupled RFQ-DTL cavity as the main component of a miniaturized neutron source. A high accelerating efficiency was achieved by placing Radio Frequency Quadrupole (RFQ) and Drift Tube Linac (DTL) in one cavity. Since the fringe field will increase the energy spread, we propose a method using the fringe field as a buncher to reduce the negative effect, and it will eliminate the use of external bunchers. The coupled RFQ-DTL cavity will accelerator a 25 mA proton beam from 35 keV to 2.5 MeV within 2.23 m. RFQ section and DTL section are 1.55 m and 0.68 m, respectively. Compared with a conventional RFQ, the length of coupled RFQ-DTL is shorten by 53%. The total transmission efficiency is 98.55%. A variable energy design for the beam output energy can be achieved by changing the insertion depth of the DTL tuner and controlling the feeding power of the cavity.

P08057

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The IceCube-Gen2 Neutrino Observatory will feature an in-ice optical array, a larger in-ice radio detector array, and a surface cosmic-ray air-shower array. The surface array will consist of stations based on the experience from the planned IceTop enhancement, each station having four pairs of scintillator panels, three radio antennas and a central hub hosting electronics for data readout and time digitization. In the currently proposed implementation, a surface station will be located in the proximity of each of the 120 in-ice optical strings. Together with the in-ice optical array, the designed array will help to test hadronic interaction models and will extend IceTop's measurement of the energy spectrum and mass composition beyond 10 PeV. The array will also serve as a background veto for down-going candidate neutrino events. In addition, the surface stations will be fundamental to characterize the atmospheric component of the in-ice spectrum (i.e. atmospheric neutrinos and muons) and may serve as a cross calibration tool for the in-ice radio array. In this presentation the physics motivations for the surface array, and the proposed implementation plan will be reviewed.

P08056

In the readout of silicon photomultipliers (SiPMs), the original current signals are usually divided into different channels — fast timing channels, slow energy channels, position encoding channels, facilitating the formation of different trigger types. This paper proposes a modified dynamic time over threshold (DTOT) method to obtain the energy information in the slow energy channel using the fast timing trigger of a 6 mm SiPM coupled to a 10 mm cubic GAGG scintillator. The dynamic threshold generator is triggered by a fast timing signal instead of the energy signal itself. The feasibility of this method was verified using a prototype circuit, wherein the integral nonlinearity was measured to be 1.5%. This method can easily introduce external triggers to the DTOT system, such as a coincident signal with a specific trigger logic, which can extend the application of the DTOT method.

P08055

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In this work the concept of a novel slow neutron collimator and the way to operate it are presented. The idea is based on the possibility to decouple the device's field-of-view from its collimation power. A multi-channel geometry is proposed consisting of a chess-board structure where highly neutron-absorbing channels are alternated to air channels. A borated polymer was purposely developed to produce the attenuating components in the form of square-sectioned long rods. A scalable structure consisting of multiple collimation sectors can be arranged. The geometrical parameter L/D, corresponding to the ratio between the length of a channel and its width, defines the collimation power. Several sectors can be arranged one after the other to reach relevant collimation powers. Each sector, 100 mm long, is composed by several channels with D = 2.5 mm corresponding to an L/D coefficient of 40. The target field of view is 50×50 mm2. This novel collimator, developed inside the INFN-ANET collaboration, due to its intrinsic compactness, will be of great importance to enhance the neutron imaging capability of small to medium-size neutron sources.

P08054

, , , , , , and

INTPIX4NA is an integration-type silicon-on-insulator pixel detector. This detector has a 14.1 × 8.7 mm2 sensitive area, 425,984 (832 column × 512 row matrix) pixels and the pixel size is 17 × 17 μm2. This detector was developed for residual stress measurement using X-rays (the cos α method). The performance of INTPIX4NA was tested with the synchrotron beamlines of the Photon Factory (KEK), and the following results were obtained. The modulation transfer function, the index of the spatial resolution, was more than 50% at the Nyquist frequency (29.4 cycle/mm). The energy resolution analyzed from the collected charge counts is 35.3%–46.2% at 5.415 keV, 21.7%–35.6% at 8 keV, and 15.7%–19.4% at 12 keV. The X-ray signal can be separated from the noise even at a low energy of 5.415 keV at room temperature (approximately 25–27 °C). The maximum frame rate at which the signal quality can be maintained is 153 fps in the current measurement system. These results satisfy the required performance in the air and at room temperature (approximately 25–27 °C) condition that is assumed for the environment of the residual stress measurement.

P08053

, , , , , , , , , et al

The performances of Low Gain Avalanche Diode (LGAD) sensors from a neutron irradiation campaign with fluences of 0.8 × 1015, 1.5 × 1015 and 2.5 × 1015neq/cm2 are reported in this article. These LGAD sensors are developed by the Institute of High Energy Physics, Chinese Academy of Sciences and the Novel Device Laboratory for the High Granularity Timing Detector of the High Luminosity Large Hadron Collider. The timing resolution and collected charge of the LGAD sensors were measured with electrons from a beta source. After irradiation with a fluence of 2.5 × 1015neq/cm2, the collected charge decreases from 40 fC to 7 fC, the signal-to-noise ratio deteriorates from 48 to 12, and the timing resolution increases from 29 ps to 39 ps.

P08052
The following article is Open access

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The DARWIN observatory is a proposed next-generation experiment to search for particle dark matter and other rare interactions. It will operate a 50 t liquid xenon detector, with 40 t in the time projection chamber (TPC). To inform the final detector design and technical choices, a series of technological questions must first be addressed. Here we describe a full-scale demonstrator in the vertical dimension, Xenoscope, with the main goal of achieving electron drift over a 2.6 m distance, which is the scale of the DARWIN TPC. We have designed and constructed the facility infrastructure, including the cryostat, cryogenic and purification systems, the xenon storage and recuperation system, as well as the slow control system. We have also designed a xenon purity monitor and the TPC, with the fabrication of the former nearly complete. In a first commissioning run of the facility without an inner detector, we demonstrated the nominal operational reach of Xenoscope and benchmarked the components of the cryogenic and slow control systems, demonstrating reliable and continuous operation of all subsystems over 40 days. The infrastructure is thus ready for the integration of the purity monitor, followed by the TPC. Further applications of the facility include R&D on the high voltage feedthrough for DARWIN, measurements of electron cloud diffusion, as well as measurements of optical properties of liquid xenon. In the future, Xenoscope will be available as a test platform for the DARWIN collaboration to characterise new detector technologies.

P08051

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A compact, 96-ch, multi-functional and practical front-end readout electronics system for a SiPM based PET detector is developed. This electronics system is based on the latest Sigma Delta Modulation (SDM) circuit, which implements a charge-to-digital conversion (QDC) that keeps energy, timing information. In order to achieve a compact size, the system has a stacked structure including two kinds of boards, analog board and digital board. The analog board is responsible for charge integration of SDM while the digital board is for discharging feedback of the SDM circuit. Also, the digital board is applied for energy calculation, timing pickoff and data buffering and transferring. In comparison to the initial version of the SDM QDC, the input signal polarity on the electronics system is improved from negative only to both positive and negative polarities so that it can process both SiPM anode and cathode signals. Several SiPM based PET detectors are applied to validate the capability of dual polarity readout and multi-functionality. Overall, the prototype electronics system demonstrated its good performance for PET application.

P08050
The following article is Open access

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The design of detectors used for experiments in high-energy physics requires a light, stiff, and efficient cooling system with a low material budget. The use of silicon microchannel cooling plates has gained considerable interest in the last decade. In this study, we propose the development of silicon microchannel cooling frames studied within the framework of the major upgrade of the Inner Tracking System (ITS) of the ALICE experiment at CERN. The preliminary results obtained with these frames demonstrate that they can withstand the internal pressure arising from the flow of the coolant with a limited mass penalty.

P08049

, , , and

Rationale and Objectives: the use of zebrafish (Danio rerio) as an animal model in scientific studies has increased due to its many advantages for research. The multimodal micro PET/SPECT/CT equipment was developed for preclinical studies that use hybrid images of small rodents. It is not clear in the literature whether this type of equipment can be used for studies of smaller animals. We evaluated the feasibility of using the CT modality of a multimodal PET/SPECT/CT equipment for preclinical studies with zebrafish. Materials and Methods: since the CT modality of the equipment is optimized for imaging of small rodents, structural changes were tested to adapt it to the use of zebrafish: alteration of the additional aluminum filter of the X-ray tube and use of an adapted stretcher of high density extended polystyrene (EPS). The appearance of artifacts, changes in spatial resolution, contrast and image uniformity were evaluated using phantoms. Results: the images were visually analyzed to verify which anatomical structures can be identified after the system adjustments. The best results were obtained with a 0.2 mm thick aluminum filter and the adapted EPS stretcher, for both the phantom and animal images. It was possible to identify diverse structures such as swimming bladders, digestive tract and bone structures. Conclusion: using the proposed adaptations, the CT modality of a multimodal PET/SPECT/CT equipment can be utilized to carry out preclinical studies with zebrafish as the animal model.

P08048

, , , , , , , , , et al

We report on the technical design and expected performance of a 592 kg heavy-water-Cherenkov detector to measure the absolute neutrino flux from the pion-decay-at-rest neutrino source at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL). The detector will be located roughly 20 m from the SNS target and will measure the neutrino flux with better than 5% statistical uncertainty in 2 years. This heavy-water detector will serve as the first module of a two-module detector system to ultimately measure the neutrino flux to 2–3% at both the First Target Station and the planned Second Target Station of the SNS. This detector will significantly reduce a dominant systematic uncertainty for neutrino cross-section measurements at the SNS, increasing the sensitivity of searches for new physics.

P08047
The following article is Open access

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Channelization is one of the most important parts in a Digital Back-End(DBE) for radio astronomy. A DBE with wider bandwidth and higher resolution consumes larger amount of computing and memory resources, which results in much higher hardware cost. This paper presents an efficient channelization architecture, which consists of Bit-Inverted, Parallel Complex Fast Fourier Transform(BIPC-FFT) and In-place Forward-Backward Decomposition(IPFBD). The efficient architecture can assist with saving a lot of resources, so a wide-band and high-resolution DBE can be implemented on an resource restricted platform. Based on the efficient channelization architecture, we designed a Dual-Input, 64K-Channelized prototype DBE with 1.2 GHz bandwidth on a Xilinx Virtex-6 LX240T Field Programmable Gate Array(FPGA) chip. The test results in the lab and observation results at Yunnan Observatory demonstrate the DBE can be used for radio astronomy.

P08046
The following article is Open access

, , , , , , , , , et al

Muon beams of low emittance provide the basis for the intense, well-characterised neutrino beams of a neutrino factory and for multi-TeV lepton-antilepton collisions at a muon collider. The international Muon Ionization Cooling Experiment (MICE) has demonstrated the principle of ionization cooling, the technique by which it is proposed to reduce the phase-space volume occupied by the muon beam at such facilities. This paper documents the performance of the detectors used in MICE to measure the muon-beam parameters, and the physical properties of the liquid hydrogen energy absorber during running.

P08045

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We have developed a solid state probe for an absolute irradiance calibration of the Thomson scattering system on the Large Plasma Device (LAPD), based on Raman scattering off silica. Measurements performed with a triple-grating spectrometer have investigated the intensities of a pulsed laser beam Raman scattered off crystalline and amorphous silica over a range of temperatures of relevance to the LAPD (299–498 K). The data were compared with Rayleigh and Raman scattering intensities in gaseous nitrogen. The measurements show that Raman scattering off quartz allows rapid and accurate alignment and calibration of Thomson scattering systems in plasma physics experiments that cannot be calibrated using conventional methods.

P08044

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While Cadmium Telluride (CdTe) excels in terms of photon radiation absorption properties and outperforms silicon (Si) in this respect, the crystal growth, characterization and processing into a radiation detector is much more complicated. Additionally, large concentrations of extended crystallographic defects, such as grain boundaries, twins, and tellurium (Te) inclusions, vary from crystal to crystal and can reduce the spectroscopic performance of the processed detector. A quality assessment of the material prior to the complex fabrication process is therefore crucial. To locate the Te-defects, we scan the crystals with infrared microscopy (IRM) in different layers, obtaining a 3D view of the defect distribution. This provides us with important information on the defect density and locations of Te inclusions, and thus a handle to assess the quality of the material. For the classification of defects in the large amount of IRM image data, a convolutional neural network is employed. From the post-processed and analysed IRM data, 3D defect maps of the CdTe crystals are created, which make different patterns of defect agglomerations inside the crystals visible. In total, more than 100 crystals were scanned with the current IRM setup. In this paper, we compare two crystal batches, each consisting of 12 samples. We find significant differences in the defect distributions of the crystals.

P08043

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The Compressed Baryonic Matter (CBM) experiment in the upcoming Facility for Antiproton and Ion Research (FAIR), designed to take data in nuclear collisions at very high interaction rates of up to 10 MHz, will employ a free-streaming data acquisition with self-triggered readout electronics, without any hardware trigger. A simulation framework with a realistic digitization of the detectors in the muon chamber (MuCh) subsystem in CBM has been developed to provide a realistic simulation of the time-stamped data stream. In this article, we describe the implementation of the free-streaming detector simulation and the basic data related effects on the detector with respect to the interaction rate.

P08042

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Geant4Reweight is an open-source C++ framework that allows users to weight tracks produced by the Geant4 particle transport Monte Carlo simulation according to hadron interaction cross section variations and estimate uncertainties in Geant4 interaction models by comparing the simulation's hadron interaction cross section predictions to data. The ability to weight hadron transport as simulated by Geant4 is crucial to the propagation of systematic uncertainties related to secondary hadronic interactions in current and upcoming neutrino oscillation experiments, including MicroBooNE, NOvA, and DUNE, as well as hadron test beam experiments such as ProtoDUNE. We provide motivation for weighting hadron tracks in Geant4 in the context of systematic uncertainty propagation, a description of Geant4's transport simulation technique, and a description of our weighting technique and fitting framework in the momentum range 0–10 GeV/c, which is typical for the hadrons produced by neutrino interactions in these experiments.

P08041

, , , , , , , , , et al

A variety of transition radiators consisting of polypropylene, foam, and sponge materials have been studied for the transition radiation detector in the High Energy cosmic-Radiation Detection (HERD) facility. The test was implemented at the Beijing Test Beam Facility (BTBF) using an electron beam with an energy of 2.5 GeV. It is a simple and effective method that used two identical detectors to study the photon yield efficiency of radiators and it is here denoted as the current ratio method. Based on this method, a parameter χ was defined to evaluate the absolute TR photon yield per electron of the radiator. The polypropylene radiator GXU0.5 × 300 demonstrated an excellent absolute yield of 4.05 ± 0.97 photons per electron. The experimental results were compared with the corresponding TR generation models in Geant4 and the difference between them in regular radiators was in the range of 1%-7%. The research results of absolute photon yield may provide some reference for future research on radiators.

P08040

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In the context of the ClearMind project, we measured the scintillating properties, as induced from gamma ray interactions, of today available PbWO4 crystal. We measured scintillation's yields and time constants by measuring the signal shape measured on a fast photo-multiplier and deconvoluting it from the instrumental effects. For the doped crystals at room temperature, we measured a fast scintillation component, with time constants of 2 ns, 55 % of the total light yield, and a slow component of 6 ns. We observe a significant increase of the light yield for the slow component when the temperature decreases and simultaneous increase of the time constants, but no increase in the fast component light yield. Our measurements reproduce the main qualitative features of PbWO4crystals quoted in the literature. Quantitatively though, we measured significantly shorter time constants and larger light yields. This is explained by a rigorous treatment of the instrumental contributions in the measurements. Results are discussed and prospect for future developments "tailored" for the ClearMind project are presented.

P08039

, and

The maximum achievable performance of strange-jet tagging at hadron colliders and the loss in performance in different detector designs is estimated based on simulated truth jets from strange-quark and down-quark hadronisation. Both jet types are classified with a recurrent neural network using long short-term memory units, at first using all available truth particles and then applying selections to study the impacts of ideal tracking detectors, Cherenkov detectors, and calorimeters. Additionally, a manual reconstruction of strange hadron decays such as KS → π+π- from charged tracks is considered.

P08038
The following article is Open access

, and

CUBES is a X-ray detector payload which will be installed on the KTH 3U CubeSat mission, MIST. The detector comprises cerium-doped Gd3Al2Ga3O12 (GAGG) scintillators read out with silicon photomultipliers through a Citiroc Application-Specific Integrated Circuit. The detector operates in the energy range ∼35–800 keV. The aim of the CUBES mission is to provide experience in the operation of these relatively new technologies in a high-inclination low earth orbit, thereby providing confidence for component selection in more complex satellite missions. The design of the CUBES detector is described, and results from performance characterisation tests carried out on a prototype of CUBES, called Proto-CUBES, are reported. Proto-CUBES was flown on a stratospheric balloon platform from Timmins, Canada, in August 2019. During the ∼12 hour long flight, the performance of Proto-CUBES was studied in the near-space environment. As well as measuring the X-ray counts spectra at different atmospheric depths, a 511 keV line from positron annihilation was observed.

P08037
The following article is Open access

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In 2007, the U.S. Congress mandated the implementation of the "Security and Accountability For Every Port Act of 2006," which requires complete scanning of 100% of U.S.-bound shipping containers. To address this requirement, we developed a container inspection method that enables continuous high-speed screening, with considerable performance improvement. In this study, we developed a fixed-type high-precision container inspection system using dual-angle X-ray beams from a 9 MV linear accelerator (LINAC). We first calculated the X-ray irradiation angle-dependent changes in the contrast-to-noise ratio (CNR) of the images via Monte Carlo simulation. Using the calculated CNRs, the primary and secondary angles of the X-ray beam were set to 0° and 2.8°, respectively. A system based on the proposed dual-angle X-ray imaging technology was installed and evaluated by scanning a real cargo container truck. For the evaluation, we designed test equipment based on the ANSI N42.46 report and examined the beam penetration power, contrast sensitivity, spatial resolution, and wire detectability of the developed system. The maximum penetration thicknesses for the primary and secondary angle beams were found to be 410 and 400 mm, respectively. At the primary beam angle, the contrast sensitivities were 1.52% and 0.49% when the thicknesses of the steel plate were 80% and 50% of the maximum penetration thickness, respectively. At the secondary angle, the sensitivities were 1.88% at 80% maximum penetration thickness, and 0.5% at 50%. A line pattern formed by individual slits of 4.6 mm width could be easily recognized in an acquired image. In addition, the developed system could clearly identify a 1.6 mm diameter copper wire. Further, when a steel plate was added, the change in the wire-recognition ability of the imaging system was found to be similar at both beam angles. These results indicate that the developed system is suitable for container screening using a 9 MV LINAC. Shapes that could not be identified from one beam irradiation angle could more accurately be analyzed using images from two different angles.

P08036
The following article is Open access

, , , , , , , , , et al

In micro-pattern gaseous detectors (MPGD) the evaluation of the space resolution with the charge centroid method provides large uncertainty when the incident particle is not perpendicular to the readout plane. An improvement of the position reconstruction is given by the microTPC (μTPC) algorithm: the three-dimensional reconstruction of the particle track inside the detector drift gap is performed using the arrival time of the induced signals on the readout. In this work we report the application of this method to the μ-RWELL detector that, combined with the charge centroid, allows to achieve an almost uniform resolution below 100 μm over a wide angular range.

P08035

, , , , , , , , , et al

The Payload for Ultrahigh Energy Observations (PUEO) long-duration balloon experiment is designed to have world-leading sensitivity to ultrahigh-energy neutrinos at energies above 1 EeV. Probing this energy region is essential for understanding the extreme-energy universe at all distance scales. PUEO leverages experience from and supersedes the successful Antarctic Impulsive Transient Antenna (ANITA) program, with an improved design that drastically improves sensitivity by more than an order of magnitude at energies below 30 EeV. PUEO will either make the first significant detection of or set the best limits on ultrahigh-energy neutrino fluxes.

P08034
The following article is Open access

, , , , , , , , , et al

IceCube is a cubic-kilometer Cherenkov telescope operating at the South Pole. The main goal of IceCube is the detection of astrophysical neutrinos and the identification of their sources. High-energy muon neutrinos are observed via the secondary muons produced in charge current interactions with nuclei in the ice. Currently, the best performing muon track directional reconstruction is based on a maximum likelihood method using the arrival time distribution of Cherenkov photons registered by the experiment's photomultipliers. A known systematic shortcoming of the prevailing method is to assume a continuous energy loss along the muon track. However at energies >1 TeV the light yield from muons is dominated by stochastic showers. This paper discusses a generalized ansatz where the expected arrival time distribution is parametrized by a stochastic muon energy loss pattern. This more realistic parametrization of the loss profile leads to an improvement of the muon angular resolution of up to 20% for through-going tracks and up to a factor 2 for starting tracks over existing algorithms. Additionally, the procedure to estimate the directional reconstruction uncertainty has been improved to be more robust against numerical errors.

P08033
The following article is Open access

, , , , , , , , , et al

Photomultiplier tubes (PMTs) are often used in low-background particle physics experiments, which rely on an excellent response to single-photon signals and stable long-term operation. In particular, the Hamamatsu R11410 model is the light sensor of choice for liquid xenon dark matter experiments, including XENONnT. The same PMT model was also used for the predecessor, XENON1T, where issues affecting its long-term operation were observed. Here, we report on an improved PMT testing procedure which ensures optimal performance in XENONnT. Using both new and upgraded facilities, we tested 368 new PMTs in a cryogenic xenon environment. We developed new tests targeted at the detection of light emission and the degradation of the PMT vacuum through small leaks, which can lead to spurious signals known as afterpulses, both of which were observed in XENON1T. We exclude the use of 26 of the 368 tested PMTs and categorise the remainder according to their performance. Given that we have improved the testing procedure, yet we rejected fewer PMTs, we expect significantly better PMT performance in XENONnT.

P08032

, , , , , , , , , et al

Multilayer position-sensitive 10B-RPC thermal neutron detectors offer an attractive combination of sub-millimeter spatial resolution and high (>50%) detection efficiency. Here we describe a new position reconstruction method based on a statistical approach. Using experimental data, we compare the performance of this method with that of the centroid reconstruction. Both methods result in a similar image linearity/uniformity and spatial resolution. However, the statistical method allows to improve the image quality at the detector periphery, offers more flexible event filtering and allows to develop automatic quality monitoring procedures for early detection of situations when a change in the detector operation conditions starts to affect reconstruction quality.

P08031

, , , and

People counting plays a crucial role in various sensing applications such as in smart cities and shopping malls. In this paper, we propose a data-driven solution that uses a low power ultra-wideband impulse (UWB) radar to count the number of random walking people in an indoor space. A pre-processing signal processing method is applied to clean clutter signals from UWB radar. Instead of the conventional counting methods, which manually extract features and learned from effective data patterns, we investigated deep convolutional neural networks (CNNs) that automatically learn from the data to count the number of people in an indoor space. The CNN model could accurately predict up to 97% accuracy for up to 10 people random walking in an area of 5 × 5 m. The different settings of the CNN models, such as the data input window size, and kernel size in each layer, will be investigated.

P08030

, , and

Time Projection Chambers (TPCs) operated at high pressure have become a topic of interest for future long baseline neutrino experiments. Pressurized gas retains the low momentum threshold for particle detection of atmospheric TPCs, but offers a larger target mass for neutrino interactions at the same volume. Operation at high pressure poses several new challenges in safety aspects regarding overpressure and high voltage safety. The presented High Pressure Gas Monitoring Chamber (HPGMC) can be used to study the suitability of various drift gas mixtures up to 10 bar and a maximum field of ∼ 3000 V/cm. A flexible construction makes it possible to exchange parts of the inner detector and to test new technologies. In this work, the construction of a HPGMC and its commissioning using the P10 gas mixture (90 % Ar + 10 % CH4) are presented.

P08029

, , , , , , , and

We report results of fast neutron response in plastic scintillator (PS) bars from deuterium-deuterium (D-D) and deuterium-tritium (D-T) reactions using Purnima Neutron Generator Facility, BARC, Mumbai. These measurements are useful in context of Indian Scintillator Matrix for Reactor Anti-Neutrino (ISMRAN) detection, an array of 10×10 PS bars, used to measure reactor anti-neutrinos through inverse beta decay (IBD) signal. ISMRAN detector, an above-ground experiment close to the reactor core (∼13m), deals with an active fast neutron background inside the reactor hall. A good understanding of fast neutron response in PS bars is an essential pre-requisite for suppression and discrimination of fast neutron background from IBD events. A monoenergetic neutron beam from the fusion reaction of D-D at 2.45 MeV and D-T at 14.1 MeV are used to characterize the energy response in these bars. The neutron energy response function has been simulated using the GEANT4 package and are compared with the measured data. A reasonable agreement of deposited energies by fast neutrons in PS bars between data and simulation are obtained for these reactions. The ratio of energy deposition in adjacent bars is used to discriminate between prompt IBD, fast neutron and neutron capture cascade gamma events.

P08028

, , and

In the near future there will be the request for very large liquid Xenon (LXe) detectors for Dark Matter (DM) searches in the 50-ton range. To avoid an impractically long, single drift space of a dual-phase detector, it seems beneficial to use the single-phase technique. Since electrons then can drift in any direction, we can segment the homogeneous medium and thus avoid an excessive maximum drift path of order 4 m. The shorter detector length has several benefits, e.g. requiring a lower cathode voltage for the same drift field. We can easily split the TPC into two regions with the cathode in the center and two anodes at the top and bottom. One also can use multiple TPCs stacked on top of each other in the same liquid volume to reduce the maximum drift length even further. A further division of the drift space by installing an additional anode in the center would require S2 photons to traverse the liquid for several times the Rayleigh scattering length in LXe, which is only 30–40 cm. This seems to be excessive for good x-y localization. We therefore suggest a geometry of two independent TPCs with two drift spaces each. Despite earlier publications concerns persisted about the effect of shadowing. A detailed FEM model of the anode regions shows that with an aligned wire arrangement the drifting electrons impinge sideways on the anode in a narrow angular range of width 15°–20°. Most S2 photons are emitted in full view of the close-by PMT array. About 37% of the S2 photons are shadowed by the anode wire out of which 30% will be reflected back again on the gold plating of the wires. Thus we can observe 74% of the total S2 light. Compared to a dual-phase detector, however, we do not suffer from the extraction efficiency, sometimes reported as low as 50%.

P08027

, , , , , , , , , et al

Cadmium telluride is a favorable material for X-ray detection as it has an outstanding characteristic for room temperature operation. It is a high-Z material with excellent photon radiation absorption properties. However, CdTe single crystals may include a large number of extended crystallographic defects, such as grain boundaries, twins, and tellurium (Te) inclusions, which can have an impact on detector performance. A Technology Computer Aided Design (TCAD) local defect model has been developed to investigate the effects of local defects on charge collection efficiency (CCE). We studied a 1 mm thick Schottky-type CdTe radiation detector with transient-current technique by using a red laser at room temperature. By raster scanning the detector surface we were able to study signal shaping within the bulk, and to locate surface defects by observing their impact on the CCE. In this paper we present our TCAD model with localized defect, and compare the simulation results to TCT measurements. In the model an inclusion with a diameter of 10 μm was assumed. The center of the defect was positioned at 6 μm distance from the surface. We show that the defect has a notable effect on current transients, which in turn affect the CCE of the CdTe detector. The simulated charge collection at the position of the defect decreases by 80 % in comparison to the defect-free case. The simulations show that the defects give a characteristic shape to TCT signal. This can further be used to detect defects in CdTe detectors and to estimate the overall defect density in the material.

P08026

, , and

Monocrystalline SiC, Si and Diamond detectors have been used to monitor the radiations emitted from TNSA laser-generated plasma using a high-intensity fs laser. The comparison of their spectra was performed monitoring in time-of-flight the forward emitted TNSA plasma radiation. Carbon, aluminum, copper and gold targets were irradiated with an intensity of the order of 1019 W/cm2. SiC detector, with 80 microns depth active region, gave the best response to detect fast UV and X-rays, relativistic and cold electrons, and energetic protons and light accelerated ions. The experiments demonstrate the advantages to use semiconductor detectors to characterize the plasma enhancing the importance of the thickness of the target with respect to its electronic density.

P08025
The following article is Open access

, , , , , , , , , et al

Non-ionizing energy loss causes bulk damage to the silicon sensors of the ATLAS pixel and strip detectors. This damage has important implications for data-taking operations, charged-particle track reconstruction, detector simulations, and physics analysis. This paper presents simulations and measurements of the leakage current in the ATLAS pixel detector and semiconductor tracker as a function of location in the detector and time, using data collected in Run 1 (2010–2012) and Run 2 (2015–2018) of the Large Hadron Collider. The extracted fluence shows a much stronger |z|-dependence in the innermost layers than is seen in simulation. Furthermore, the overall fluence on the second innermost layer is significantly higher than in simulation, with better agreement in layers at higher radii. These measurements are important for validating the simulation models and can be used in part to justify safety factors for future detector designs and interventions.

P08024

, and

The paper presents the results obtained from the study of a radiofrequency (RF) oscillator developed for use in an RF ion source, for the development of a low energy charged particle accelerator. An investigation was made on the main factors attributing to the operating frequency of the oscillator. Four different RF coils are constructed using a copper tube for studying the different operating frequencies. The RF output power was measured using a modified form of the photometric method. The variation of RF power with operating frequency are discussed.

P08023

, , , , , , , , , et al

The KamLAND-Zen 800 experiment is searching for the neutrinoless double-beta decay of 136Xe by using 136Xe-loaded liquid scintillator. The liquid scintillator is enclosed inside a balloon made of thin, transparent, low-radioactivity film that we call Inner Balloon (IB). The IB, apart from guaranteeing the liquid containment, also allows to minimize the background from cosmogenic muon-spallation products and 8B solar neutrinos. Indeed these events could contribute to the total counts in the region of interest around the Q-value of the double-beta decay of 136Xe. In this paper, we present an overview of the IB and describe the various steps of its commissioning minimizing the radioactive contaminations, from the material selection, to the fabrication of the balloon and its installation inside the KamLAND detector. Finally, we show the impact of the IB on the KamLAND background as measured by the KamLAND detector itself.

P08022

, , , , and

This paper reports the manufacturing methodology to produce an electron multiplier, a Micromegas device, integrated onto a micro-pixel readout anode using a Silicon wafer as a holder. It describes the improvement in the processing of the insulating grid material SU-8 and electrical tests with the device. For the latter purpose, simulations with Garfield++ are carried out to predict the detector response for different gas mixtures. The Micromegas detector sandwich proposed in this work presents a series of problems, which we have addressed and discussed within this paper. The temperature control throughout the processing of SU-8 is extremely important, to be able to develop it. When developing the final SU-8 layer, we have used an extra photoresist, which combined with the SU-8, resulted in a much-improved shape of the Micromegas SU-8 hole-grid. Electrical testes are performed in order to verify the signals produced by a 55Fe radioactive source. A gas gain about 1,3 × 102, using Ar/C2H6 (75/25) mixture, is achieved for the prototype manufactured.

P08021

, , , , , and

The Super Tau-Charm Facility (STCF) is a future electron-positron collider proposed in China with a peak luminosity of above 0.5 × 1035 cm-2s-1 and center-of-mass energy ranging from 2 to 7 GeV. An excellent particle identification (PID) capability is one of the most important requirements for the detector at the STCF. A 3σ π/K separation power at the momentum of up to 2 GeV/c is required within the detector acceptance. A DIRC-like time-of-flight (DTOF) detector is proposed to meet the PID requirement for the endcap region of the STCF. The conceptual design of the DTOF detector and its geometry optimization is herein presented. The PID performance of the detector is studied using Geant4 simulation. With a proper reconstruction algorithm, an overall time resolution of ∼50 ps is achieved for the detector with an optimum geometry when convoluting contributions from all other sources, including the transit time spread (TTS) of the photodetector, electronic timing accuracy, and an assumed precision (∼40 ps) of the event start time. A π/K separation power of better than 4σ at the momentum of 2 GeV/c is achieved over the entire sensitive area of the DTOF detector, thereby fulfilling the physics requirement of the PID detector for the experiment at the STCF.

P08020

, , , , , and

Micro Pattern Gaseous Detector (MPGD) is a promising and competitive technology for thermal neutron imaging, due to its many advantages such as high counting rate, low mass, irradiation resistance, and excellent position resolution. In order to further improve spatial resolution, a vertex reconstruction of neutron conversion tracks can be employed. Moreover, the accompanying γ-ray background also has a significant impact on the detector performance. In this work, a detector for thermal neutron detection was developed based on GEMs, with a B4C-coated Mylar foil as the converter. Track reconstruction and vertex correction were achieved with additional use of the information of each signal. The rising time and energy were utilized to improve the track reconstruction furthermore. Finally, the spatial resolution was improved to 0.23 mm from 1.01 mm significantly for thermal neutron detection.

P08019

, , , , , , , and

We present a new scheme for the realization of ultrashort terahertz (THz) radiation pulses by electron beam with a frequency-chirped microbunching structure travelling in a tapered undulator. In this proposal, a longitudinally modulated laser pulse with a chirp rate in the instantaneous modulation frequency is obtained through the optical beating of dual-chirp pulses; then the chirped micro-structure is converted to a chirped density modulation on electron beams by the laser-electron interaction and dispersion effect; finally by sending this electron beam into a designed undulator, ultrashort pulse and broad-band THz radiation can be produced. Considering the fact that the density modulation of the electron beam is directly inherited from the shaped laser, the central frequency and chirp rate can be easily tuned by the optical elements. Numerical simulations confirm that radiation pulses with ultrashort duration can be generated from such a microbunched electron beam. This technique may open new research avenues for strong-field few-cycle THz photonics.

P08018

, , and

We study the elasto-optic behaviour of monoclinic and trigonal crystals. The eigenvalues and eigenvectors of the dielectric impermeability tensor under stress are evaluated by the means of the approximated formulae obtained by Sirotin. The parameters which characterize Bertin's surfaces and fringe patterns in conoscopic observation are determined as functions of either residual or applied stress. Later, the photoelastic constants, and the rotation of the optic plane and optic axes bisector are estimated in order to allow for the evaluation of the residual or applied stress by conoscopic measurements. Finally, we obtain the dependence of the refraction indices on the stress. The knowledge of these crystal properties is mandatory for applications in high physics energy, security, geological prospection and in crystals for photonics and medical applications. The evaluated photoelastic constants allow the development of methodologies for an easy and fast quality control via stress distribution detections by means of conoscopic observation, even for strongly anisotropic crystals. As a case study we apply these results to the cases of monoclinic Lu2(1-x)Y2xSiO5(LYSO) and trigonal LiNbO3 (Lithium Niobate).

P08017

, , and

This paper presents the novel design of an interposed pulsed power system, developed to drive a fast-switching magnet with a large multi-mH load inductance, and high field amplitude (> 1 T). This modulator can produce variable flat-top pulses from 1 to 30 ms with rise and fall times of less than 0.5 ms at a variable duty cycle of 3–91% into a heavily inductive load. The system employs a novel over-voltage topology to overcome the inherent inductance and achieve the fast rise and fall times, switching to a precision DC supply to efficiently maintain the flattop without requiring many-kV voltage. We present a power source design consideration, including the results of computer modeling as well as the first experimental results of a modulator scaled test model will also be presented.

P08016

, , , , , and

We present a novel implementation of classification using the machine learning/artificial intelligence method called boosted decision trees (BDT) on field programmable gate arrays (FPGA). The firmware implementation of binary classification requiring 100 training trees with a maximum depth of 4 using four input variables gives a latency value of about 10 ns, independent of the clock speed from 100 to 320 MHz in our setup. The low timing values are achieved by restructuring the BDT layout and reconfiguring its parameters. The FPGA resource utilization is also kept low at a range from 0.01% to 0.2% in our setup. A software package called achieves this implementation. Our intended user is an expert in custom electronics-based trigger systems in high energy physics experiments or anyone that needs decisions at the lowest latency values for real-time event classification. Two problems from high energy physics are considered, in the separation of electrons vs. photons and in the selection of vector boson fusion-produced Higgs bosons vs. the rejection of the multijet processes.

P08015
The following article is Open access

, , , , , , , , , et al

The channeling process in bent silicon crystals are used since '70s to manipulate beams of high energy particles. During the last decade, several studies and experiments carried out by the UA9 Collaboration at CERN demonstrated the possibility to use bent crystals for beam collimation, extraction, focusing and splitting in particle accelerators. These crystals are subject to deterioration due to the interaction of the particles with the crystal lattice, degrading the beam steering performance. For this reason, robustness tests are crucial to estimate their reliability and operational lifetime. A ∼8% of reduction in channeling efficiency on crystals irradiated with 2.5·1021/cm2 thermal neutrons was measured and reported in this manuscript. Extrapolations to possible operational scenarios in high energy accelerators are also discussed.

P08014

, , , , and

Located at the center of the end of the CSR External-target Experiment (CEE), the Zero Degree Calorimeter (ZDC) is designed to rebuild the centrality and reaction plane of the nuclear-nuclear collision. To meet the target of ZDC to detect the energy distribution of colliding particles, a high-performance readout system prototype, which implements a Gaussian shaping algorithm, has been designed. The system consists of 4 channels; each channel mainly includes an I-V conversion circuit, a slow forming circuit, a threshold trigger circuit, and a digital signal processing unit based on a field-programmable gate array (FPGA).Performance studies indicate that the noise of each channel is less than 0.8 mV and the nonlinearity is better than 0.6%. Tests with a LED driver source indicate that the Gaussian shaping algorithm can improve the photon energy resolution from 7.481% to 6.196%. Tests with cosmic rays also produced expected results.

P08013

, , , , , , , , , et al

We present the characterization and quality control test of a gigabit cable receiver ASIC prototype, GBCR2, for the ATLAS Inner Tracker pixel detector upgrade. GBCR2 equalizes and retimes the uplink electrical signals from RD53B through a 6 m Twinax AWG34 cable to lpGBT. GBCR2 also pre-emphasizes downlink command signals through the same electrical connection from lpGBT to RD53B. GBCR2 has seven uplink channels each at 1.28 Gbps and two downlink channels each at 160 Mbps. The prototype is fabricated in a 65 nm CMOS process. The characterization of GBCR2 has been demonstrated that the total jitter of the output signal is 129.1 ps (peak-peak) in the non-retiming mode or 79.3 ps (peak-peak) in the retiming mode for the uplink channel and meets the requirements of lpGBT. The total power consumption of all uplink channels is 87.0 mW in the non-retiming mode and 101.4 mW in the retiming mode, below the specification of 174 mW. The two downlink channels consume less than 53 mW. A quality control test procedure is proposed and 169 prototype chips are tested. The yield is about 97.0%.

P08012

, , , and

This paper presents a novel method of searching for boosted hadronically decaying objects by treating them as anomalous elements of a contaminated dataset. A Variational Recurrent Neural Network (VRNN) is used to model jets as sequences of constituent four-vectors. After applying a pre-processing method which boosts each jet to the same reference mass, energy, and orientation, the VRNN provides each jet an Anomaly Score that distinguishes between the structure of signal and background jets. The model is trained in an entirely unsupervised setting and without high level variables, making the score more robust against mass and pTcorrelations when compared to methods based primarily on jet substructure. Performance is evaluated on the jet level, as well as in an analysis context by searching for a heavy resonance with a final state of two boosted jets. The Anomaly Score shows consistent performance along a wide range of signal contamination amounts, for both two and three-pronged jet substructure hypotheses. Analysis results demonstrate that the use of Anomaly Score as a classifier enhances signal sensitivity while retaining a smoothly falling background jet mass distribution. The model's discriminatory performance resulting from an unsupervised training scenario opens up the possibility to train directly on data without a pre-defined signal hypothesis.

P08011

Dual phase time projection chamber using liquid xenon as target material is one of most successful detectors for dark matter direct search, and has improved the sensitivities of searching for weakly interacting massive particles by almost five orders of magnitudes in past several decades. However, it still remains a great challenge for dual phase liquid xenon time projection chamber to be used as the detector in next-generation dark matter search experiments (∼ 50 tonne sensitive mass), in terms of reaching sufficiently high field strength for drifting electrons, and sufficiently low background rate. Here we propose a single phase liquid xenon time projection chamber with detector geometry similar to a Geiger counter, as a potential detector technique for future dark matter search, which trades off field uniformity for less isolated charge signals. Preliminary field simulation and signal reconstruction study have shown that such single phase time projection chamber is technically feasible and can have sufficiently good signal reconstruction performance for dark matter direct search.

P08010

, , , , , , , , , et al

A non-parasitic muon production facility (HEMS, abbreviation of High rEpetition rate Muon Source) at China Spallation Neutron Source (CSNS) is proposed. HEMS will extract a 500 MeV proton beam from a proton storage ring with a circumference of 80 m to bombard a target on a linear section at a repetition rate of 100 Hz. After bombarding the target, the beam will be injected back into the proton storage ring. The proton beam will be extracted and injected repeatedly to the proton storage ring 20 times within 20 ms. For injection and extraction kicker system, the repetition rate of pulser should be as high as 1 kHz. In addition, to achieve a large kick angle with a high magnet gap aperture in a relatively small beam lattice, kicker pulser is required to generate a large excitation current. The primary challenge is to build a high repetition rate, high current, and fast injection and extraction kicker system. To achieve these requirements, a 6.25 Ω impedance matching kicker system, mainly composed of a twin-C transmission line kicker magnet and inductive adder, is developed. In this paper, we report the conceptual design of the kicker magnet and kicker pulser for HEMS.

P08009
The following article is Open access

, , , , , , , , , et al

Test beam measurements have been carried out with a 3D sensor on a Timepix3 ASIC and the time measurements are presented. The measurements are compared to those of a thin planar sensor on Timepix3. It is shown that for a perpendicularly incident beam the time resolution of both detectors is dominated by the Timepix3 front-end. The 3D detector is dominated by the time-to-digital conversion whereas the analog front-end jitter also gives a significant contribution for the thin planar detector. The 3D detector reaches an overall time resolution of 567 ± 6 ps compared to 683 ± 8 ps for the thin planar detector. For a grazing angle beam, however, the thin planar detector achieves a better time resolution because it has a lower pixel capacitance, and therefore suffers less from jitter in the analog front-end for the low charge signals that mainly occur in this type of measurement. Finally, it is also shown that the 3D and thin planar detector can achieve time resolutions for large clusters of about 100 ps and 250 ps, respectively, by combining many single hit measurements.

P08008

, , , , , , and

We present a position-sensitive neutron detection technique based on a Commercial Off-The-Shelf CMOS image sensor (CIS) covered with nanoparticles of sodium gadolinium fluoride (NaGdF4). The synthesis procedure and characterization of the NaGdF4 nanoparticles are detailed, as well as the deposition method of the conversion layers over the surface of the chips. We also present a manufacture method of test patterns made with neutron-absorbing materials. These patterns were designed to evaluate the performance of the proposed technique. Analyzing the obtained neutron images we conclude that the intrinsic spatial resolution of the developed method is better than (15±6) μm, this upper bound for the spatial resolution is comparable with that obtained with the best neutron position-sensitive detectors available nowadays.

P08007
The following article is Open access

, , , , , and

The open-source software packageSolidStateDetectors.jl to calculate the fields and simulate the drifts of charge carriers in solid state detectors, especially in large volume high-purity germanium detectors, together with the corresponding pulses, is introduced. The package can perform all calculations in full 3D while it can also make use of detector symmetries. The effect of the surroundings of a detector can also be studied. The package is programmed in the user friendly and performance oriented language julia, such that 3D field calculations and drift simulations can be executed efficiently and in parallel. The package was developed for high-purity germanium detectors, but it can be adjusted by the user to other types of semiconductors. The verification of the package is shown for an n-type segmented point-contact germanium detector. Additional features of SolidStateDetectors.jl, which are under development are listed.

P08006

, , , , , , , , , et al

We present the procedures and results of the quality control tests for the front-end optical link components in the ATLAS Liquid Argon Calorimeter Phase-1 upgrade. The components include a Vertical-Cavity Surface-Emitting Laser (VCSEL) driver ASIC LOCld, custom optical transmitter/transceiver modules MTx/MTRx, and a transmitter ASIC LOCx2. LOCld, MTx, and LOCx2 each contain two channels with the same structure, while MTRx has a transmitter channel and a receiver channel. Each channel is tested at 5.12 Gbps. A total of 5341 LOCld chips, 3275 MTx modules, 797 MTRx modules, and 3198 LOCx2 chips are qualified. The yields are 73.9%, 98.0%, 98.4%, and 61.9% for LOCld, LOCx2, MTx, and MTRx, respectively.

P08005

and

Incom Inc. Large Area Picosecond Photodetector (LAPPD) 38 has been tested at Jefferson Lab to identify single-photoelectron signals to assess the potential of this type of device for future applications in Cherenkov light detection. Single-photoelectron signals were clearly detected if a tight masking of photons impinging on the photocathode was used compared to the pixelation of the charge collection signal board.

P08004

, , , , , , , , and

HEPS-BPIX3 is a hybrid pixel detector readout chip for X-ray applications for the High Energy Photon Source (HEPS) in China. The readout chip contains an array of 88 × 88 pixels with a pixel size of 55 μm × 55 μm, working in single photon counting mode. Each pixel handles both polarities of positive and negative input charge signals and has a counting depth of 11 bits. Using a clock with a frequency up to 160 MHz, the chip can read out serially with zero dead time. Designed in a 130 nm CMOS technology, the chip has been measured and given the CSA charge gain of 17.6 mV/ke- for electron collection and 13 mV/ke- for hole collection, respectively. Bump-bonded detector modules with a 320-μm-thick silicon sensor were also tested. The test results showed an equivalent input noise of 156 e- and a counting rate up to 2.2 Mcps. Besides, an image using an X-ray tube was demonstrated and a frame rate of 1.8 kHz could be guaranteed. Measured characteristics present the normal functionality of the HEPS-BPIX3 chip and prove that the chip satisfies the HEPS requirements.

P08003

, , , , , , , , , et al

Metallic magnetic micro-calorimeters (MMCs) operated at millikelvin temperature offer the possibility to achieve eV-scale energy resolution with high stopping power for X-rays and massive particles in an energy range up to several tens of keV. This motivates their use in a wide range of applications in fields as particle physics, atomic and molecular physics. Present detector systems consist of MMC arrays read out by 32 two-stage SQUID read-out channels. In contrast to the design of the detector array and consequently the design of the front-end SQUIDs, which need to be optimised for the physics case and the particles to be detected in a given experiment, the read-out chain can be standardised. We present our new standardised 32-channel parallel read-out for the operation of MMC arrays to be operated in a dilution refrigerator. The read-out system consists of a detector module, whose design depends on the particular application, an amplifier module, ribbon cables from room temperature to the millikelvin platform and a data acquisition system. In particular, we describe the realisation of the read-out system prepared for the ECHo-1k experiment for the operation of two 64-pixel arrays. The same read-out concept is also used for the maXs detector systems, developed for the study of the de-excitation of highly charged heavy ions by X-rays, as well as for the MOCCA system, developed for the energy and position sensitive detection of neutral molecular fragments for the study of fragmentation when molecular ions recombine with electrons. The choice of standard modular components for the operation of 32-channel MMC arrays offer the flexibility to upgrade detector modules without the need of any changes in the read-out system and the possibility to individually exchange parts in case of damages or failures.

P08002

, , , , , , , , , et al

Silicon photomultipliers are regarded as a very promising technology for next-generation, cutting-edge detectors for low-background experiments in particle physics. This work presents systematic reflectivity studies of Silicon Photomultipliers (SiPM) and other samples in liquid xenon at vacuum ultraviolet (VUV) wavelengths. A dedicated setup at the University of Münster has been used that allows to acquire angle-resolved reflection measurements of various samples immersed in liquid xenon with 0.45° angular resolution. Four samples are investigated in this work: one Hamamatsu VUV4 SiPM, one FBK VUV-HD SiPM, one FBK wafer sample and one Large-Area Avalanche Photodiode (LA-APD) from EXO-200. The reflectivity is determined to be 25–36 % at an angle of incidence of 20° for the four samples and increases to up to 65 % at 70° for the LA-APD and the FBK samples. The Hamamatsu VUV4 SiPM shows a decline with increasing angle of incidence. The reflectivity results will be incorporated in upcoming light response simulations of the nEXO detector.

P08001

, , , , , , , and

We present a new system for high repetition rate and real-time pulse analysis implemented at the Monoenergetic Positron Source (MePS) at the superconducting electron LINAC ELBE at Helmholtz-Zentrum Dresden-Rossendorf. Dedicated digital signal processing and optimized algorithms are employed allowing for high bandwidth throughput, online pulse analysis and filtering. Positrons generated from radioisotopes and from bremsstrahlung pair production by means of highly intense accelerator-based positron beams serve as a microstructure probe allowing material characterizations with respect to chemical, mechanical, electrical, and magnetic properties. Positron annihilation lifetime events with up to 13 MHz repetition rate are being processed online without losses while performing signal selections for pile-up reduction, online energy calibration, and — for radioisotope-based measurements — identification of start and stop events.

Conference proceedings

C08003

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For performing a study of impurity transport efficiently by using a Tracer-Encapsulated Solid Pellet (TESPEL) in Large Helical Device (LHD), a new double-barreled TESPEL injection system was recently developed and installed on the LHD. The TESPEL in each injection line can be injected with different timing and acceleration pressure which can be set individually. To prevent the high-pressured gas for the TESPEL acceleration from getting into the vacuum vessel of the LHD, a 3-stage differential pumping scheme was applied. Since the available space is very limited, the 3-stage differential pumping system is shared with each TESPEL injection line. And for the same reason, one of the guide tubes in one injection line of the new TESPEL injection system was purposely bent (bending radius of about 40 m). The guide tubes in the other injection line of the new TESPEL injection system are straight. We performed a laboratory test to check the TESPEL transferring capability with the guide tubes in the new injection system. The points of TESPEL impact on the target foil are found to be within the circles defined by a possible pellet divergence full angle, 2 degrees. Therefore, we confirmed that the TESPEL can pass through both the slightly bent and the straight injection lines of the new injection system without any problem. The blank shot test shows that the increment of the total pressure even by using both the injection lines simultaneously is much below the base pressure of the LHD vacuum vessel during the discharge. This result successfully demonstrated the capability of the applied 3-stage differential pumping scheme in the new injection system.

C08002

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The Control Unit of the KM3NeT Data Acquisition is the software suite that is responsible for operating all the components of the KM3NeT telescopes in a coordinated and scientifically proficient way. It controls a wide span of parameters and procedures, from the power supplies, to the operating voltages of more than 64000 photomultipliers in each detector block, to the setup of the various trigger algorithms that are applied online. The same software suite is also designed to be used in all test and qualification benches, from single Digital Optical Modules to full Detection Units. As the KM3NeT detectors are being incrementally built, the Control Unit is employed in a variety of setups and configurations, and is a dynamic software project, still adapting to shifting needs. The conflicting requirements of flexibility and stability are reconciled by proper code development policies. The Control Unit is able to cope with dynamically changing scenarios of multiple firmware generations coexisting in the same detector, for various reasons including hardware compatibility as well as testing purposes. The code also allows for static verification and extensive unit tests. A Central Logic Board Simulator software was also developed to help testing the whole architecture. Such a simulator provides properly faked slow control parameters, features a fully specification-compliant state machine and can generate fake data with specific profiles to feed the Trigger and Data Acquisition System. In this way, offline integration tests can be executed at each new software release, ensuring their smooth deployment to production sites and minimising chances of mistakes by operators.

C08001

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While there is evidence for the existence of dark matter, its properties have yet to be discovered. Simultaneously, the nature of high-energy astrophysical neutrinos detected by IceCube remains unresolved. If dark matter and neutrinos are coupled to each other, they may exhibit a non-zero elastic scattering cross section. Such an interaction between an isotropic extragalactic neutrino flux and dark matter would be concentrated in the Galactic Centre, where the dark matter column density is greatest. This scattering would attenuate the flux of high-energy neutrinos, which could be observed in IceCube. Using the seven-year Medium Energy Starting Events, we perform an unbinned likelihood analysis, searching for a signal based on a possible dark matter-neutrino interaction scenario. We search for a suppression of the high-energy astrophysical neutrino flux in the direction of the Galactic Centre, and compare these constraints to complementary low-energy information from large scale structure surveys and the cosmic microwave background.

Technical reports

T08017

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A two-dimensional neutron detector consisting of 96 3He position-sensitive proportional counters was assembled at the China Mianyang Research Reactor. With a count rate limit that is higher than that of the initial multi-wire proportional chamber detector at CMRR, it will be used for the small-angle neutron scattering spectrometer Suanni. The problems caused by low air pressure and γ radiation in the working environment are pretreated, and detector performance is evaluated and compared with that of the initial proportional chamber. Now the new detector is ready to be used for Suanni.

T08016
The following article is Open access

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Acquisition and analysis of time-tagged events is a ubiquitous tool in scientific and industrial applications. With increasing time resolution, number of input channels, and acquired events, the amount of data can be overwhelming for standard processing techniques. We developed the Extensible Time-tag Analyzer (ETA), a powerful and versatile, yet easy to use software to efficiently analyze and display time-tagged data. Our tool allows for flexible extraction of correlation from time-tagged data beyond start-stop measurements that were traditionally used. A combination of state diagrams and simple code snippets allows for analysis of arbitrary complexity while keeping computational efficiency high.

T08015
The following article is Open access

, , , , , , , , , et al

The KArlsruhe TRItium Neutrino (KATRIN) experiment, which aims to make a direct and model-independent determination of the absolute neutrino mass scale, is a complex experiment with many components. More than 15 years ago, we published a technical design report (TDR) [1] to describe the hardware design and requirements to achieve our sensitivity goal of 0.2 eV at 90% C.L. on the neutrino mass. Since then there has been considerable progress, culminating in the publication of first neutrino mass results with the entire beamline operating [2]. In this paper, we document the current state of all completed beamline components (as of the first neutrino mass measurement campaign), demonstrate our ability to reliably and stably control them over long times, and present details on their respective commissioning campaigns.

T08014

, , , , , , , , , et al

The Experimental Complex (EC) NEVOD includes a number of detectors used to carry out basic research of cosmic rays (CR) and their interactions in the energy range 1011–1019 eV and applied research of the heliosphere, magnetosphere and atmosphere of the Earth by the muonography method which is based on the analysis of spatial-angular variations of the muon flux generated by primary CR particles with energies of 10^9–10^11 eV. The EC NEVOD is being constantly developed. Nowadays, it consists of three basic groups of experimental facilities unique in the world: the major facilities (Cherenkov water detector NEVOD, calibration telescope system — CTS, coordinate-tracking detector DECOR), the peripheral facilities (extensive air shower array NEVOD-EAS, distributed thermal neutron detector systems PRISMA and URAN), the muon hodoscopes for cosmophysical and geophysical investigations (TEMP and URAGAN). All detectors and installations of the first two groups are combined by a multilevel triggering system and the time synchronization system ensuring timestamping of registered multicomponent events. Today, the Experimental Complex NEVOD is the only facility capable of studying such a wide set of fundamental and applied scientific problems in the field of cosmic rays and solar-terrestrial physics.

T08013

, , , , , , , , , et al

The 5.5 MV CN-Van de Graaff (VDG) accelerator was first installed and operated in the early 50's at Rice University (Houston, TX) and it was donated to IFUNAM ("Instituto de Física, Universidad Nacional Autónoma de México") in 1984 and started a new life in 1988. At the end of 2017, the ion source was severely damaged. Several power supplies were destroyed. In this article we describe the process of restoring the VDG terminal. A number of power supplies were redesigned, built, tested and mounted in the Terminal. As a result of the work carried out during most of 2019, the VDG accelerator is now operational and we show data from the Rutherford Backscattering (RBS) analysis of a platinum coated silicon slab using the first proton and α beams. Electronic diagrams of all supplies in their new configuration are provided for the benefit of this kind of RF-Ion sources users still numerous.

T08012

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Aiming at the problem that attitude changes will cause sway errors of the fluxgate, firstly, the attitude change error model is constructed theoretically, and the influence of attitude changes on the three-axis fluxgate is analyzed; secondly, in order to improve measurement accuracy of the fluxgate, reduce the measurement error caused by the change of attitude, the calibration method for sway error of fluxgate is proposed. Furthermore, the error calibration model is established. Finally, the effectiveness of the method is verified by simulation and actual experiment. The uniaxial absolute error can be up to 4.64% at a minimum. The calibration effect is good, and the calibrated data can basically meet actual needs.

T08011

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A quasi-optical Mach-Zehnder microwave interferometer operating at 140 GHz has been developed for the ENN's spherical tokamak XuanLong-50 (EXL-50), for the purposes of line-integral electron density measurement and plasma density real-time feedback control input. The EXL-50 is designed for long pulse operation (over 5 s) and the electron density of phase I is estimated below 1019 m-3. Thus, the well-known microwave interferometer is suitable for the advantage of cost effectiveness and good stability. One of the major errors of the interferometer is vibration. To reduce it, the entire interferometer is supported by sand-filled stainless-steel columns of 0.3 m inner diameter and the vibration modes are calculated by finite elements analysis. Other sources of error, such as noise and thermal drift, are carefully handled. To reduce noise, the interferometer including cables and digitizers are carefully shielded and grounded. The phase error due to source frequency thermal drift, manifested due to uneven probe beam and reference beam path lengths, is observed in long term operation and explained by model calculation. A continuous 100 s test shows that it is reduced to about 0.04 °/s when the Gunn oscillators are temperature controlled by Peltier coolers with the industrial Proportional-Integral-Derivative control method to maintain the frequency stability. The system has been in routine operation since August 2019, with 1016 m-2 line-integral density resolution. The technical details of the interferometer and experimental results are presented.

T08010

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We describe the use of machine learning algorithms to select high-quality measurements for the Mu2e experiment. This technique is important for experiments with backgrounds that arise due to measurement errors. The algorithms use multiple pieces of ancillary information that are sensitive to measurement quality to separate high-quality and low-quality measurements.

T08009

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JUNO is a 20-kton liquid scintillator detector aiming to determine the neutrino mass ordering, precisely measure the oscillation parameters, detect the astrophysical neutrinos and search for exotic physics. It is designed to reach an energy resolution of 3% at 1 MeV with the highest ever PMT coverage, using two types of 20" phototubes: MCP-PMT from NNVT and dynode-PMT from Hamamatsu. In this article, the gain and charge response of the MCP and dynode PMTs are investigated with the study of JUNO Central Detector prototype. The linearity of the MCP-PMT charge output is measured too to check the effect of a long tail on its charge spectrum.

T08008

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This paper describes the design and construction of the automatic calibration unit (ACU) for the JUNO experiment. The ACU is a fully automated mechanical system. It is capable of deploying multiple radioactive sources, an ultraviolet (UV) laser source, or an auxiliary sensor such as a temperature sensor, one at a time, into the central detector of JUNO along the central axis. It is designed as a primary tool to precisely calibrate the energy scale of detector, aligning timing for the photosensors, and partially monitoring the position-dependent energy scale variations.

T08007

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Gamma sources are routinely used to calibrate the energy scale and resolution of liquid scintillator detectors. However, non-scintillating material surrounding the source introduces energy losses, which may bias the determination of the centroid and width of the full absorption peak. In this paper, we present a general method to determine the true gamma centroid and width to a relative precision of 0.03% and 0.50%, respectively, using energy losses predicted by the Monte Carlo simulation. In particular, the accuracy of the assumed source geometry is readily obtained from the fit. The method performs well with experimental data in the Daya Bay detector.

T08006

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This paper describes the use of a set of small cosmic ray detectors for the measurement of the decoherence curve, i.e. the probability of observing coincidence events between pairs of particles from an extensive air shower as a function of the separation distance between them. Individual detection modules were arranged into 15 telescopes located in various positions, such as to cover nominal separation distances between 0.5 and about 25 m with a fine mesh. A measurement of the decoherence curve has been carried out during a period of approximately 24 days at an altitude close to the sea level, with the detectors located in a large lecture hall of the Physics Department, below a concrete roof. Results were also compared to theoretical simulations of extensive air showers based on Corsika. Performance of the method is discussed, with possible extension of this technique to provide a low-cost facility for the investigation of the decoherence curve at even larger distances.

T08005

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One of the applications of single-photon emission computed tomography (SPECT) and positron emission tomography (PET) is myocardial imaging. Myocardial perfusion imaging with PET (MPI-PET) is gradually becoming an alternative to MPI-SPECT due to its higher image quality. Although Rb-82 is the most common tracer for MPI-PET, Rb-82 emits high-energy positrons with a long stopping range, resulting in blurring of the spatial resolution of the PET image. Due to the limitations of spatial resolution, imaging of Rb-82 in mice has not been reported. In this study, we propose a new method to achieve higher resolution imaging of Rb-82 in small animals than possible with PET imaging by detecting bremsstrahlung X-rays emitted by the positrons, and we validated the feasibility of this method using Monte Carlo simulation. We simulated a small field of view (FOV) pinhole X-ray camera based on a thin YAlO3:Ce (YAP(Ce)) plate and analyzed the basic performance of the simulated camera for bremsstrahlung X-rays. The spatial resolution of a 0.5 mm-thick YAP(Ce) plate-based camera with a 1.0 mm pinhole collimator was 2.6 mm full width at half maximum (FWHM) at a distance of 17.5 mm from the surface of the collimator. Furthermore, we simulated imaging of a mouse heart phantom filled with Rb-82 of 67 MBq per milliliter. We observed the shape of the phantom in the image for a 10 - 45 keV energy window in a simulated measurement time of 4 minutes. We conclude that imaging of high-energy positron emitters at a higher resolution than by PET imaging is possible through detection of the bremsstrahlung X-rays emitted from the positrons.

T08004
The following article is Open access

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Binned maximum likelihood fits are an attractive option when analysing large datasets, but require care when computing likelihoods of continuous PDFs in bins. For many years the widely used statistical modelling package evaluated probabilities at the bin centre, leading to significant biases for strongly curved probability density functions. We demonstrate the biases with real-world examples, and introduce a PDF class to that removes these biases. The physics and computation performance of this new class are discussed.

T08003

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This paper presents the design and evaluation of a portable γ spectrometer with an automatic constant temperature function. The γ spectrometer includes a detector consisting of a CsI(Na) crystal coupled with a silicon photomultiplier (SiPM) array and highly integrated readout electronics. The performance of the crystal and SiPM changes with temperature. To solve this problem, we design a thermoelectric cooler-based unit to keep the temperature constant. Experiments are conducted to evaluate the performance of the γ spectrometer under different temperatures. The test results show that when the external temperature range is 2–38 °C, the temperature inside the spectrometer remains constant at 20 ± 0.07 °C. Because of the constant temperature, the peak drift for 662   keV is reduced to 1.80 channels, and the energy resolution for 662   keV remains around 8.20%.

T08002

, , , , , , , , , et al

A nitrogen purification pilot plant has been developed to meet the requirements of high purity nitrogen used in the Jiangmen Underground Neutrino Observatory (JUNO). The radon content in nitrogen dropped from (20.5 ± 0.9) mBq/Nm3 (statistical error) to (25.2 ± 4.5) μBq/Nm3 (stat.) after purification. The Rn reduction factor of the nitrogen purification pilot plant was estimated to be 813 under the condition of 20 mBq/Nm3 of radon activity. Another experimental result showed that the radon activity dropped from (61.6 ± 7.5) μBq/Nm3 (stat.) to (19.2 ± 2.1) μBq/Nm3 (stat.) after nitrogen flew out from the nitrogen purification pilot plant. It shows that the radon activity of nitrogen after purified by the nitrogen purification pilot plant meets the cleanliness requirement of JUNO and the Rn reduction factor of the nitrogen purification pilot plant would decline when the radon activity of raw nitrogen declines to dozens of μBq/Nm3.

T08001

, , , , , , , , , et al

The main goal of the JUNO experiment is the determination of the neutrino mass ordering. To achieve this, an extraordinary energy resolution of at least 3 % at 1 MeV is required for which all parts of the JUNO detector need to meet certain quality criteria. This is relevant in particular for those which are related to the energy resolution of the detector, such as the photomultiplier tubes (PMTs) to be deployed in JUNO. This paper presents the setup and performance of a dedicated PMT mass testing facility to examine and characterize the performance of the 20-inch JUNO PMTs. Its quasi-industrial size and operation level allows to test all 20000 PMTs intended to be used in the JUNO experiment. With this PMT mass testing system, several key characteristics like dark count rate, peak-to-valley ratio, photon detection efficiency, and timing resolution have been determined at an operating gain of 1 × 107 and assessed with respect to the requirements of JUNO. Measurement conditions and modes for the PMTs as well as estimated accuracies for the determination of the individual PMT parameters with the system are presented as well.

Erratum

E08001
The following article is Open access

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Many of the modern concrete structures such as sea-links and bridges are built in water. They require structural health monitoring (SHM) and audit to ascertain the quality and estimation of remaining useful life. To meet these requirements, a single-channel ultrasonic imaging system has been designed and developed to detect defects, porosities and rebar locations inside the Concrete/ Reinforced Cement Concrete (RCC) structures. This real-time and reconfigurable embedded system was evaluated by carrying out under-water imaging of Concrete and RCC test blocks. Conventionally, Ultrasonic Pulse Velocity (UPV) method is being utilized over three decades in Transmit-Receive (T-R) mode to estimate the density and strength of the concrete structure under test. UPV method requires a skill to interpret the data provided by the UPV instrument. The novelty of the single-channel system discussed in this paper is that it is capable of inspecting Concrete/ RCC structures both in Pulse Echo (PE) as well as in T-R mode. An application software has been developed using C# in a visual environment for image acquisition and the control of Data Acquisition (DAQ) hardware has been interfaced to the computer via USB. The imaging system performs data acquisition and coherent averaging of the RF bipolar data to achieve Signal-to-Noise Ratio (SNR) higher than 20 dB. The performance of the system was evaluated by acquiring B-Scan images of the water submerged concrete test blocks having Side Drilled Hole (SDH) and RCC blocks with one as well as two steel rebars, using 54 kHz water immersion transducer in PE mode. The acquired B-Scan images have revealed the internal details of the sample test blocks, resembling the defects generated in the test blocks. High voltage tone burst bipolar pulser with maximum output of (±350 V) has been specifically designed for this system to inspect highly attenuative porous and non-homogeneous Concrete/ RCC materials for the detection of SDH and reinforced steel bars in the concrete test blocks, using B-Scan imaging technique.