The ability of a statistical method to reproduce data of any physical quantity with high precision gives the pattern for the prediction of out of the range data. Prediction procedures of significant physical quantities represent a useful... more
The ability of a statistical method to reproduce data of any physical quantity with high precision gives the pattern for the prediction of out of the range data. Prediction procedures of significant physical quantities represent a useful tool in drawing inferences about the behaivor of the outofthe range data and so, about the generator events. Theoretical predictions out of the
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The Pre-Damping Rings (PDRs) and Damping Rings (DRs) of CLIC are needed to reduce the beam emittances to the small values required for the main linacs. The injection and extraction, from the PDRs and DRs, are carried out by kicker... more
The Pre-Damping Rings (PDRs) and Damping Rings (DRs) of CLIC are needed to reduce the beam emittances to the small values required for the main linacs. The injection and extraction, from the PDRs and DRs, are carried out by kicker systems. In order to achieve both low beam coupling impedance and reasonable broadband impedance matching to the electrical circuit, striplines have been chosen for the kicker elements. The design of the stripline kicker was pre-viously carried out by modelling the striplines with simula-tion codes such as HFSS, Quickfield and CST Particle Stu-dio. In order to have a complete analysis of the striplines, the effect of electrode supports and coaxial feedthroughs have been studied in detail. In this paper, electromag-netic analyses of the complete striplines, including fabri-cation tolerances, are reported. Furthermore, a new idea for impedance matching is presented.
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The PRAE project (Platform for Research and Applications with Electrons) aims at creating a multidisciplinary R&D facility in the Orsay campus gathering various scientific communities involved in radiobiology, subatomic physics,... more
The PRAE project (Platform for Research and Applications with Electrons) aims at creating a multidisciplinary R&D facility in the Orsay campus gathering various scientific communities involved in radiobiology, subatomic physics, instrumentation and particle accelerators around an electron accelerator delivering a high-performance beam with energy up to 70 MeV and later 140 MeV, in order to perform a series of unique measurements and future challenging R&D. In this paper we report the first start-to-end simulations from the RF gun, going through the linac and finally to the different experimental platforms. The beam dynamics simulations have been performed using a concatenation of codes. In particular for the linac the RF-Track code recently developed at CERN will be used and benchmarked. The different working points have been analysed in order to minimise the transverse emittance and the beam energy spread including space charge effects at low electron energies.
Precise and fast beam size measurement and emittance reconstruction in the different subsystems and transfer lines of the Future Linear Colliders (ILC and CLIC) will be essential for beam tuning in order to achieve the required... more
Precise and fast beam size measurement and emittance reconstruction in the different subsystems and transfer lines of the Future Linear Colliders (ILC and CLIC) will be essential for beam tuning in order to achieve the required luminosity. In this paper we investigate the feasibility of using a multi-Optical Transition Radiation (m-OTR) system for fast transverse beam size measurement, emittance reconstruction and coupling correction in the Ring to Main Linac (RTML) of the FLCs. Diagnostic sections of the RTML have been matched to the optimum optical conditions for emittance reconstruction. The necessary requirements for the OTR monitors to be placed in the RTML are discussed.
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The proposed CERN FCC-hh proton-proton collider will operate at unprecedented per-particle (50 TeV) and total stored beam energies (8.4 GJ). These high energies create the requirement for an efficient collimation system in order to... more
The proposed CERN FCC-hh proton-proton collider will operate at unprecedented per-particle (50 TeV) and total stored beam energies (8.4 GJ). These high energies create the requirement for an efficient collimation system in order to protect the accelerator components and experiments. In order to verify the performance of proposed collimation system designs, loss map simulations have been performed using the code Merlin. Results for the current baseline layout are presented for both betatron and off-momentum loss maps.
High performance collimation systems are required for current and proposed high energy hadron accelerators in order to protect superconducting magnets and experiments. In order to ensure that the collimation system designs are sufficient... more
High performance collimation systems are required for current and proposed high energy hadron accelerators in order to protect superconducting magnets and experiments. In order to ensure that the collimation system designs are sufficient and will operate as expected, precision simulation tools are required. This paper discusses the current status of existing collimation system tools, and performs a comparison between codes in order to ensure that the simulated interaction physics between a proton and a collimator jaw is accurate.
The Accelerator Test Facility 2 (ATF2) at KEK is a prototype of the final focus system for the next generation of Future Linear Colliders(FCL). It aims to focus the beams to tens of nanometer transverse sizes and to provide stability at... more
The Accelerator Test Facility 2 (ATF2) at KEK is a prototype of the final focus system for the next generation of Future Linear Colliders(FCL). It aims to focus the beams to tens of nanometer transverse sizes and to provide stability at the few nm level. Achieving these goals requires modelling, measuring and suppressing of the transverse beam halo before the interaction point (IP). This paper presents a beam tail/halo generator based on realistic model and the investigation of vertical and horizontal beam tail/halo distribution at ATF2.
The H₂020 CompactLight Project (www. CompactLight.eu) aims at designing the next generation of compact X-rays Free-Electron Lasers, relying on very high gradient accelerating structures (X-band, 12 GHz), the most advanced concepts for... more
The H₂020 CompactLight Project (www. CompactLight.eu) aims at designing the next generation of compact X-rays Free-Electron Lasers, relying on very high gradient accelerating structures (X-band, 12 GHz), the most advanced concepts for bright electron photo injectors, and innovative compact short-period undulators. Compared to existing facilities, the proposed facility will benefit from a lower electron beam energy, due to the enhanced undulators performance, and will be significantly more compact, with a smaller footprint, as a consequence of the lower energy and the high-gradient X-band structures. In addition, the whole infrastructure will also have a lower electrical power demand as well as lower construction and running costs.
In order to reduce the background that could limit the precision of the diagnostics located in the ATF2 post-IP beamline a single vertical beam halo collimation system was installed and commissioned in March 2016. In this paper, we... more
In order to reduce the background that could limit the precision of the diagnostics located in the ATF2 post-IP beamline a single vertical beam halo collimation system was installed and commissioned in March 2016. In this paper, we present the measurements done in March and May 2016 in order to characterize the collimation system performance. Furthermore, the collimator wakefield impact has been measured and compared with theoretical calculations and numerical simulations in order to determine the most efficient operation mode of the collimation system in terms of halo cleaning and negligible wakefield impact.
Recent developments on the CLIC collimation and final focus are described. The combination of a shortened linear, or alternative nonlinear, collimation section and a compact final focus substantially reduces the overall system length at 3... more
Recent developments on the CLIC collimation and final focus are described. The combination of a shortened linear, or alternative nonlinear, collimation section and a compact final focus substantially reduces the overall system length at 3 TeV centre-or-mass energy to less than 3 km. A beam-delivery system (BDS) for 500 GeV centre-of-mass energy is obtained by relatively minor optics modifications of the 3-TeV system . It promises a satisfactory performance. The attainable luminosity can be raised, at both energies, by decreasing the beta functions at the collision point. We also discuss field errors, gas scattering and wake fields in the final quadrupoles, and the collimation parameters.
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We review the present design for the CLIC beam delivery system as configured for 3 TeV and for 500 GeV, describe some recent developments (including the combined effect of solenoid, crab cavity, and crossing angle), highlight open... more
We review the present design for the CLIC beam delivery system as configured for 3 TeV and for 500 GeV, describe some recent developments (including the combined effect of solenoid, crab cavity, and crossing angle), highlight open questions, and outline future studies.
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The Platform for Research and Applications with Electrons (PRAE) is a multidisciplinary R&D facility gathering subatomic physics, instrumentation, radiobiology and clinical research around a high-performance electron accelerator with beam... more
The Platform for Research and Applications with Electrons (PRAE) is a multidisciplinary R&D facility gathering subatomic physics, instrumentation, radiobiology and clinical research around a high-performance electron accelerator with beam energies up to 70 MeV. In this paper we report the complete optics design and performance evaluation of a Very High Energy Electron (VHEE) innovative radiobiology study, in particular by using Grid mini-beam and FLASH methodologies, which could represent a major breakthrough in Radiation Therapy (RT) treatment modality.
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The Pre-Damping Rings (PDRs) and Damping Rings (DRs) of CLIC are required to reduce the beam emittances to the small values required for the main linacs. The injection and extraction, from the PDRs and DRs, are performed by kicker... more
The Pre-Damping Rings (PDRs) and Damping Rings (DRs) of CLIC are required to reduce the beam emittances to the small values required for the main linacs. The injection and extraction, from the PDRs and DRs, are performed by kicker systems. To achieve both low beam coupling impedance and reasonable broadband impedance matching to the electrical circuit, striplines have been chosen for the kicker elements. Prototype striplines have been built: tests and measurements of these striplines have started. The goal of these tests is to characterize, without beam, the electro-magnetic response of the striplines. The tests have been carried out at CERN. To study the signal transmission through the striplines, the measured S-parameters have been com-pared with simulations. In addition, measurements of longitudinal beam coupling impedance, using the coaxial wire method, are reported and compared with simulations.
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In this paper we review the status of the studies on nonlinear collimation schemes for the LHC. Concretely we describe the design of a nonlinear optics for betatron clean- ing in IR7. The aim is to investigate alternative nonlinear... more
In this paper we review the status of the studies on nonlinear collimation schemes for the LHC. Concretely we describe the design of a nonlinear optics for betatron clean- ing in IR7. The aim is to investigate alternative nonlinear collimation systems to reduce the collimator-induced impedance that may limit the beam intensity towards the LHC luminosity upgrade. The performance of the LHC nonlinear collimation system is studied by means of tracking simulations and compared with the present LHC system. Furthermore, the advantages and possible limitations of such nonlinear collimation scheme are discussed.
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The International Large Detector (ILD) is a concept for a detector at the International Linear Collider, ILC. The ILC will collide electrons and positrons at energies of initially 500 GeV, upgradeable to 1 TeV. The ILC has an ambitious... more
The International Large Detector (ILD) is a concept for a detector at the International Linear Collider, ILC. The ILC will collide electrons and positrons at energies of initially 500 GeV, upgradeable to 1 TeV. The ILC has an ambitious physics program, which will extend and complement that of the Large Hadron Collider (LHC). The ILC physics case has been well
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Abstract: The CLIC damping rings will produce ultra-low emittance beam, with high bunch charge, necessary for the luminosity performance of the collider. To limit the beam emittance blow-up due to oscillations, the pulse power modulators... more
Abstract: The CLIC damping rings will produce ultra-low emittance beam, with high bunch charge, necessary for the luminosity performance of the collider. To limit the beam emittance blow-up due to oscillations, the pulse power modulators for the damping ring kickers must ...
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Performance limiting high-power rf phenomenon occur in both transmitter systems in satellites and high-gradient accelerating structures in particle accelerators. In satellites the predominant effect is multipactor while in accelerators it... more
Performance limiting high-power rf phenomenon occur in both transmitter systems in satellites and high-gradient accelerating structures in particle accelerators. In satellites the predominant effect is multipactor while in accelerators it is breakdown. Both communities ...
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The document summarizes the recent papers, presentations and other public information on Radio-Frequency (RF) Linear Accelerators (linacs) and Fixed-Field Alternating-Gradient (FFAG) accelerators for hadron therapy. The main focus is on... more
The document summarizes the recent papers, presentations and other public information on Radio-Frequency (RF) Linear Accelerators (linacs) and Fixed-Field Alternating-Gradient (FFAG) accelerators for hadron therapy. The main focus is on technical aspects of these accelerators. This report intends to provide a general overview of the state-of-the-art in those accelerators which could be used in short and middle-term for treating cancer.
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The FCC-ee could measure the electron Yukawa coupling in a dedicated run at $$\sim $$ ∼ 125 GeV collision energy, provided that the center-of-mass (CM) energy spread can be reduced by means of monochromatization, e.g., through introducing... more
The FCC-ee could measure the electron Yukawa coupling in a dedicated run at $$\sim $$ ∼ 125 GeV collision energy, provided that the center-of-mass (CM) energy spread can be reduced by means of monochromatization, e.g., through introducing nonzero horizontal dispersion of opposite sign at the interaction point (IP), for the two colliding beams. If the IP dispersion is nonzero, beamstrahlung blows up the horizontal emittance, and self-consistent IP parameters need to be determined. Two configurations are being studied. The first uses crab cavities to establish effective head-on collisions. The second configuration maintains the standard FCC-ee crossing angle, which, together with the IP dispersion, introduces a correlation between the local collision energy and the longitudinal location inside the detector, thereby allowing for an integrated scan of the Higgs resonance curve. We compare both approaches.
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A set of 16 Inductive Pick-Ups (IPU) for Beam Position Monitoring (BPM) with its associated electronics were designed, constructed and characterized at IFIC for the Test Beam Line (TBL) of the 3rd CLIC Test Facility (CTF3) at CERN. In... more
A set of 16 Inductive Pick-Ups (IPU) for Beam Position Monitoring (BPM) with its associated electronics were designed, constructed and characterized at IFIC for the Test Beam Line (TBL) of the 3rd CLIC Test Facility (CTF3) at CERN. In October 2009 the full set of IPUs, (BPS) was successfully installed in the TBL line. In this paper, we describe the prototyping and series production phases of the BPSs development, focusing in the implementation and the results analysis derived from their characterization tests. Two special test benches were designed and built to perform the characterization tests at low and high frequencies. The low frequency set up based on a wire-method test bench for emulating the beam position variations helped us to determine the BPS performance parameters at beam pulse time scale from 100μs/10kHz to 10ns/100MHz. On the other hand, the high frequency test setup, based on an adapted coaxial transmission line, was dedicated to obtain the BPS longitudinal coupling ...
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The international Future Circular Collider (FCC) study is designing hadron, lepton and lepton-hadron colliders based on a new 100 km tunnel in the Geneva region. The main focus and ultimate goal of the study are high-luminosity... more
The international Future Circular Collider (FCC) study is designing hadron, lepton and lepton-hadron colliders based on a new 100 km tunnel in the Geneva region. The main focus and ultimate goal of the study are high-luminosity proton-proton collisions at a centre-of-mass energy of 100 TeV, using 16 T Nb3Sn dipole magnets. Specific FCC beam dynamics issues are related to the large circumference, the high brightness - made available by radiation damping -, the small geometric emittance, unprecedented collision energy and luminosity, the huge amount of energy stored in the beam, large synchrotron radiation power, plus the injection scenarios. In addition to the FCC-hh proper, also a High-Energy LHC (HE-LHC) is being explored, using the FCC-hh magnet technology in the existing LHC tunnel, which can yield a centre-of-mass energy around 25 TeV.
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The Accelerator Test Facility 2 (ATF2) at KEK is a prototype for the Final Focus Systems of the future e+elinear colliders, the International Linear Collider (ILC) and the Compact Linear Collider (CLIC). In this paper both simulation and... more
The Accelerator Test Facility 2 (ATF2) at KEK is a prototype for the Final Focus Systems of the future e+elinear colliders, the International Linear Collider (ILC) and the Compact Linear Collider (CLIC). In this paper both simulation and experimental results are presented with special emphasis on intensity-dependent effects. The importance of these effects is shown using the PLACET code and realistic ATF2 machine simulations (including beam jitter, misalignment, wakefield, Beam Based Alignment (BBA) correction). The latest experimental results are also presented, in particular the impact of the beam intensity on the beam size at the IP.
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Beam Position Monitors (BPM) are essential elements in the instrumentation for the beam control in Hadronther-apy accelerators. The measurement of the beam position become more important at the secondary transport lines to-wards the... more
Beam Position Monitors (BPM) are essential elements in the instrumentation for the beam control in Hadronther-apy accelerators. The measurement of the beam position become more important at the secondary transport lines to-wards the patient room where this parameter must be com-pletely determined. In this paper we describe the design, construction, read-out electronics and first calibration tests of a 1st protptype of a BPM based on four scintillating fibers coupled to four photodiodes to detect the light pro-duced by the fibers when intercepting the beam tails. The prototype will serve to evaluate the different design options in the mechanical and the read-out electronics implementa-tion as well as to define the best processing method to get the beam position.
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The CLIC Test Facility (CTF3) at CERN was constructed by the CTF3 collaboration to study the feasibility of the concepts for a compact linear collider. The test beam line (TBL) recently added to the CTF3 machine was designed to study the... more
The CLIC Test Facility (CTF3) at CERN was constructed by the CTF3 collaboration to study the feasibility of the concepts for a compact linear collider. The test beam line (TBL) recently added to the CTF3 machine was designed to study the CLIC decelerator beam dynamics and 12 GHz power production. The beam line consists of a FODO lattice with high
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A prototype of a stripline Beam Position Monitor (BPM) with its associated readout electronics has been developed at CERN in collaboration with SLAC, LAPP and IFIC. In this paper, the design and simulations of the BPM with the analog... more
A prototype of a stripline Beam Position Monitor (BPM) with its associated readout electronics has been developed at CERN in collaboration with SLAC, LAPP and IFIC. In this paper, the design and simulations of the BPM with the analog readout chain and the BPM test bench are described, and the results of the first characterization tests are presented. The position
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Nonlinear fields arising from eddy currents in the vac-uum chamber and remanent fields in the magnets of the CERN SPS vary with time and with the acceleration cycle. We describe a procedure of constructing a nonlinear op-tics model for... more
Nonlinear fields arising from eddy currents in the vac-uum chamber and remanent fields in the magnets of the CERN SPS vary with time and with the acceleration cycle. We describe a procedure of constructing a nonlinear op-tics model for the SPS, by considering sextupolar, octupo-lar, and decapolar field errors in the dipole and quadrupole magnets, respectively, whose strengths are adjusted
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Since several years, the vertical beam emittance measured in the Extraction Line (EXT) of the Accelerator Test Facility (ATF) at KEK, that will transport the electron beam from the ATF Damping Ring (DR) to the future ATF2 Final Focus beam... more
Since several years, the vertical beam emittance measured in the Extraction Line (EXT) of the Accelerator Test Facility (ATF) at KEK, that will transport the electron beam from the ATF Damping Ring (DR) to the future ATF2 Final Focus beam line, is significantly larger than the emittance measured in the DR itself, and there are indications that it grows rapidly