The Spallation Neutron Source (SNS), currently under construction at Oak Ridge, Tennessee, is a collaborative effort between six U.S. Department of Energy partner laboratories. Brookhaven National Laboratory (BNL) is responsible for the... more
The Spallation Neutron Source (SNS), currently under construction at Oak Ridge, Tennessee, is a collaborative effort between six U.S. Department of Energy partner laboratories. Brookhaven National Laboratory (BNL) is responsible for the ring and transport lines requiring 312 magnets and 251 power supplies. The challenge is to maintain a closed communication loop among stakeholders for the variable parameters integral to these two major systems. This paper provides an overview of the organization and functional responsibilities used to define, update and communicate specific design parameters related to the SNS magnet, power supply, and other critical systems. Figure 1: Schematic of the SNS Accumulator Complex
The Soft Inelastic X-ray scattering (SIX) and the Electron-Spectro-Microscopy (ESM) are two beamlines under construction at National Synchrotron Light Source-II (NSLS-II). The specifics of these two beamlines required the use of two long... more
The Soft Inelastic X-ray scattering (SIX) and the Electron-Spectro-Microscopy (ESM) are two beamlines under construction at National Synchrotron Light Source-II (NSLS-II). The specifics of these two beamlines required the use of two long Advanced Planar Polarized Light Emitter-II (APPLE-II) undulators, as a source that provides both circularly and vertically polarized radiation. Thus, we designed 3.5 m and 2.7m long APPLE-II type undulators for SIX and ESM. The NSLS-II ID group is responsible for the magnetic optimization of these two long undulators. In this paper, we first summarize the APPLE-II magnetic and mechanical design. Then, we discuss the magnetic performance of the first APPLE-II achieved with the shimming performed at BNL.
The purpose of this study was to determine the effect of beam mis-steering, on the temperature of the vacuum chamber. The chamber used for this study was for the Coherent Soft X-Ray (CSX) Elliptically Polarizing Undulator (EPU). Finite... more
The purpose of this study was to determine the effect of beam mis-steering, on the temperature of the vacuum chamber. The chamber used for this study was for the Coherent Soft X-Ray (CSX) Elliptically Polarizing Undulator (EPU). Finite Element Analysis was conducted on the vacuum chamber to determine the temperature distribution on the chamber for set values of beam missteer, for NSLS-II. These results were then compared with on-site temperature measurements taken using RTD’s, as well as thermal sensitive cameras. The accuracy of these results was analyzed and further FEA studies were proposed for steeper beam mis-steers and beam offsets. INTRODUCTION The Coherent Soft X-Ray (CSX) Elliptical Polar Undulator (EPU) beam line has two EPU’s at a canted angle of 0.16 mrad. The effect of synchrotron radiation of the upstream device was studied on the vacuum chamber downstream. A single vacuum chamber made of Aluminum, as indicated in Fig. 1, covers the entire length of both the EPU’s. The...
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Both In-Vacuum Undulators (IVU) and Cryogenic Permanent Magnet Undulators (CPMU), each important to third generation light sources, are best characterized in their operating environment. To create a precision field map of an IVU/CPMU (IVU... more
Both In-Vacuum Undulators (IVU) and Cryogenic Permanent Magnet Undulators (CPMU), each important to third generation light sources, are best characterized in their operating environment. To create a precision field map of an IVU/CPMU (IVU hereafter), an In-Vacuum Magnetic Measurement (IVMM) System is proposed. Point-by-point measurement of field and trajectory error informs corrective tuning. A novel design concept for a universal IVMM System has been developed and explored. The IVMM seals to the rectangular UHV-flange of the IVU and shares its common vacuum space. Moreover, a modular design permits a wide range of IVU of varying magnetic length to be mapped with a single IVMM, and is thus cost effective when multiple IVU of varying configurations are planned. Here we review aspects of the modular IVMM design concept.
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Both in-vacuum undulators (IVUs) and cryogenic permanent magnet undulators (CPMUs), each important to third-generation light sources, are best characterized in their operating environment. To create a precision Hall probe map of an... more
Both in-vacuum undulators (IVUs) and cryogenic permanent magnet undulators (CPMUs), each important to third-generation light sources, are best characterized in their operating environment. To create a precision Hall probe map of an IVU/CPMU (IVU hereafter), an in-vacuum magnetic measurement (IVMM) system is proposed. Point-by-point measurement of field and trajectory error informs corrective tuning.A novel design concept for a universal IVMM System has been developed and explored. The IVMM seals to the rectangular Ultra High Vacuum (UHV) flange of the IVU and shares its common vacuum space. Moreover, a modular design permits a wide range of IVUs of varying magnetic length to be mapped with a single IVMM, and is thus cost effective when multiple IVUs of varying configurations are planned. Here we review aspects of the modular IVMM design concept.
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National Synchrotron Light Source-II (NSLS-II) is the latest storage ring of 3 GeV energy at the Brookhaven National Laboratory (BNL). The horizontal emittance of the electron beam with the currently installed six damping wigglers is... more
National Synchrotron Light Source-II (NSLS-II) is the latest storage ring of 3 GeV energy at the Brookhaven National Laboratory (BNL). The horizontal emittance of the electron beam with the currently installed six damping wigglers is 0.9 nm.rad, which could be further reduced to 0.5 nm.rad with more insertion devices (IDs). With only one RF cavity the beam current is restricted to 200 mA. Five hundred mA operation is envisaged for next year with an addition of the second cavity. Six (plus two branches) beamlines have been commissioned in the initial phase of the project. In July 2015, three NIH funded beamlines called “Advanced Beamlines for Biological Investigations with X-rays” (ABBIX) will be added for operation. This paper describes the experiences of ID development, installation, and commissioning for the NSLS-II project as well as our future plans to improve the performance of the facility in terms of source development.
MECHANICAL AND THERMAL CONSIDERATIONS FOR THE SUPERCONDUCTING MAGNET TO NORMAL CONDUCTOR MAGNET" WARM-TO-COLD TRANSITIONS" OF THE RHIC ACCELERATOR James Rank, Ken Malm, Gary Mclntyre, and John Sondericker Relativistic Heavy Ion... more
MECHANICAL AND THERMAL CONSIDERATIONS FOR THE SUPERCONDUCTING MAGNET TO NORMAL CONDUCTOR MAGNET" WARM-TO-COLD TRANSITIONS" OF THE RHIC ACCELERATOR James Rank, Ken Malm, Gary Mclntyre, and John Sondericker Relativistic Heavy Ion ...
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The installation and testing of most of the Relativistic Heavy Ion Collider (RHIC) cryogenic system is complete. The RHIC cryogenic system consisting of the modified ISABELLE refrigerator, and other new cryogenic components, has been... more
The installation and testing of most of the Relativistic Heavy Ion Collider (RHIC) cryogenic system is complete. The RHIC cryogenic system consisting of the modified ISABELLE refrigerator, and other new cryogenic components, has been completed from the 25 kW refrigerator through one sixth of the 3.8 km circumference RHIC accelerator up to the 4:00 valve box. This paper covers the progress to date with respect to construction and installation of the helium distribution system, including the vacuum jacketed piping and valve boxes, recoolers, and controls. In addition, the 25 kW refrigerator has been operated on three seChapaute occasions over the past two years. These first experiences with the operation of the refrigerator and warm compressor system, along with some test results will be discussed here.
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National Synchrotron Light Source-II (NSLS-II) project is now in the construction stage. A new insertion device (ID) magnetic measurement facility (MMF) is being set up at Brookhaven National Laboratory in order to satisfy the stringent... more
National Synchrotron Light Source-II (NSLS-II) project is now in the construction stage. A new insertion device (ID) magnetic measurement facility (MMF) is being set up at Brookhaven National Laboratory in order to satisfy the stringent requirement on the magnetic field measurement of IDs. ISO-Class7 temperature stabilized clean room is being constructed for this purpose. A state-of-the-art Hall probe bench and
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... Coil, pole and yoke design calculations and electromagnetics optimization are presented. Rank, Jim; McGahern, William J; Miglionico, Gary; Raparia, Deepak; Tsoupas, Nicholaos; Tuozzolo, Joseph; Wei, Jie; Yung Lee, Yong. Skip to main... more
... Coil, pole and yoke design calculations and electromagnetics optimization are presented. Rank, Jim; McGahern, William J; Miglionico, Gary; Raparia, Deepak; Tsoupas, Nicholaos; Tuozzolo, Joseph; Wei, Jie; Yung Lee, Yong. Skip to main content. ...
MECHANICAL AND THERMAL CONSIDERATIONS FOR THE SUPERCONDUCTING MAGNET TO NORMAL CONDUCTOR MAGNET" WARM-TO-COLD TRANSITIONS" OF THE RHIC ACCELERATOR James Rank, Ken Malm, Gary Mclntyre, and John Sondericker Relativistic Heavy Ion... more
MECHANICAL AND THERMAL CONSIDERATIONS FOR THE SUPERCONDUCTING MAGNET TO NORMAL CONDUCTOR MAGNET" WARM-TO-COLD TRANSITIONS" OF THE RHIC ACCELERATOR James Rank, Ken Malm, Gary Mclntyre, and John Sondericker Relativistic Heavy Ion ...
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National Synchrotron Light Source-II (NSLS-II) project is currently under construction. Procurement of various insertion devices (IDs) has begun. This ring assumes a very high beam stability requirement which imposes tighter field... more
National Synchrotron Light Source-II (NSLS-II) project is currently under construction. Procurement of various insertion devices (IDs) has begun. This ring assumes a very high beam stability requirement which imposes tighter field specifications on insertion devices (IDs) compared to the rings of previous generation. The state of the art ID Magnetic Measurement Facility is being set up in order to be able to certify the stringent requirements on the magnetic field of NSLS-II IDs. The IDs in the project baseline scope include six 3.5m long damping wigglers (DWs) with 100mm period length and 15mm pole gap, two 2.0m Elliptically Polarizing Undulator (EPU) with 49mm period and 11.5mm minimum magnetic gap, two 3.0m long 20mm period and one 1.5m long 21mm period IVU, which the minimum gap of these is 5mm and 5.5mm, respectively. Recently a special device for inelastic X-ray scattering (IXS) beamline has been added to the collection of baseline devices. Three pole wigglers with a 28mm magn...
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In this paper we explore the possibility of using diamond secondary emitter in a high average current electron injector to amplify the current from the photocathode and to isolate the cathode and the injector from each other to increase... more
In this paper we explore the possibility of using diamond secondary emitter in a high average current electron injector to amplify the current from the photocathode and to isolate the cathode and the injector from each other to increase the life time of the cathode and preserve the performance of the injector. Secondary electron yield of 225 and current density
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ABSTRACT Short period (14.5mm) hybrid undulator arrays composed of Praseodymium Iron Boron (Pr2Fe14B) magnets (CR53, NEOMAX, Inc.) and vanadium permendur poles have been fabricated at Brookhaven National Laboratory. Unlike Neodymium Iron... more
ABSTRACT Short period (14.5mm) hybrid undulator arrays composed of Praseodymium Iron Boron (Pr2Fe14B) magnets (CR53, NEOMAX, Inc.) and vanadium permendur poles have been fabricated at Brookhaven National Laboratory. Unlike Neodymium Iron Boron (Nd2Fe14B) magnets which exhibit spin reorientation at a temperatures below 150 K, PrFeB arrays monotonically increase performance with lower operating temperature. It opens up the possibility for use in operating a cryo‐permanent magnet undulator (CPMU) in the range of 40 K to 60 K where very efficient cryocoolers are available. Magnetic flux density profiles were measured at various temperature ranges from room temperature down to liquid helium (LHe) using the Vertical Testing Facility (VTF) at the National Synchrotron Light Source‐II (NSLS‐II). Temperature variations of phase error have been characterized. In addition, we examined the use of textured Dysprosium (Dy) poles to replace permendur poles to obtain further improvement in performance.
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An ampere class 20 MeV superconducting Energy Recovery Linac (ERL) is under construction at Brookhaven National Laboratory (BNL) for testing of concepts relevant for high-energy coherent electron cooling and electron-ion colliders. One of... more
An ampere class 20 MeV superconducting Energy Recovery Linac (ERL) is under construction at Brookhaven National Laboratory (BNL) for testing of concepts relevant for high-energy coherent electron cooling and electron-ion colliders. One of the goals is to demonstrate an electron beam with high charge per bunch ( 5 nC) and low normalized emittance ( 5 mm-mrad) at an energy of
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Mechanical vibrations of accelerator components have been studied in the context of various colliders, both existing ones like HERA [1], [2] and [3] or the TEVATRON [4] and [5], and future projects like the Linear Collider [6], [7] and... more
Mechanical vibrations of accelerator components have been studied in the context of various colliders, both existing ones like HERA [1], [2] and [3] or the TEVATRON [4] and [5], and future projects like the Linear Collider [6], [7] and [8]. In each case, there is a serious concern ...
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An integrated helium cryogenic system was designed with the specific performance goal of cooling and refrigerating the cryogenic magnets to below their nominal operating temperature. These magnets make up the steering and focusing... more
An integrated helium cryogenic system was designed with the specific performance goal of cooling and refrigerating the cryogenic magnets to below their nominal operating temperature. These magnets make up the steering and focusing elements for the Relativistic Heavy Ion Collider (RHIC). In addition to meeting the accelerator demands, reliability, flexibility, safety, and ease of operation were key considerations during the
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ABSTRACT The Spallation Neutron Source ring, which is presently being commissioned at Oak Ridge National Laboratory, is designed to accumulate high-intensity protons. Ultrahigh vacuum of 10â»â¹ torr is required in the accumulator ring... more
ABSTRACT The Spallation Neutron Source ring, which is presently being commissioned at Oak Ridge National Laboratory, is designed to accumulate high-intensity protons. Ultrahigh vacuum of 10â»â¹ torr is required in the accumulator ring to minimize beam-residual gas ionization. To reduce the secondary-electron yield and the associated electron cloud instability, the ring vacuum chambers are coated with titanium nitride (TiN). In order to minimize radiation exposure, quick-disconnect chain clamp flanges are used in some areas where radiation levels are expected to be high. This article describes the design, fabrication, assembly, and vacuum processing of the ring and beam transport vacuum systems, as well as the associated vacuum instrumentation.
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The ECX Project, Brookhaven Lab's predecessor to the RHIC e-Cooler, includes a prototype RF tuner mechanism capable of both coarse and fast tuning. This tuner concept, adapted originally from a DESY design, has longer stroke and... more
The ECX Project, Brookhaven Lab's predecessor to the RHIC e-Cooler, includes a prototype RF tuner mechanism capable of both coarse and fast tuning. This tuner concept, adapted originally from a DESY design, has longer stroke and significantly higher loads attributable to the very stiff ECX cavity shape. Structural design, kinematics, controls, thermal and RF issues are discussed and certain improvements