| Paper | Title | Other Keywords | Page |
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| MOPME022 | Beam Commissioning of Two Horizontal Pulse Steering Magnets for Changing Injection Painting Area from MLF to MR in the 3-GeV RCS of J-PARC | injection, stripper, emittance, target | 518 |
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| We have been successfully commissioned two pulse steering magnets installed in the Linac to 3-GeV RCS (Rapid Cycling Synchrotron) injection beam transport (BT) line of J-PARC. RCS has to deliver a simultaneous as well as specific beam as demand by the downstream facilities of MLF (Material and Life Science Facility) and the MR (Main Ring). In order to obtain relatively a smaller transverse emittance at extraction, those magnets were designed to perform a smaller injection painting for the MR beam as compared to the MLF one. As stripper foil position is fixed for the charge exchange H− injection, inclination of the injected beam centroid on foil for the MR beam is only moved to a smaller value by the pulse steering magnets, while DC septum magnets are fixed as determined first for the MLF beam. Their parameters were found to be very consistent with expectation and thus already in operation for switching to a painting area of 100 pi mm mrad for the MR beam as compared to that of 150 pi mm mrad for the MLF beam. | |||
| MOPME026 | Beam Monitor Layout for Future ACS Section in J-PARC Linac | linac, cavity, DTL, monitoring | 529 |
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| In J-PARC Linac, an energy and intensity upgrade project has started since 2009 using Annular Coupled Structure (ACS) cavities. With this upgrade, the design peak current will be increased from the present 30 mA to 50 mA, and the energy from 181 MeV to 400 MeV. Along with these significant upgrades of the beam parameters, beam monitors should be followed. Also, the bunch shape monitor and new beam loss monitoring system will be employed for the new beam line. Newly fabricated devices will be delivered in the ACS beam line. And beam monitor layout of the upstream and downstream of ACS beam line will be modified. In this paper, we introduce the development of the beam diagnostic devices for the project and the new designed beam monitor layout. | |||
| MOPWO070 | Higher Order Symplectic Integration of Collective Effects | collective-effects, simulation, space-charge, wakefield | 1046 |
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| Long time tracking simulations of intense beams requires a proper account for the collective effects. Many tracking codes allow the number of space charge kicks, for example, to be determined by the end user. This makes no guarantee that the integration is second order accurate in the step size. In this proceeding, we present results on the proper second- and fourth-order symplectic integration of the Hamiltonian dynamics of particles under collective interactions using a model Hamiltonian with collective space charge forces to illustrate the underlying principles. | |||
| TUPFI003 | The Accelerator Design of Muon g-2 Experiment at J-PARC | rfq, target, proton, acceleration | 1334 |
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| New muon g-2 experiment at J-PARC is aimed to improve the precise measurement of the muon g-2. In this experiment, the ultra-cold muons created in the muonium target region is reaccelerated to around 300MeV/c in momentum (210 MeV kinetic energy) to then be injected into the muon g-2 storage ring to measure the decay products depending on the muon spin. The linac has advantage over circular accelerators to shorten the reacceleration time in the limited life time of muon. The muon linac consists of the initial acceleration (to 0.01 of v/c), bunching section (0.01 to 0.08 of v/c), low beta section (0.08 to 0.3 of v/c), middle beta section (0.3 to 0.7 of v/c) and high beta section (0.7 to 0.94 of v/c). As a part of the design consideration of this linac, we mainly present the simulation result of initial acceleration and further acceleration of muons with RFQ. An electric field is used to extract the ultra-cold muons from the laser ionization region and RF field is used to create some bunches and to accelerate to higher energies. | |||
| TUPWA068 | Model Independent Beam Tuning | simulation, quadrupole, linac, drift-tube-linac | 1862 |
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| This work presents a new model independent feedback control scheme for optimization and tuning of particle accelerator components, with a simulation demonstrating the method on a low energy, space-charge dominated beam. The scheme presented here does not depend on an accurate model of the system it is stabilizing, and may even be unaware of its control input direction (such as having rotated quadrupole magnets and alignment errors) and this direction may change with time (thermal cycling and hysteresis). Stability properties are demonstrated both analytically and through a simulation in which the current settings of twenty two quadrupole magnets are simultaneously tuned through the transport section of the Los Alamos Linear Proton Accelerator. The controller is unaware of the complex nonlinear beam dynamics, with its only input being the surviving beam current readings along the transport region. Starting with all magnet settings at zero, in which case all of the beam is lost by the end of the transport, the feedback control tunes the magnets resulting in successful transport to the first drift tube linac section. | |||
| TUPWO010 | Optimal Twiss Parameters for Emittance Measurement in Periodic Transport Channels | emittance, betatron, simulation, focusing | 1898 |
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From the point of view of the optimality criteria introduced in *, we study in this paper the procedure of emittance measurement in periodic beam transport channels.
* V.Balandin, W.Decking, N.Golubeva. “Invariant Criteria for the Design of Multiple Beam Profile Emittance and Twiss Parameters Measurement Sections”, These Proceedings. |
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| TUPWO012 | Relations Between Projected Emittances and Eigenemittances | emittance, electron, quadrupole, coupling | 1904 |
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| We give necessary and sufficient conditions which two sets of positive real numbers must satisfy in order to be realizable as eigenemittances and projected emittances of a beam matrix. The information provided by these conditions sets limits on what one can to achieve when designing a beam line to perform advanced emittance manipulations (for example, round-to-flat beam transformations). | |||
| TUPWO020 | Error Analysis for C-ADS MEBT2 | emittance, cavity, linac, solenoid | 1925 |
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| A local achromatic scheme has been developed for C-ADS MEBT2. This paper presents the error analysis results for this MEBT2 scheme. The effects of magnet and cavity misalignment, static and dynamic errors of electric and magnetic field, the displacement of the input beam as well as the initial mismatches of the incoming beam will be studied. Beam trajectory correction scheme will also be discussed. | |||
| TUPWO037 | Design Study of the Low Energy Beam Transport System at RISP | rfq, solenoid, emittance, ion | 1955 |
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| We present the design status of LEBT for the RISP that consists of two 90 degree dipoles, a multi-harmonic buncher, pair solenoids, electrostatic quadrupoles and a high voltage platform. After ECR-IS with an energy of 10 keV/u, heavy-ion beams are selected by achromatic bending systems and then be bunched in the LEBT. A multi-harmonic buncher is used to achieve a small longitudinal emittance in the RFQ. We show the results on the optics design by using the TRANSPORT code and the beam tracking of two-charge beams by using the code IMPACT. We present the results and issues on beam dynamics simulaitons in the designed LEBT system. | |||
| WEPWO055 | Fabrication and Testing of SSR1 Resonators for PXIE | cavity, cryomodule, linac, vacuum | 2429 |
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| Fermilab is in the process of constructing a proton linac to accelerate a 1 mA CW beam up to 30 MeV. It will be a test for the front end of Project X and known as the Project X Injector Experiment (PXIE). The major goal of PXIE is the validation of the Project X concept and mitigation of technical risks. It is expected to be constructed in the period of 2012-2016. The PXIE linac consists of a Ion source and LEBT, a 162.5 MHz RFQ, a MEBT, a 162.5 MHz HWR cryomodule (designed and built at ANL) and a 325 MHZ SSR1 cryomodule (designed and built at FNAL). In this paper we present the recent advances in the development of the SSR1 resonators at Fermilab. Several bare SSR1 resonators have been processed, heat-treated and tested successfully in the Fermilab Vertical Test Stand. The outfitting of helium vessels is in process and the coarse-fine frequency tuning system has been designed and is currently being procured and tested. Details of the power coupler are also discussed. | |||
| WEPEA079 | A New Method to Integrate s-dependent Hamiltonian | insertion, insertion-device, undulator, focusing | 2693 |
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Funding: Work supported by U.S. DOE, Contract No. DE-AC02-98CH10886 The present theory to obtain higher order terms of beam dynamics is mostly through Taylor expansion and differentiation, for example, the Lie transformation. When 3-dimensional Hamiltonian is being considered the operation of integration becomes necessary. In this paper we will present a new integration theory, which leads to transfer maps for common accelerator elements based on 3-d Hamiltonians. Some physics insight was also gained from this theory, for example, the kick-map theory which is used for insertion device design and modeling, is a first-order approximation in our approach. |
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| THPME013 | MAGNET SUBSYSTEM OF HLS II | dipole, storage-ring, electron, quadrupole | 3537 |
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Funding: Work supported by Natural Science Foundation of China 11005106 To improve the performance of the Hefei Light Source (HLS), in particular to get higher brilliance synchrotron radiation and increase the number of straight section insertion devices, NSRL is now upgrading HLS to HLS II. Most of the magnets had to be replaced in this project. To measure the magnets, set of the magnetic measurement equipment in NSRL are also re-built. New magnets are sample measured, the discreteness and uniformity of integrated magnetic field all meet the requirements. Piecewise fitting and electron tracking of bending magnets for injector and beam transport line were performed and the results showed that the electron trajectory fitted the physical design well. |
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| THPME018 | Design of Dipole and Quadrupole for THz-FEL at CAEP | quadrupole, dipole, FEL, magnet-design | 3540 |
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| The high average power terahertz free electronic laser (THz-FEL) is being constructed at CAEP (China Academy of Engineering Physics), which is designed for lasing between 100-300 μm. The magnets of THz-FEL include 3 dipoles and 6 quadrupoles, and their fields and field quality were required by 6-9 MeV operation. This proceeding introduced the design and the main parameters of these magnets. The higher harmonic content of the magnetic field was also analyzed. All the design of magnets achieved the goal. | |||
| THPME047 | Progress of the RFQ Accelerator for PXIE | rfq, emittance, simulation, ion | 3618 |
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Funding: This work is supported by the Office of Science, United States Department of Energy under DOE contract DE-AC02-05CH11231. The proposed Project X Injector Experiment (PXIE) is currently under development at Fermilab. PXIE is an R&D test accelerator that will replicate the front-end portion of Project X. The PXIE accelerator complex consists of a H− ion source(s), low-energy beam transport (LEBT), 162.5 MHz normal conducting CW Radio-Frequency-Quadrupole (RFQ) accelerator, medium-energy beam transport (MEBT), broad-band beam chopper(s) and two superconducting cryomodules. In this paper, we will review and present recent progress of the PXIE RFQ, which will include an overview of the RFQ beam dynamics design, RF structure design, detailed thermal and mechanical analyses, fabrication test results and fabrication plan and schedule. |
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| THPWO021 | Gabor Lens Performance Studies at the GSI High Current Test Injector | emittance, ion, electron, space-charge | 3806 |
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| At the Institute for Applied Physics (IAP) the application of Gabor space charge lenses as a focusing device for low energy ion beams has already been studied for several years. Inside Gabor lenses electrons are confined by external fields. In case of a homogeneously distributed electron cloud the resulting linear electric space charge field enables the focusing of high intensity heavy ion beams without aberrations. Therefore, the Gabor lens is a promising approach for mass-independent focusing and possible space charge compensation of ion beams. In mid-2012 the performance of a prototype lens has successfully been tested at the GSI High Current Test Injector (HOSTI). GSI and IAP are currently investigating the possible application of such a device for the continuous operation at the High Current Injector (HSI) for FAIR. This contribution will present the results of beam transport experiments at HOSTI as well as the determination of related plasma properties. | |||
| THPWO035 | Numerical Study on the Effect of Magnetic Shield of a Bunch Shape Monitor in J-PARC Linac | electron, linac, simulation, quadrupole | 3842 |
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| In the annual shutdown period of 2012, three bunch shape monitors (BSMs) have been installed to the J-PARC linac beam transport line at the downstream of the 181-MeV separated DTL. To measure the longitudinal micro-bunch shape, the BSM detects the electrons produced by the accelerated protons hitting the negatively energized wire. Due to the space limitation, the each BSM is installed at the center of the quadrupole doublet, where the fringe field from the quadrupole magnets exists. It has been observed that the fringe field significantly affects the orbit of the emitted electrons. To shield the magnetic field, iron plates have been inserted to the spaces between the quadrupole magnets and BSM. This causes changes of the total magnetic flux density (GL) and the amount of quadrupole component of the fringe field. In this paper, numerical estimation of the shield effect is presented. | |||
| THPWO037 | Status and Progress of the J-PARC 3 GeV RCS | injection, target, neutron, extraction | 3848 |
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| The J-PARC rapid cycling synchrotron (RCS) has been delivered 300kW beam to both the MLF and the MR with high reliability and small beam loss for user operation. To realize simultaneously two kinds of beam shape which are required from the MLF and the MR, two pulse dipole magnets for injection painting were installed in the beam transport line from the Linac to the RCS. It was successful to make two kinds of beam shape with injection painting bump magnets and these added pulse dipole magnets. This injection painting system is used for user operation and works well for reduction of beam losses. Not only user operation but also high power beam test was performed, and beam power of 524kW for 35 second was achieved with low beam loss in the RCS. Almost all beam loss was localized at the ring collimator and the loss rate was about 2% and this was acceptable because design value of the beam loss was 3%. This power corresponds to 1.8MW for 400MeV injection in terms of the Lasslett tune shift. In this high-intensity trial, significant progress toward design output beam power of 1 MW was demonstrated. The status and progress of the RCS in J-PARC are presented. | |||
| THPWO086 | Status of the RAL Front End Test Stand | rfq, ion, ion-source, status | 3963 |
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| The Front End Test Stand (FETS) under construction at RAL is a demonstrator for the front end systems of a future high power proton linac. Possible applications include a linac upgrade for the ISIS spallation neutron source, new future neutron sources, accelerator driven sub-critical systems, a neutrino factory etc. Designed to deliver a 60mA H-minus beam at 3MeV with a 10% duty factor, FETS consists of a high brightness ion source, magnetic low energy beam transport (LEBT), 4-vane 324MHz radio frequency quadrupole, medium energy beam transport (MEBT) containing a high speed beam chopper and non-destructive photo-detachment diagnostics. This paper describes the current status of the project and future plans. | |||