IPAC2012 - List of Keywords (beam-transport)

Paper	Title	Other Keywords	Page
MOEPPB005	Initial Commissioning of NDCX-II	induction, diagnostics, solenoid, ion	85
	S.M. Lidia, D. Arbelaez, W.G. Greenway, J.-Y. Jung, J.W. Kwan, T.M. Lipton, A. Pekedis, P.K. Roy, P.A. Seidl, J.H. Takakuwa, W.L. Waldron LBNL, Berkeley, California, USA A. Friedman, D.P. Grote, W. M. Sharp LLNL, Livermore, California, USA E.P. Gilson PPPL, Princeton, New Jersey, USA
	Funding: This work was performed under the auspices of the U.S Department of Energy by LLNL under contract DE AC52 07NA27344, and by LBNL under contract. DE-AC02-05CH11231. The Neutralized Drift Compression Experiment-II (NDCX-II) will generate ion beam pulses for studies of Warm Dense Matter and heavy-ion-driven Inertial Fusion Energy. The machine will accelerate 20-50 nC of Li+ to 1.2-3 MeV energy, starting from a 10.9-cm alumino-silicate ion source. At the end of the accelerator the ions are focused to a sub-mm spot size onto a thin foil (planar) target. The pulse duration is compressed from ~500 ns at the source to sub-ns at the target following beam transport in a neutralizing plasma. We first describe the injector, accelerator, transport, final focus and diagnostic facilities. We then report on the results of early commissioning studies that characterize beam quality and beam transport, acceleration waveform shaping and beam current evolution. We present WARP simulation results to benchmark against the experimental measurements.

MOPPC056	The SolMaxP Code	plasma, simulation, laser, target	259
	A. Chancé, N. Chauvin, R.D. Duperrier CEA/DSM/IRFU, France
	In modern sciences, use of high performance computing (HPC) has become a necessity to move forward in the modeling of complex systems. For large-scale instruments like accelerators, HPC permits the virtual prototyping of very onerous parts and, thus, helps to reduce development costs. The SolMaxP code (for Solving Maxwell in Plasma) has been developed to allow complex simulations of multi-species plasma coupled with electromagnetic fields, whether the electromagnetic background is or is not self-consistent with the plasma dynamics. This paper presents the main algorithm of the code and gives several examples of applications.

MOPPD049	The Layout of the High Energy Beam Transport for the European Spallation Source	target, octupole, linac, quadrupole	475
	A.I.S. Holm, S.P. Møller, H.D. Thomsen ISA, Aarhus, Denmark
	The status of the High Energy Beam Transport (HEBT) line for the European Spallation Source (ESS) is presented. The HEBT brings the beam from the underground linac to the target at surface level. The main design objectives of the HEBT, such as space for upgrades, producing the desired target footprint etc. are discussed and the preferred design is shown. Large amplitude particles, a halo, are formed in the last part of the linac. Hence, every given value of the peak current density at the target is correlated with a certain power deposited outside the beam footprint. This correlation is studied and optimized. Furthermore, first studies of the vertical stability of the beam footprint and profile on target due to misalignment or mismatch of the incoming beam are made.

MOPPD053	Reduction of Outgassing from the Ferrite Cores in the Kicker Magnet of J-PARC RCS	vacuum, kicker, high-voltage, proton	487
	N. Ogiwara, Y. Hikichi, J. Kamiya, M. Kinsho, M. Nishikawa, K. Suganuma, T. Yanagibashi JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	Kicker magnets are used to kick out the accelerated beam to the beam transport lines in the RCS of the J-PARC. A high voltage is applied to kickers for a short period, so they must be installed in a vacuum to prevent discharge. Therefore, it is important to reduce the outgassing of water vapor from the ferrite cores. After bake-out at 200°C for 300 hours, the outgassing rate decreased to less than 1×10^-7 Pam/s. However, the small amount of water vapor and carbon monoxide were emitted from the ferrite cores at charging voltage of 80 kV. This time, we have decided to construct the reserve magnets with very low outgassing at high-voltage discharge. First of all, the thermal desorption behavior of the ferrite was investigated. Water vapor has two peaks: at ~ 100°C and 350°C. Carbon monoxide is rather largely emitted until 300°C. From these results, the ferrite cores were vacuum-fired at 450°C for 10 h. Then the good properties for the magnetic cores were confirmed. And now the assembling of the kicker magnet is undertaken. The performance of the kicker magnet made of the vacuum-fired ferrite will be shown in this meeting.

MOPPD054	Effect of the 2011 Great East Japan Earthquake in the Injection and Extraction of the J-PARC 3-GeV RCS	injection, extraction, septum, simulation	490
	P.K. Saha, H. Harada, H. Hotchi, S.I. Meigo, N. Tani, M. Yoshimoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	In the 3-GeV rapid cycling synchrotron (RCS) of the Japan Proton Accelerator Research Complex (J-PARC), the injection and extraction systems play important roles for the beam injection and extraction, respectively. Unfortunately, the 2011 great east Japan earthquake had a serious impact on the ongoing schedule due to the big damage of the whole accelerator facility and the infrastructure as well. The injection and extraction including the beam transport lines magnets suffered a noticeable displacement resulting with alignment errors. As realignment of the RCS magnets can not be done in this year, then based on the post earthquake measured alignment data, we have estimated the effect as well as possible solutions on the injected and extracted beam for as usual operation. Fortunately, the simulation results shows that there would not be any serious impact on both injected as well as extracted beam with present alignment errors and thus user operation can be resume as expected. The simulation result together with some experimental results will be presented.

MOPPP038	Optics Design and Layout for the Electron Beam Test Facility at Daresbury Laboratory	gun, quadrupole, laser, emittance	646
	D. Angal-Kalinin, J.W. McKenzie, B.L. Militsyn STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom J.K. Jones Cockcroft Institute, Warrington, Cheshire, United Kingdom
	An Electron Beam Test Facility (EBTF) is being developed at Daresbury Laboratory to provide the beam for industrial applications and as a front end of future light source facility test under consideration. The RF photoinjector will deliver ~6 MeV beam to industrial users* and will serve as an injector for the future light source facility under consideration at Daresbury*. The Photoinjector design in first phase consists of 2.5 cell RF gun (on loan from Strathclyde) to be driven by Ti:S laser. The photo injector design is aimed to deliver bunches with 10-250 pC bunch charge at low transverse emittances and short bunch lengths. The beam transport optics design described in this paper includes a dedicated diagnostics section capable of measuring ultra short and ultra low emittance bunches and transport to two user areas. P. McIntosh, these proceedings. ** J. Clarke, these proceedings.

TUPPC008	Twiss Parameters of Coupled Particle Beams with Equal Eigenemittances	emittance	1167
	V. Balandin, R. Brinkmann, W. Decking, N. Golubeva DESY, Hamburg, Germany
	The parametrization of coupled beam motion has been studied intensively over the past decades. Nevertheless, there is still no representation of general coupled motion that would be as elegant and as complete as the one dimensional Courant-Snyder theory. In this context the consideration of different partial cases plays an important highlighting role, and in this paper we study the parametrization of coupled particle beams with equal eigenemittances. We show that such beams allow description which in many aspects resembles the one dimensional Courant-Snyder theory.

TUPPC069	Third-Order Apochromatic Drift-Quadrupole Beamline	quadrupole, betatron, resonance, focusing	1329
	N. Golubeva, V. Balandin, R. Brinkmann, W. Decking DESY, Hamburg, Germany
	We have shown that for every drift-quadrupole system there exists an unique set of Twiss parameters (apochromatic Twiss parameters), which will be transported through that system without first order chromatic distortions. In this paper we continue the development of the theory of apochromatic focusing and present the design of a straight drift-quadrupole system which can transport apochromatic beam ellipses without influence not only of the second but also of the third order chromatic and geometric aberrations of the beamline transfer map. V.Balandin, R.Brinkmann, W.Decking, N.Golubeva. Apochromatic Beam Transport in Drift-Quadrupole Systems. Proceedings of IPAC'10, Kyoto, Japan.

WEPPR017	Wake Fields Effects for the eRHIC Project	cavity, wakefield, vacuum, electron	2976
	A.V. Fedotov, S.A. Belomestnykh, D. Kayran, V. Litvinenko, V. Ptitsyn BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. An Energy Recovery Linac (ERL) with a high peak electron bunch current is proposed for the Electron-Ion collider (eRHIC) project at the Brookhaven National Laboratory. The present design is based on the multi-pass electron beam transport in existing tunnel of the Relativistic Heavy Ion Collider (RHIC). As a result of a high peak current and a very long beam transport, consideration of various collective beam dynamics effects becomes important. Here we summarize effects of the coherent synchrotron radiation, resistive wall, accelerating cavities and wall roughness on the resulting energy spread and energy loss for several scenarios of the eRHIC project, including results for different electron distributions. A possible correction scheme of accumulated correlated energy spread is also presented.

THPPC007	Coupling Cavity Design of RF Input Coupler Tests for the IFMIF/EVEDA Prototype RFQ Linac	coupling, cavity, rfq, linac	3284
	S. Maebara JAEA, Ibaraki-ken, Japan M. Ichikawa Japan Atomic Energy Agency (JAEA), International Fusion Energy Research Center (IFERC), Rokkasho, Kamikita, Aomori, Japan
	In the design of prototype RFQ linac for the IFMIF/EVEDA Project, a 175MHz RFQ, which has a longitudinal length of 9.78m, was proposed to accelerate deuteron beam up to 5MeV. The operation frequency of 175MHz was selected to accelerate a large current of 125mA in cw mode. The overall driving RF power of 1.28 MW by 8 RF input couplers has to be injected to the RFQ cavity. For the transmitted RF power tests of RF couplers, a coupling cavity to connect with two RF couplers is needed. For this purpose, two types of coupling cavities for the 175MHz have been designed. One is a capacitive coupling cavity with a co-axial waveguide and double loop coupling structures, and the other one is a ridge cavity type with a rectangular waveguide. In this article, these RF designs and engineering designs will be presented in detail.

THPPC050	Effects of Grids in Drift Tubes	impedance, proton, linac, DTL	3401
	M. Okamura BNL, Upton, Long Island, New York, USA H. Yamauchi Time Corporation, Hiroshima, Japan
	In 2011, we upgraded a 200 MHz buncher in the proton injector for the AGS – RHIC complex. In the buncher we installed four grids made of tungsten to improve a transit time factor of the buncher. The grid installed drift tubes have 32 mm of inner diameter and the each grid consists of four quadrants. The quadrants were cut out precisely from 1mm thick tungsten plates by a CNC wire cutting EDM. In the conference the 3D electric field design and performance of the grid will be discussed. Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.

THPPP051	Status of the RAL Front End Test Stand	ion, ion-source, rfq, simulation	3856
	A.P. Letchford, M.A. Clarke-Gayther, D.C. Faircloth, S.R. Lawrie STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom S.M.H. Alsari, M. Aslaninejad, A. Kurup, P. Savage Imperial College of Science and Technology, Department of Physics, London, United Kingdom J.J. Back University of Warwick, Coventry, United Kingdom G.E. Boorman, A. Bosco Royal Holloway, University of London, Surrey, United Kingdom C. Gabor, D.C. Plostinar STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom A. Garbayo AVS, Eibar, Gipuzkoa, Spain S. Jolly UCL, London, United Kingdom J.K. Pozimski STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
	The Front End Test Stand (FETS) under construction at RAL is a demonstrator for 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 plus comprehensive diagnostics. This paper describes the current status of the project and future plans.

THPPP063	CW Room Temperature Re-buncher for the Project X Front End	cavity, linac, simulation, vacuum	3880
	G.V. Romanov, M.H. Awida, M. Chen, I.V. Gonin, S. Kazakov, R.A. Kostin, V.A. Lebedev, N. Solyak, V.P. Yakovlev Fermilab, Batavia, USA
	At Fermilab there is a plan to construct the Project X Injector Experiment (PXIE) facility - a prototype of the front end of the Project X, a multi-MW proton source based on a superconducting linac. The construction and successful operations of this facility will validate the concept for the Project X front end, thereby minimizing the primary technical risk element within the Project. The front end of the linac contains a cw room-temperature MEBT section which comprises an ion source, RFQ, and high-bandwidth bunch selective chopper. The length of the MEBT exceeds 9 m, so three re-bunching cavities are used to support the beam longitudinal dynamics. The paper reports RF design of the re-bunchers along with preliminary beam dynamic and thermal analysis of the cavities.

THPPP065	The FNAL Injector Upgrade Status	rfq, emittance, extraction, vacuum	3886
	C.-Y. Tan, D.S. Bollinger, K.L. Duel, P.R. Karns, J.R. Lackey, W. Pellico, V.E. Scarpine, R.E. Tomlin Fermilab, Batavia, USA
	Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy. The new FNAL H⁻ injector upgrade is currently being tested before installation in the Spring 2012 shutdown of the accelerator complex. This line consists of an H⁻ source, low energy beam transport (LEBT) and 200 MHz RFQ. Beam measurements have been performed to validate the design before installation. The results of the beam measurements are presented in this paper.

THPPP074	Chopping High Intensity Proton Beams Using a Pulsed Wien Filter	focusing, proton, dipole, emittance	3907
	C. Wiesner, L.P. Chau, H. Dinter, M. Droba, O. Meusel, I. Müller, D. Noll, U. Ratzinger IAP, Frankfurt am Main, Germany
	Chopping high intensity beams at low energies poses substantial challenges. A novel ExB chopper system for proton beams of up to 200 mA at energies of 120 keV is being developed for the accelerator driven neutron source FRANZ. It uses a Wien filter-type ExB configuration consisting of a static magnetic deflection field and a pulsed electric compensation field to deliver 100 ns beam pulses. The setup minimizes the risk of voltage breakdowns and provides secure beam dumping outside the transport line. In order to prevent beam aberrations and emittance growth careful matching of electric and magnetic deflection forces is required. Detailed numerical studies for the field design and their effects on beam transport were conducted. An H-type dipole magnet with special transverse and longitudinal pole contours was manufactured and combined with shielding tubes to shape the magnetic field. The electric field is driven by a HV pulse generator providing ±6 kV at a repetition rate of 250 kHz. Accurate layout of the deflector plates is required in order to tackle the issues of field quality, cooling and spark prevention. Transport simulations and beam deflection experiments are presented. U. Ratzinger et al., "The Driver Linac of the Neutron Source FRANZ," Proc. of IPAC2011, WEPS040, P. 2577 (2011).

THPPP083	Status of J-PARC 3 GeV RCS	injection, extraction, beam-losses, vacuum	3927
	M. Kinsho JAEA/J-PARC, Tokai-mura, Japan
	J-PARC RCS have delivered beam progressively since 2008. The RCS ramped up the beam power, and delivered beam of 300kW equivalent and 220kW to MR and MLF, respectively, before the earthquake disaster. The RCS was heavily affected by the last Great East Japan Earthquake. At the RCS, the circulating road went wavy and the yard area for electricity and cooling water devices was heavily distorted. We have investigated damages of each device and also have tried to restore beam operation. From middle of December last year we could start beam test and also would start to deliver beam to MR and MLF for user operation from this January. We have been performed not only recovery works but also improvement of the RCS for realizing high power stable operation with low beam losses. I report status of beam operation and near future plan for the RCS.

Paper

Title

Other Keywords

Page

MOEPPB005

Initial Commissioning of NDCX-II

induction, diagnostics, solenoid, ion

85

S.M. Lidia, D. Arbelaez, W.G. Greenway, J.-Y. Jung, J.W. Kwan, T.M. Lipton, A. Pekedis, P.K. Roy, P.A. Seidl, J.H. Takakuwa, W.L. Waldron
LBNL, Berkeley, California, USA
A. Friedman, D.P. Grote, W. M. Sharp
LLNL, Livermore, California, USA
E.P. Gilson
PPPL, Princeton, New Jersey, USA

Funding: This work was performed under the auspices of the U.S Department of Energy by LLNL under contract DE AC52 07NA27344, and by LBNL under contract. DE-AC02-05CH11231.
The Neutralized Drift Compression Experiment-II (NDCX-II) will generate ion beam pulses for studies of Warm Dense Matter and heavy-ion-driven Inertial Fusion Energy. The machine will accelerate 20-50 nC of Li+ to 1.2-3 MeV energy, starting from a 10.9-cm alumino-silicate ion source. At the end of the accelerator the ions are focused to a sub-mm spot size onto a thin foil (planar) target. The pulse duration is compressed from ~500 ns at the source to sub-ns at the target following beam transport in a neutralizing plasma. We first describe the injector, accelerator, transport, final focus and diagnostic facilities. We then report on the results of early commissioning studies that characterize beam quality and beam transport, acceleration waveform shaping and beam current evolution. We present WARP simulation results to benchmark against the experimental measurements.

MOPPC056

The SolMaxP Code

plasma, simulation, laser, target

259

A. Chancé, N. Chauvin, R.D. Duperrier
CEA/DSM/IRFU, France

In modern sciences, use of high performance computing (HPC) has become a necessity to move forward in the modeling of complex systems. For large-scale instruments like accelerators, HPC permits the virtual prototyping of very onerous parts and, thus, helps to reduce development costs. The SolMaxP code (for Solving Maxwell in Plasma) has been developed to allow complex simulations of multi-species plasma coupled with electromagnetic fields, whether the electromagnetic background is or is not self-consistent with the plasma dynamics. This paper presents the main algorithm of the code and gives several examples of applications.

MOPPD049

The Layout of the High Energy Beam Transport for the European Spallation Source

target, octupole, linac, quadrupole

475

A.I.S. Holm, S.P. Møller, H.D. Thomsen
ISA, Aarhus, Denmark

The status of the High Energy Beam Transport (HEBT) line for the European Spallation Source (ESS) is presented. The HEBT brings the beam from the underground linac to the target at surface level. The main design objectives of the HEBT, such as space for upgrades, producing the desired target footprint etc. are discussed and the preferred design is shown. Large amplitude particles, a halo, are formed in the last part of the linac. Hence, every given value of the peak current density at the target is correlated with a certain power deposited outside the beam footprint. This correlation is studied and optimized. Furthermore, first studies of the vertical stability of the beam footprint and profile on target due to misalignment or mismatch of the incoming beam are made.

MOPPD053

Reduction of Outgassing from the Ferrite Cores in the Kicker Magnet of J-PARC RCS

vacuum, kicker, high-voltage, proton

487

N. Ogiwara, Y. Hikichi, J. Kamiya, M. Kinsho, M. Nishikawa, K. Suganuma, T. Yanagibashi
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

Kicker magnets are used to kick out the accelerated beam to the beam transport lines in the RCS of the J-PARC. A high voltage is applied to kickers for a short period, so they must be installed in a vacuum to prevent discharge. Therefore, it is important to reduce the outgassing of water vapor from the ferrite cores. After bake-out at 200°C for 300 hours, the outgassing rate decreased to less than 1×10^-7 Pam/s. However, the small amount of water vapor and carbon monoxide were emitted from the ferrite cores at charging voltage of 80 kV. This time, we have decided to construct the reserve magnets with very low outgassing at high-voltage discharge. First of all, the thermal desorption behavior of the ferrite was investigated. Water vapor has two peaks: at ~ 100°C and 350°C. Carbon monoxide is rather largely emitted until 300°C. From these results, the ferrite cores were vacuum-fired at 450°C for 10 h. Then the good properties for the magnetic cores were confirmed. And now the assembling of the kicker magnet is undertaken. The performance of the kicker magnet made of the vacuum-fired ferrite will be shown in this meeting.

MOPPD054

Effect of the 2011 Great East Japan Earthquake in the Injection and Extraction of the J-PARC 3-GeV RCS

injection, extraction, septum, simulation

490

P.K. Saha, H. Harada, H. Hotchi, S.I. Meigo, N. Tani, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

In the 3-GeV rapid cycling synchrotron (RCS) of the Japan Proton Accelerator Research Complex (J-PARC), the injection and extraction systems play important roles for the beam injection and extraction, respectively. Unfortunately, the 2011 great east Japan earthquake had a serious impact on the ongoing schedule due to the big damage of the whole accelerator facility and the infrastructure as well. The injection and extraction including the beam transport lines magnets suffered a noticeable displacement resulting with alignment errors. As realignment of the RCS magnets can not be done in this year, then based on the post earthquake measured alignment data, we have estimated the effect as well as possible solutions on the injected and extracted beam for as usual operation. Fortunately, the simulation results shows that there would not be any serious impact on both injected as well as extracted beam with present alignment errors and thus user operation can be resume as expected. The simulation result together with some experimental results will be presented.

MOPPP038

Optics Design and Layout for the Electron Beam Test Facility at Daresbury Laboratory

gun, quadrupole, laser, emittance

646

D. Angal-Kalinin, J.W. McKenzie, B.L. Militsyn
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
J.K. Jones
Cockcroft Institute, Warrington, Cheshire, United Kingdom

An Electron Beam Test Facility (EBTF) is being developed at Daresbury Laboratory to provide the beam for industrial applications and as a front end of future light source facility test under consideration. The RF photoinjector will deliver ~6 MeV beam to industrial users* and will serve as an injector for the future light source facility under consideration at Daresbury**. The Photoinjector design in first phase consists of 2.5 cell RF gun (on loan from Strathclyde) to be driven by Ti:S laser. The photo injector design is aimed to deliver bunches with 10-250 pC bunch charge at low transverse emittances and short bunch lengths. The beam transport optics design described in this paper includes a dedicated diagnostics section capable of measuring ultra short and ultra low emittance bunches and transport to two user areas.
* P. McIntosh, these proceedings.
** J. Clarke, these proceedings.

TUPPC008

Twiss Parameters of Coupled Particle Beams with Equal Eigenemittances

emittance

1167

V. Balandin, R. Brinkmann, W. Decking, N. Golubeva
DESY, Hamburg, Germany

The parametrization of coupled beam motion has been studied intensively over the past decades. Nevertheless, there is still no representation of general coupled motion that would be as elegant and as complete as the one dimensional Courant-Snyder theory. In this context the consideration of different partial cases plays an important highlighting role, and in this paper we study the parametrization of coupled particle beams with equal eigenemittances. We show that such beams allow description which in many aspects resembles the one dimensional Courant-Snyder theory.

TUPPC069

Third-Order Apochromatic Drift-Quadrupole Beamline

quadrupole, betatron, resonance, focusing

1329

N. Golubeva, V. Balandin, R. Brinkmann, W. Decking
DESY, Hamburg, Germany

We have shown that for every drift-quadrupole system there exists an unique set of Twiss parameters (apochromatic Twiss parameters), which will be transported through that system without first order chromatic distortions*. In this paper we continue the development of the theory of apochromatic focusing and present the design of a straight drift-quadrupole system which can transport apochromatic beam ellipses without influence not only of the second but also of the third order chromatic and geometric aberrations of the beamline transfer map.
* V.Balandin, R.Brinkmann, W.Decking, N.Golubeva. Apochromatic Beam Transport in Drift-Quadrupole Systems. Proceedings of IPAC'10, Kyoto, Japan.

WEPPR017

Wake Fields Effects for the eRHIC Project

cavity, wakefield, vacuum, electron

2976

A.V. Fedotov, S.A. Belomestnykh, D. Kayran, V. Litvinenko, V. Ptitsyn
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
An Energy Recovery Linac (ERL) with a high peak electron bunch current is proposed for the Electron-Ion collider (eRHIC) project at the Brookhaven National Laboratory. The present design is based on the multi-pass electron beam transport in existing tunnel of the Relativistic Heavy Ion Collider (RHIC). As a result of a high peak current and a very long beam transport, consideration of various collective beam dynamics effects becomes important. Here we summarize effects of the coherent synchrotron radiation, resistive wall, accelerating cavities and wall roughness on the resulting energy spread and energy loss for several scenarios of the eRHIC project, including results for different electron distributions. A possible correction scheme of accumulated correlated energy spread is also presented.

THPPC007

Coupling Cavity Design of RF Input Coupler Tests for the IFMIF/EVEDA Prototype RFQ Linac

coupling, cavity, rfq, linac

3284

S. Maebara
JAEA, Ibaraki-ken, Japan
M. Ichikawa
Japan Atomic Energy Agency (JAEA), International Fusion Energy Research Center (IFERC), Rokkasho, Kamikita, Aomori, Japan

In the design of prototype RFQ linac for the IFMIF/EVEDA Project, a 175MHz RFQ, which has a longitudinal length of 9.78m, was proposed to accelerate deuteron beam up to 5MeV. The operation frequency of 175MHz was selected to accelerate a large current of 125mA in cw mode. The overall driving RF power of 1.28 MW by 8 RF input couplers has to be injected to the RFQ cavity. For the transmitted RF power tests of RF couplers, a coupling cavity to connect with two RF couplers is needed. For this purpose, two types of coupling cavities for the 175MHz have been designed. One is a capacitive coupling cavity with a co-axial waveguide and double loop coupling structures, and the other one is a ridge cavity type with a rectangular waveguide. In this article, these RF designs and engineering designs will be presented in detail.

THPPC050

Effects of Grids in Drift Tubes

impedance, proton, linac, DTL

3401

M. Okamura
BNL, Upton, Long Island, New York, USA
H. Yamauchi
Time Corporation, Hiroshima, Japan

In 2011, we upgraded a 200 MHz buncher in the proton injector for the AGS – RHIC complex. In the buncher we installed four grids made of tungsten to improve a transit time factor of the buncher. The grid installed drift tubes have 32 mm of inner diameter and the each grid consists of four quadrants. The quadrants were cut out precisely from 1mm thick tungsten plates by a CNC wire cutting EDM. In the conference the 3D electric field design and performance of the grid will be discussed.
Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.

THPPP051

Status of the RAL Front End Test Stand

ion, ion-source, rfq, simulation

3856

A.P. Letchford, M.A. Clarke-Gayther, D.C. Faircloth, S.R. Lawrie
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
S.M.H. Alsari, M. Aslaninejad, A. Kurup, P. Savage
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
J.J. Back
University of Warwick, Coventry, United Kingdom
G.E. Boorman, A. Bosco
Royal Holloway, University of London, Surrey, United Kingdom
C. Gabor, D.C. Plostinar
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
A. Garbayo
AVS, Eibar, Gipuzkoa, Spain
S. Jolly
UCL, London, United Kingdom
J.K. Pozimski
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom

The Front End Test Stand (FETS) under construction at RAL is a demonstrator for 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 plus comprehensive diagnostics. This paper describes the current status of the project and future plans.

THPPP063

CW Room Temperature Re-buncher for the Project X Front End

cavity, linac, simulation, vacuum

3880

G.V. Romanov, M.H. Awida, M. Chen, I.V. Gonin, S. Kazakov, R.A. Kostin, V.A. Lebedev, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, USA

At Fermilab there is a plan to construct the Project X Injector Experiment (PXIE) facility - a prototype of the front end of the Project X, a multi-MW proton source based on a superconducting linac. The construction and successful operations of this facility will validate the concept for the Project X front end, thereby minimizing the primary technical risk element within the Project. The front end of the linac contains a cw room-temperature MEBT section which comprises an ion source, RFQ, and high-bandwidth bunch selective chopper. The length of the MEBT exceeds 9 m, so three re-bunching cavities are used to support the beam longitudinal dynamics. The paper reports RF design of the re-bunchers along with preliminary beam dynamic and thermal analysis of the cavities.

THPPP065

The FNAL Injector Upgrade Status

rfq, emittance, extraction, vacuum

3886

C.-Y. Tan, D.S. Bollinger, K.L. Duel, P.R. Karns, J.R. Lackey, W. Pellico, V.E. Scarpine, R.E. Tomlin
Fermilab, Batavia, USA

Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
The new FNAL H⁻ injector upgrade is currently being tested before installation in the Spring 2012 shutdown of the accelerator complex. This line consists of an H⁻ source, low energy beam transport (LEBT) and 200 MHz RFQ. Beam measurements have been performed to validate the design before installation. The results of the beam measurements are presented in this paper.

THPPP074

Chopping High Intensity Proton Beams Using a Pulsed Wien Filter

focusing, proton, dipole, emittance

3907

C. Wiesner, L.P. Chau, H. Dinter, M. Droba, O. Meusel, I. Müller, D. Noll, U. Ratzinger
IAP, Frankfurt am Main, Germany

Chopping high intensity beams at low energies poses substantial challenges. A novel ExB chopper system for proton beams of up to 200 mA at energies of 120 keV is being developed for the accelerator driven neutron source FRANZ*. It uses a Wien filter-type ExB configuration consisting of a static magnetic deflection field and a pulsed electric compensation field to deliver 100 ns beam pulses. The setup minimizes the risk of voltage breakdowns and provides secure beam dumping outside the transport line. In order to prevent beam aberrations and emittance growth careful matching of electric and magnetic deflection forces is required. Detailed numerical studies for the field design and their effects on beam transport were conducted. An H-type dipole magnet with special transverse and longitudinal pole contours was manufactured and combined with shielding tubes to shape the magnetic field. The electric field is driven by a HV pulse generator providing ±6 kV at a repetition rate of 250 kHz. Accurate layout of the deflector plates is required in order to tackle the issues of field quality, cooling and spark prevention. Transport simulations and beam deflection experiments are presented.
* U. Ratzinger et al., "The Driver Linac of the Neutron Source FRANZ," Proc. of IPAC2011, WEPS040, P. 2577 (2011).

THPPP083

Status of J-PARC 3 GeV RCS

injection, extraction, beam-losses, vacuum

3927

M. Kinsho
JAEA/J-PARC, Tokai-mura, Japan

J-PARC RCS have delivered beam progressively since 2008. The RCS ramped up the beam power, and delivered beam of 300kW equivalent and 220kW to MR and MLF, respectively, before the earthquake disaster. The RCS was heavily affected by the last Great East Japan Earthquake. At the RCS, the circulating road went wavy and the yard area for electricity and cooling water devices was heavily distorted. We have investigated damages of each device and also have tried to restore beam operation. From middle of December last year we could start beam test and also would start to deliver beam to MR and MLF for user operation from this January. We have been performed not only recovery works but also improvement of the RCS for realizing high power stable operation with low beam losses. I report status of beam operation and near future plan for the RCS.