Keyword: ion-source
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MOP142 Development of Picosecond CO2 Laser Driver for an MeV Ion Source laser, ion, proton, plasma 355
 
  • S. Tochitsky, D.J. Haberberger, C. Joshi
    UCLA, Los Angeles, California, USA
 
  Funding: This work is supported by DOE grant DE-FG02-92ER40727.
Laser-Driven Ion Acceleration in thin foils has demonstrated high-charge, low-emittance MeV ion beams with a picosecond duration. Such high-brightness beams are very attractive for a compact ion source or an injector for RF accelerators. However in the case of foils scaling of the pulse repetition rate and improving shot-to-shot reproducibility is a serious challenge. CO2 laser-plasma interactions provide a possibility for using a debris free gas jet for target normal sheath acceleration of ions. Gas jets have the advantage of precise density control around the critical plasma density for 10 um pulses (1019 cm-3) and can be run at 1-10 Hz. The master oscillator–power amplifier CO2 laser system at the UCLA Neptune Laboratory is being upgraded to generate 1 J, 3 ps pulses at 1Hz. For this purpose, a new 8 atm CO2 module is used to amplify a 3 ps pulse to ~10 GW level. Final amplification is realized in a 1-m long TEA CO2 amplifier, for which the bandwidth necessary for 3 ps pulses is provided by the field broadening mechanism. Modeling of the pulse amplification shows that ~0.3 TW power is achievable that should be sufficient for producing 1-3 MeV H+ protons from the gas plasma.
 
 
WEOBS6 Status and Specifications of a Project X Front-End Accelerator Test Facility at Fermilab cavity, rfq, linac, proton 1430
 
  • J. Steimel, R.L. Madrak, R.J. Pasquinelli, E. Peoples-Evans, R.C. Webber, D. Wildman
    Fermilab, Batavia, USA
 
  Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
This paper describes the construction and operational status of an accelerator test facility for Project X. The purpose of this facility is for Project X component development activities that benefit from beam tests and any development activities that require 325 MHz or 650 MHz RF power. It presently includes an H- beam line, a 325 MHz superconducting cavity test facility, a 325 MHz (pulsed) RF power source, and a 650 MHz (CW) RF power source. The paper also discusses some specific Project X components that will be tested in the facility.
 
slides icon Slides WEOBS6 [2.401 MB]  
 
WEP011 Low Energy Beam Transport Developments for the Bilbao Accelerator ion, rfq, simulation, dipole 1522
 
  • I. Bustinduy, D. de Cos
    ESS Bilbao, Bilbao, Spain
  • F.J. Bermejo
    Bilbao, Faculty of Science and Technology, Bilbao, Spain
  • V. Etxebarria, J. Portilla
    University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain
  • J. Feuchtwanger, Z. Izaola, J.L. Munoz, I. Rodríguez
    ESS-Bilbao, Zamudio, Spain
 
  Funding: European Spallation Source - Bilbao
In this work we present a future upgrade of the ESS-Bilbao multi-source Low Energy Transport System (LEBT). It consists of a set of solenoids and steering dipoles used to match the characteristics of both ion source beams i.e., the Electron Cyclotron Resonance (ECR) H+/D+ source and the H− Penning source, to the input specifications of the RFQ. Different configurations of the geometry and magnetic fields are studied in order to minimize the emittance growth along the LEBT, while providing the beam specifications required by the RFQ.
 
 
WEP076 Masking the Paul Trap Simulator Experiment (PTSX) Ion Source to Modify the Transverse Distribution Function and Study Beam Stability and Collective Oscillations ion, plasma, lattice, vacuum 1618
 
  • E.P. Gilson, R.C. Davidson, P. Efthimion, R. M. Majeski, E. Startsev, H. Wang
    PPPL, Princeton, New Jersey, USA
  • M. Dorf
    LLNL, Livermore, California, USA
 
  Funding: Research supported by the U.S. Department of Energy.
A variety of masks were installed on the Paul Trap Simulator Experiment (PTSX) cesium ion source in order to perform experiments with modified transverse distribution functions. Masks were used to block injection of ions into the PTSX chamber, thereby creating injected transverse beam distributions that were either hollow, apertured and centered, apertured and off-center, or comprising five beamlets. Experiments were performed using either trapped plasmas or the single-pass, streaming, mode of PTSX. The transverse streaming current profiles clearly demonstrated centroid oscillations. Further analysis of these profiles also shows the presence of certain collective beam modes, such as azimuthally symmetric radial modes. When these plasmas are trapped for thousands of lattice periods, the plasma quickly relaxes to a state with an elevated effective transverse temperature and is subsequently stable. Both sinusoidal and periodic step function waveforms were used and the resulting difference in the measured transverse profiles will be discussed.
 
 
WEP213 New Development of a RFQ Beam Matching Section rfq, emittance, ion, linac 1891
 
  • M. Baschke, N. Müller, A. Schempp, J.S. Schmidt
    IAP, Frankfurt am Main, Germany
 
  Funding: BMBF
Funneling is a method to increase low energy beam currents in multiple stages. The Frankfurt Funneling Experiment is a model of such a stage. The experiment is built up of two ion sources with electrostatic lens systems, a Two-Beam-RFQ accelerator, a funneling deflector and a beam diagnostic system. The two beams are bunched and accelerated in a Two-Beam RFQ. A funneling deflector combines the bunches to a common beam axis. Current work is the construction and beam tests of a new beam transport system between RFQ accelerator and deflector. With extended RFQ-electrodes the drift between the Two-Beam-RFQ and the rf-deflector will be minimized and therefore unwanted emittance growth reduced. First rf-measurements with the improved Two-Beam-RFQ will be presented.
 
 
WEP257 Spectroscopic Estimation of Plasma Parameters for ECR Ion Source in the Intense 14-MeV Neutron Generator being developed at IPR plasma, electron, ion, ECR 1963
 
  • S. Banerjee, M. Abhangi, T.K. Basu, J. Ghosh, S.C. Jakhar, N. Ramaiya, C.V.S. Rao, S.J. Vala
    Institute for Plasma Research, Bhat, Gandhinagar, India
  • P. Mehta
    Pandit Deendayal Petroleum University, Gandhinagar, India
 
  An accelerator based 14-MeV neutron generator, for fusion neutronics studies is being developed at IPR. ECR ion source is used to generate deuterium plasma. Electron density and temperature in the ECR plasma are measured using non-intrusive spectroscopic methods. Langmuir probes, though conventionally used for estimating local parameters in low-pressure microwave plasmas, are difficult to implement here owing to space constraint and heating of the probe from interaction with standing microwaves. Pure helium (He), He seeded hydrogen and deuterium plasmas are studied. Spectra for entire visible range are recorded for different fill pressures for a constant microwave power and different powers for a constant fill pressure. For optically thin plasmas of low density, line intensity ratio method can be used with appreciable reliability. CR model is used from ADAS (atomic data and analysis structure) to predict plasma parameters from suitable line ratios.
sbanerje@ipr.res.in
sudhir@ipr.res.in
Institute for Plasma Research
 
 
WEP264 Laser Ion Source With Long Pulse Width for RHIC-EBIS ion, solenoid, laser, plasma 1972
 
  • K. Kondo, M. Okamura
    BNL, Upton, Long Island, New York, USA
  • T. Kanesue
    Kyushu University, Department of Applied Quantum Physics and Nuclear Engineering, Fukuoka, Japan
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy and by the National Aeronautics and Space Administration.
The Electron Beam Ion Source (EBIS) at Brookhaven National Laboratory is a new heavy ion-projector for RHIC and NASA Space Radiation Laboratory. Laser Ion Source (LIS) with solenoid can supply many kinds of ion from solid targets and is suitable for long pulse length with low current as ion provider for RHIC-EBIS. In order to understand a plasma behavior for fringe field of solenoid, we measure current, pulse width and total ion charges by a new ion probe. The experimental result indicates that the solenoid confines the laser ablation plasma transversely.
 
 
WEP270 A High Current Density Li+ Alumino-silicate Ion Source for Target Heating Experiments ion, extraction, space-charge, target 1981
 
  • P.K. Roy, W.G. Greenway, J.W. Kwan, P.A. Seidl, W.L. Waldron
    LBNL, Berkeley, California, 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 NDCX-II accelerator has been designed for target heating experiments in the warm dense matter regime. It will use a large diameter (≈ 10.9 cm) Li+ doped alumino-silicate source with a pulse duration of 0.5 μs, and beam current of ≈ 93 mA. Characterization of a prototype lithium alumino-silicate sources is presented. Using 6.35 mm diameter prototype emitters (coated and sintered on a ≈ 75% porous tungsten substrate), at a temperature of ≈1275° C, a space-charge limited Li+ beam current density of ≈ 1 mA/cm2 was measured. At higher extraction voltage, the source is emission limited at around ≈ 1.5 mA/cm2, weakly dependent on the applied voltage. The lifetime of the ion source is ≈ 50 hours while pulsing the extraction voltage at 2 to 3 times per minute. Measurements under these conditions show that the lifetime of the ion source does not depend only on beam current extraction, and lithium loss may be dominated by neutral loss or by evaporation. The thickness of the coating does not affect the emission density. It is inferred that pulsed heating, synchronized with the beam pulse rate may increase the life time of a source.
 
 
WEP271 Development of a Permanent-Magnet Microwave Ion Source for a Sealed-Tube Neutron Generator ion, neutron, plasma, ECR 1984
 
  • O. Waldmann, B.A. Ludewigt
    LBNL, Berkeley, California, USA
 
  Funding: Supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
A microwave ion source has been designed and constructed for use with a sealed-tube, high-yield neutron generator. When operated with a tritium-deuterium gas mixture the generator will be capable of producing 5 · 1011 n/s in non-proliferation applications. Microwave ion sources are well suited for such a device because they can produce high extracted beam currents with a high atomic fraction at low gas pressures of 0.2 − 0.3 Pa required for sealed tube operation. The magnetic field strength for achieving electron cyclotron resonance (ECR) condition, 87.5 mT at 2.45 GHz microwave frequency, was generated and shaped with permanent magnets surrounding the plasma chamber and a ferromagnetic plasma electrode. This approach resulted in a compact ion source that matches the neutron generator requirements. The needed proton-equivalent extracted beam current density of 40 mA/cm2 was obtained at moderate microwave power levels of ∼ 400W. Results on magnetic field design, pressure dependency and atomic fraction measured for different wall materials are presented.
 
 
WEP273 Saddle RF Antenna H Ion Source Progress plasma, ion, extraction, gun 1987
 
  • V.G. Dudnikov, R.P. Johnson
    Muons, Inc, Batavia, USA
  • S. Murray, T.R. Pennisi, M. Santana, M.P. Stockli, R.F. Welton
    ORNL, Oak Ridge, Tennessee, USA
 
  Funding: Supported in part by USDOE Contract DE-AC05-00OR22725 and STTR Grant DE-SC0002690
In this project we are developing an RF H surface plasma source (SPS) with saddle (SA) RF antenna which will provide better power efficiency for high pulsed and average current, higher brightness with longer lifetime and higher reliability. Several versions of new plasma generators with a small AlN test chamber and different antennasandmagneticfieldconfigurationsweretestedin the SNS ion source Test Stand. A prototype SA SPS was installed in the Test Stand with a larger, normal-sized SNS AlN chamber that achieved unanalyzed peak currents of up to 67 mA with an apparent efficiency of 1.6 mA/kW. Control experiments with H beam produced by SNS SPS with internal and external antennas were conducted. A new version of the RF triggering plasma source (TPS) has been designed. A Saddle antenna SPS with water cooling is being fabricated for high duty factor testing.
 
 
WEP274 Broadband Antenna Matching Network Design and Application for RF Plasma Ion Source impedance, ion, plasma, simulation 1990
 
  • K.R. Shin
    ORNL RAD, Oak Ridge, Tennessee, USA
  • A.E. Fathy
    University of Tennessee, Knoxville, Tennessee, USA
  • Y.W. Kang, M.F. Piller
    ORNL, Oak Ridge, Tennessee, USA
 
  Funding: This work was supported by SNS through UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. DOE.
The RF ion source at Spallation Neutron Source has been upgraded to meet higher beam power requirement. One important subsystem for efficient operation of the ion source is the 2MHz RF impedance matching network. The real part of the antenna impedance is very small and is affected by plasma density for 2MHz operating frequency. Previous impedance matching network for the antenna has limited tuning capability to cover this potential variation of the antenna impedance since it employed a single tuning element and an impedance transformer. A new matching network with two tunable capacitors has been built and tested. This network can allow precision matching and increase the tunable range without using a transformer. A 5-element broadband matching network also has been designed, built and tested. The 5-element network allows wide band matching up to 50 kHz bandwidth from the resonance center of 2 MHz. The design procedure, simulation and test results are presented.
 
 
WEP275 Highly-Persistent SNS H Source Fueling 1-MW Beams with 7-9 kC Service Cycles plasma, ion, rfq, linac 1993
 
  • M.P. Stockli, T.W. Hardek, Y.W. Kang, S.N. Murray, T.R. Pennisi, M.F. Piller, M. Santana, R.F. Welton
    ORNL, Oak Ridge, Tennessee, USA
  • B. Han
    ORNL RAD, Oak Ridge, Tennessee, USA
 
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy.
Running routinely with ~40-mA, 1-MW beams, the SNS linac is fed from the ion source with ~1ms long, ~50-mA H beam pulses at 60 Hz. This requires the daily extraction of ~230 C of H ions, which exceeds the routine daily production of other H accelerator sources by almost an order of magnitude. The source service cycle has been extended from 2, to 3, to 4, and up to 5.6 weeks without age-related failures. The 7-9 kC of H ions delivered in single service cycles exceed the service cycle yields of other accelerator sources. The paper discusses the findings as well as the issues and their mitigations, which enabled the simultaneous increase of the beam current, the duty factor, the availability, and the service cycle.
 
 
WEP276 Development of an Advanced Barium Ion Source for a Laser-Induced-Fluorescence (LIF) Diagnostic on the Paul Trap Simulator Experiment (PTSX) ion, vacuum, diagnostics, plasma 1996
 
  • H. Wang, R.C. Davidson, P. Efthimion, E.P. Gilson, R. M. Majeski
    PPPL, Princeton, New Jersey, USA
 
  The Paul Trap Simulator Experiment (PTSX) is a cylindrical Paul trap that simulates the nonlinear transverse dynamics of intense charged particle beam propagation through an equivalent kilometers-long magnetic alternating-gradient (AG) focusing system. Understanding the collective dynamics and instability excitations of intense charged particle beam is of great importance for a wide variety of accelerator applications. Since the optical spectrum of barium ions is better-suited to the Laser-Induced-Fluorescence (LIF) diagnostic than cesium ions, a barium ion source is being developed to replace the cesium ion source. A Laser-Induced-Fluorescence diagnostic will be able to provide in situ measurement of the radial density profile and, ultimately, the velocity distribution function of the intense charged particle beam. The new barium ion source is expected to increase the ion density as well as minimize the number of neutral barium atoms which enter the PTSX vacuum chamber. The design includes an ionizer, an extractor, and a neutral gas filter scheme. Initial test results of this new barium ion source will be presented.  
 
WEP293 Design and Fabrication of the Lithium Beam Ion Injector for NDCX-II ion, optics, vacuum, solenoid 2032
 
  • J.H. Takakuwa, J.-Y. Jung, J.T. Kehl, J.W. Kwan, M. Leitner, P.A. Seidl, W.L. Waldron
    LBNL, Berkeley, California, USA
  • A. Friedman, D.P. Grote, W. M. Sharp
    LLNL, Livermore, California, USA
 
  Funding: This work is performed under the auspices of the U.S. Department of Energy by LBNL under contract DE-AC02-05CH11231.
A 130 keV injector is developed for the NDCX-II facility. It consists of a 10.9 cm diameter lithium doped alumina-silicate ion source heated to ~1300 °C and 3 electrodes. Other components include a segmented Rogowski coil for current and beam position monitoring, a gate valve, pumping ports, a focusing solenoid, a steering coil and space for inspection and maintenance access. Significant design challenges including managing the 3-4 kW of power dissipation from the source heater, temperature uniformity across the emitter surface, quick access for frequent ion source replacement, mechanical alignment with tight tolerance, and structural stabilization of the cantilevered 27” OD graded HV ceramic column. The injector fabrication is scheduled to complete by May 2011, and assembly and installation is scheduled to complete by the beginning of July.
 
 
THP027 Status and Development of a Proton FFAG Accelerator at KURRI for ADSR Study injection, proton, linac, ion 2172
 
  • Y. Kuriyama, Y. Ishi, J.-B. Lagrange, Y. Mori, R. Nakano, T. Planche, T. Uesugi, E. Yamakawa
    KURRI, Osaka, Japan
  • Y. Niwa, K. Okabe, I. Sakai
    University of Fukui, Faculty of Engineering, Fukui, Japan
 
  In Kyoto University Research Reactor Institute (KURRI), the fixed-field alternating gradient (FFAG) proton accelerator has been constructed to make an experimental study of accelerator driven sub-critical reactor (ADSR) system with spallation neutrons produced by the accelerator. The world first ADSR experiment has been carried out in March of 2009. The proton FFAG accelerator consists of three FFAG rings; injetor (spiral sector FFAG), booster(radial sector FFAG) and main ring(radial sector FFAG), respectively. In March 2010, the experiment conducted with a thorium-loaded accelerator driven system using the proton FFAG accelerator has also been carried out. In order to increase the beam intensity of the proton FFAG accelerator, a new injector with H ions is under construction. In this scheme, H ions accelerated up to the energy of 11 MeV with a linac are injected into the main ring with charge-exchange injection. In this paper, the details of ADSR experiments with the proton FFAG accelerator at KURRI, and also the R&Ds of the accelerator will be presented.