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ion-source

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MOPAN040 Comparative Study on Lifetime of Stripper Foil using 650keV H- Ion Beam target, ion, synchrotron, linac 245
 
  • A. Takagi
  • C. S. Feigerle
    University of Tennessee, Knoxville, Tennessee
  • Y. Irie
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • M. A. Plum, R. W. Shaw
    ORNL, Oak Ridge, Tennessee
  • I. Sugai, Y. Takeda
    KEK, Ibaraki
  Funding: This work is supported by the Japan Society for the Promotion of Science, under contract No. 18540303.

Thick carbon stripper foils of >300 μg/cm2 will be used as a stripping of H-ion beam for 3GeV Rapid Cycling Synchrotron (3GeV-RCS) of the J-PARC. The carbon foils with long lifetime even at >1800 K are required. For this purpose, we have developed a new irradiation system for the lifetime measurement using high current pulsed and dc H- beams of the KEK Cockcroft-Walton accelerator. These high power 650keV H- Ion beams can simulate the high energy deposition in carbon stripper foils at the J-PARC RCS. An automatic data acquisition system is also developed for recording the data of foil temperature and irradiated beam current. The Hybrid Boron mixed Carbon (HBC) stripper foils, which are developed at KEK are irradiated by high current H- ion beam up to 2000 K. A few SNS-diamond and commercially available carbon (CM) foils are also tested for comparing with HBC-foils. The results of the lifetime measurement of HBC and SNS-diamond including CM stripper foils are reported.

 
 
MOPAN057 LabVIEW and MATLAB-Based Virtual Control System for Virtual Prototyping of Cyclotron controls, cyclotron, ion, simulation 281
 
  • Y. Q. Xiong
  • M. Fan, B. Qin, M. J. Wu, J. Yang
    HUST, Wuhan
  Funding: This work is supported by National Nature Science Foundation of China under Grant 10435030

A virtual control system designed to control and monitor the process of a cyclotron virtual prototyping is presented in this paper. Based on the feature of cyclotron, a distributed control structure is proposed according to the knowledge of software engineering. LabVIEW is employed to develop human machine interface(HMI), sequential control, safety interlock, and MATLAB is used to implement analysis and simulation. Dynamic data exchange (DDE) supported by Win32 Platform SDK is adopted to process data exchanging by a Server/Client mode. Any additional functions can be extended easily in this system in future.

 
 
TUPAN009 Performance of the SARAF Ion Source ion, proton, emittance, plasma 1407
 
  • K. Dunkel
  • F. Kremer, C. Piel
    ACCEL, Bergisch Gladbach
  Since October 2006 an ECR ion source is under operation at SOREQ. The source will be used to generate protons and deuterons in a current range from 0.04 to 5 mA. The paper will present operation results as current, emittance and stability measurements. Further the influence of variables as solenoid fields, RF power and gas flow will be described. A short description of the attached beam transport system and beam diagnostic system will be given as well.  
 
TUPAN011 Beam Operation of the SARAF Light Ion Injector rfq, diagnostics, ion, proton 1410
 
  • C. Piel
  • K. Dunkel, M. Pekeler, H. Vogel, P. vom Stein
    ACCEL, Bergisch Gladbach
  In beginning of 2007 the installation of the first stage of SARAF has been finalized. The system consists out of an ECR ion source, a low energy beam transport system, a four rod RFQ, a medium energy transport system and a superconducting module housing 6 half resonators and three superconducting solenoids. This injector will be characterized with a diagnostic plate. The installation allows continuous measurement of beam charge, position and phase. The diagnostic plate in addition provides a beam halo monitor, vertical and horizontal slit and wire systems, a slow and a fast faraday cup, which can only be used in pulsed operation. The paper will describe the status of commissioning, including results of the site acceptance test of major components.  
 
TUPAN018 The Frankfurt Funneling Experiment rfq, simulation, ion, emittance 1431
 
  • N. Mueller
  • U. Bartz, D. Ficek, P. Fischer, P. Kolb, A. Schempp, J. Thibus, M. Vossberg
    IAP, Frankfurt am Main
  Funneling is a procedure to multiply beam currents at low energies in several stages. The Frankfurt Funneling Experiment is a prototype of such a stage. Our experiment consists of two ion sources, a Two-Beam RFQ accelerator, a funneling deflector and a beam diagnostic system. The two beams from the ion sources are injected into two RFQ beam lines. These two beams are accelerated in a Two-Beam RFQ and combined to one beam axis with a funneling deflector. The last parts of the RFQ electrodes have been replaced to achieve a 3d focus at the crossing point of the two beam axis. The newly designed multigap deflector is adapted to the optimized funneling section. First results and beam measurements with the new setup will be presented.  
 
TUPAN064 Use of Solidified Gas Target to Laser Ion Source ion, laser, target, plasma 1535
 
  • J. Tamura
  • T. Kanesue
    Kyushu University, Fukuoka
  • M. Okamura
    BNL, Upton, Long Island, New York
  We examined a laser produced neon plasma as part of a future laser ion source. The ion source is capable of generating highly ionized particles and high intensity beams by irradiating a solid target with a pulsed laser. Rare gases, which are in gas state at room temperature, need to be cooled to solid targets for laser irradiation. We generated solid neon targets by equipping our laser ion source chamber with a cryogenic cooler. This method will generate high current rare gas beams.  
 
TUPAN110 On Feasibility Study of 8 MeV H- Cyclotron to Charge the Electron Cooling System for HESR cyclotron, extraction, ion, electron 1631
 
  • N. Yu. Kazarinov
  • A. I. Papash
    NASU/INR, Kiev
  • V. V. Parkhomchuk
    BINP SB RAS, Novosibirsk
  A compact cyclotron to accelerate negative Hydrogen ions up to 8 MeV is considered the optimal solution to the problem of charging the high voltage terminal of the Electron Cooling System for High Energy Storage Ring at GSI (HESR Project, Darmstadt). Physical as well as technical parameters of the accelerator are estimated. Different types of commercially available cyclotrons are compared as a possible source of a 1 mA H- beam for HESR. An original design based on the application of well-established technical solutions for commercial accelerators is proposed.  
 
TUPAN111 Status Report on the RAL Front End Test Stand rfq, ion, linac, emittance 1634
 
  • J. K. Pozimski
  • J. Alonso, R. Enparantza
    Fundacion Tekniker, Elbr (Guipuzkoa)
  • J. J. Back
    University of Warwick, Coventry
  • J. Bermejo
    Bilbao, Faculty of Science and Technology, Bilbao
  • Y. A. Cheng, S. Jolly, A. Kurup, P. Savage
    Imperial College of Science and Technology, Department of Physics, London
  • M. A. Clarke-Gayther, A. Daly, D. C. Faircloth, A. P. Letchford
    STFC/RAL/ISIS, Chilton, Didcot, Oxon
  • C. Gabor, D. C. Plostinar
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon
  • J. Lucas
    Elytt Energy, Madrid
  High power proton accelerators (HPPAs) with beam powers in the several megawatt range have many applications including drivers for spallation neutron sources, neutrino factories, waste transmuters and tritium production facilities. The UK's commitment to the development of the next generation of HPPAs is demonstrated by a test stand being constructed in collaboration between RAL, Imperial College London and the University of Warwick. The aim of the RAL Front End Test Stand is to demonstrate that chopped low energy beams of high quality can be produced and is intended to allow generic experiments exploring a variety of operational regimes. This paper describes the status of the RAL Front End Test Stand which consists of five main components: a 60 mA H- ion source, a low energy beam transport, a 324 MHz Radio Frequency Quadrupole accelerator, a high speed beam chopper and a comprehensive suite of diagnostics. The aim is to demonstrate production of a 60 mA, 2 ms, 50 pps, chopped H- beam at 3 MeV.  
 
TUPAS003 Experimental Results on Multi-Charge-State LEBT Approach ion, emittance, heavy-ion, proton 1658
 
  • A. Kondrashev
  • A. Barcikowski, B. Mustapha, P. N. Ostroumov, R. H. Scott, S. I. Sharamentov
    ANL, Argonne, Illinois
  • N. Vinogradov
    Northern Illinois University, DeKalb, Illinois
  Funding: This work was supported by the U. S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC-02-06CH11357.

A multi-charge-state injector for high-intensity heavy-ion LINAC is being developed at ANL. The injector consists of an all-permanent magnet ECR ion source, a 100 kV platform and a Low Energy Beam Transport (LEBT). The latter comprises two 60-degree bending magnets, electrostatic triplets and beam diagnostics stations. The first results of beam measurements in the LEBT will be presented.

 
 
TUPAS044 Design of a High Temperature Oven for an ECR Source for the Production of Uranium Ion Beams ion, injection, plasma, cyclotron 1742
 
  • T. J. Loew
  • S. R. Abbott, M. L. Galloway, D. Leitner, C. M. Lyneis
    LBNL, Berkeley, California
  VENUS is the superconducting electron cyclotron resonance (ECR) ion source at the Lawrence Berkeley National Lab's 88-Inch Cyclotron. To generate neutral atoms for ionization, the source utilizes a resistively-heated high temperature oven that is located in a magnetic field of up to 4 Tesla and operates at temperatures up to about 2000°C. However, temperatures between 2100-2300°C are required to produce the desired 280eμA of high charge state uranium ion beams, and increased thermal and structural effects, combined with elevated chemical reactivity significantly reduce the oven's ability to operate in this envelope. The oven has been redesigned with higher thermal efficiency, improved structural strength and chemically compatible species in order to produce the desired high intensity, high charge state uranium beams. Aspects of the engineering development are presented.  
 
TUPAS045 Microwave Ion Source and Beam Injection for an Accelerator-driven Neutron Source ion, emittance, extraction, rfq 1745
 
  • J. H. Vainionpaa
  • R. Gough, M. D. Hoff, J. W. Kwan, B. A. Ludewigt, M. J. Regis, J. G. Wallig, R. P. Wells
    LBNL, Berkeley, California
  Funding: Supported by Office of Science, of the U. S. Department of Energy under Contract No. DE-AC02-05CH11231 and by the U. S. Department of Homeland Security under contract No. HSHQBP-05-X-00033.

An over-dense microwave driven ion source capable of producing deuterium (or hydrogen) beams at 100-200 mA/cm2 with an atomic fraction > 90% was designed as a part of an Accelerator Driven Neutron Source (ADNS). The ion source was tested with an electrostatic low energy beam transport section (LEBT) and measured emittance data was compared to PBGUNS simulations. In our design a 40 mA D+ beam is produced from a 6 mm diameter aperture using a 60 kV extraction voltage. The LEBT section consists of 5 electrodes arranged to form 2 Einzel lenses that focus the beam into the RFQ entrance. To create the ECR condition, 2 induction coils are used to generate a ~875 Gauss magnetic field on axis inside the source chamber. To prevent HV breakdown in the LEBT, a magnetic field clamp is necessary to minimize the field in this region. The microwave power is matched to the plasma by an autotuner. A significant improvement in the atomic fracion of the beam was achieved by installing a boron nitride liner inside the ion source

 
 
TUPAS063 A New Bunching Scheme for Increasing the LANSCE WNR Peak Beam Current simulation, ion, bunching, linac 1799
 
  • L. Rybarcyk
  • J. T.M. Lyles
    LANL, Los Alamos, New Mexico
  Funding: This work is supported by the U. S. Department of Energy, Contract DE-AC52-06NA25396.

The LANSCE linac simultaneously provides both H+ and H- beams to several user facilities. The Weapons Neutron Research (WNR) user facility is configured to accept the H- beam with a typical pulse pattern of one linac micro-pulse every 1.8 microseconds. To produce this pulse spacing a slow-wave chopper located in the 750 keV injector beam transport is employed to intensity modulate the beam. The beam is subsequently bunched at both 16.77 MHz and 201.25 MHz prior to entering the 100 MeV drift tube linac. One downside of the chopping process is that the majority of the beam produced by the ion source during the WNR macro-pulses is discarded. By applying a longitudinal bunching action immediately following the ion source, simulations have shown that some of this discarded beam can be used to increase the charge in these micro-pulses. Recently, we began an effort to develop this buncher by superimposing 16.77 MHz RF voltage on one of the HVDC electrodes in the 80 kV column located inside H- Cockcroft-Walton dome. This paper describes the beam dynamics simulations, design and implementation of the rf hardware and the results of tests performed with the system.

 
 
TUPAS064 Helicon Plasma Generator-assisted H- Ion Source Development at Los Alamos Neutron Science Center plasma, ion, electron, permanent-magnet 1802
 
  • O. A. Tarvainen
  • R. Keller, G. Rouleau
    LANL, Los Alamos, New Mexico
  Funding: Work supported by the US Department of Energy under contract DE-AC52-06NA25396

The aim of the helicon plasma generator-assisted negative ion source development at Los Alamos Neutron Science Center (LANSCE) is to use high-density helicon plasmas for producing intense beams of H- ions. Our work consists of two development paths, construction of a hybrid ion source and replacement of the LANSCE surface converter ion source filaments by helicon plasma generators. The hybrid ion source is a combination of a long-life plasma cathode, sustained by a helicon plasma generator, with a stationary, pulsed main discharge (multi-cusp H- production chamber) directly coupled to each other. The electrons are transferred from the helicon plasma to the cusp-chamber by thermal flow process to ignite and sustain the main discharge. Replacing the filaments of the surface converter source by two helicon plasma generators is a low-cost solution, building upon the well-proven converter-type ion sources. Both development paths are aimed at meeting the beam production goals of the LANSCE 800 MeV linear accelerator refurbishment project. The design and status of both ion source types is discussed.

 
 
TUPAS075 The New LEBT for the Spallation Neutron Source Power Upgrade Project quadrupole, dipole, rfq, ion 1823
 
  • B. Han
  • M. P. Stockli
    ORNL, Oak Ridge, Tennessee
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U. S. Department of Energy.

Beam envelope calculations show that a solenoid-drift-(singlet quad)-(sector dipole)-(singlet quad)-drift-solenoid LEBT allows for transporting 65-kV, high-current H- beams with smaller beam radii than the initially-explored (doublet quad)-drift-(double-focusing dipole)-drift-solenoid configuration. In addition, it appears that the new configuration is more robust because it allows for perfect matching of the final beam parameters for broad ranges of the parameters describing the lattice and the input beam. Such a LEBT with a dipole (switching-) magnet is required to assure meeting the 99% ion source availability requirement after upgrading the power of the Spallation Neutron Source. The SNS power upgrade will roughly double the neutron flux by increasing the proton beam energy from 1 to 1.3 GeV and by increasing the LINAC beam peak current from 38 to 59 mA. Because the RFQ losses increase with beam current and emittance, the RFQ input current needs to be increased from 41 to 67 mA if the normalized emittance can be maintained at 0.2 mm-mrad, or to 95 mA if the emittance increases to 0.35 mm-mrad.

 
 
THPMS069 The New ORNL Multicharged Ion Research Facility Floating Beamline controls, ion, extraction, vacuum 3139
 
  • F. W. Meyer
  • M. R. Fogle, J. W. Hale
    ORNL, Oak Ridge, Tennessee
  Funding: Sponsored by the OBES and the OFES of the U. S. DOE under contract No. DE-AC05-00OR22725 with UT-Battelle, LLC. MRF was appointed through the ORNL Postdoctoral Research Associates Program administered jointly by ORISE and ORNL.

We report on the development and implementation of a new beam line floatable at up to -15 kV and injected by a 10 GHz CAPRICE ECR ion source at the ORNL Multicharged Ion Research Facility MIRF as part of a major facility upgrade project [1]. With the floating beamline operating at negative high voltage, and the ECR source at ground potential, intense dc beam deceleration into grounded experimental chambers to energies as low as a few eV/q is made possible. The primary application of these ion beams is to study fundamental collisional interactions [2] of multicharged ions with electrons, atoms, and surfaces. Design details of the floating beam line, including source extraction, deceleration optics and voltage isolation will be presented at the conference. The novel features of a LABVIEW-based supervisory control and data acquisition (SCADA) system developed for the floating beam line will be described as well.

[1]F. W. Meyer et al. "The ORNL MIRF Upgrade project," NIMB B242,71(2006).[2]F. W. Meyer,"ECR-Based Atomic Collisions Research at ORNL MIRF," in Trapping Highly Charged Ions: Fundamentals & Applications, Nova Sci. Pub., New York, 2000, pp. 117-164.

 
 
THPAS080 Initial Density Profile Measurements using a Laser-Induced Fluorescence Diagnostic in the Paul Trap Simulator Experiment ion, laser, diagnostics, plasma 3666
 
  • M. Chung
  • R. C. Davidson, P. Efthimion, E. P. Gilson, R. M. Majeski
    PPPL, Princeton, New Jersey
  Funding: Research supported by the U. S. Department of Energy.

Installation of a laser-induced fluorescence (LIF) diagnostic system has been completed and initial measurement of the beam density profile has been performed on the Paul trap simulator experiment (PTSX). The PTSX device is a linear Paul trap that simulates the collective processes and nonlinear transverse dynamics of an intense charged particle beam propagating through a periodic focusing quadrupole magnetic configuration. Although there are several visible transition lines for the laser excitation of barium ions, the transition from the metastable state has been considered first mainly because an operating, stable, broadband, and high-power laser system is available for experiments in this region of the red spectrum. The LIF system is composed of a dye laser, fiber optic cables, a line generator, which uses a Powell lens, collection optics, and a CCD camera system. Single-pass mode operation of the PTSX device is employed for the initial tests of the LIF system to make optimum use of the metastable ions. By minimizing the background light level, it is expected that enough signal to noise ratio can be obtained to re-construct the radial density profile of the ion beam.

 
 
FRXAB02 Review of Laser Driven Sources for Multi-charged Ions laser, ion, target, plasma 3761
 
  • M. Okamura
  • A. Kondrashev
    ANL, Argonne, Illinois
  Funding: This work was supported by the U. S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC-02-06CH11357

Laser beams have been widely used in the accelerator field for various applications. Here, we focus on ion beam production usage as an ion source. The laser ion source (LIS) already has about thirty years history and was developed for providing pulsed beam to synchrotrons. Since 2000 we have concentrated on the use of the high brightness of induced laser plasma to provide intense highly charged ions efficiently. To take advantage of the intrinsic density of the plasma, Direct Plasma Injection Scheme (DPIS) has been developed. The induced laser plasma has initial expanding velocity and can be delivered directly to the RFQ. The presentation will discuss general features of the laser ion sources and advantages of the DPIS.

 
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FRXAB03 Design, Construction and Commissioning of the SuSI ECR plasma, ion, sextupole, extraction 3766
 
  • P. A. Zavodszky
  • B. Arend, D. Cole, J. DeKamp, G. Machicoane, F. Marti, P. S. Miller, J. Moskalik, W. Nurnberger, J. Ottarson, J. Vincent, X. Wu, A. Zeller
    NSCL, East Lansing, Michigan
  Funding: This work was supported by the National Science Foundation under grant PHY-0110253.

An ECR ion source was constructed at the NSCL/MSU to replace the existing SC-ECRIS. This ECRIS operates at 18+14.5 GHz microwave frequencies and it is planned an upgrade to 24-28 GHz in the second phase of commissioning. A superconducting hexapole coil produces the radial magnetic field; the axial trapping is produced with six superconducting solenoids enclosed in an iron yoke to allow tuning the distance between the plasma electrode and resonant zone in the plasma. The plasma chamber of the ion source can be biased at +30 kV, the beam line at -30 kV. The voltage of the beam line vacuum pipe must be kept constant from the ECRIS to the point of full separation of the beam charge states near the image plane of the analyzing magnet. At this point, an insulator is used to increase the voltage up to zero value. The kinetic energy of the beam is decreased to 30 kV per unit charge after this point, as required for the injection in the Coupled Cyclotron Facility. To decrease the beam divergence, a focusing solenoid is installed after the vacuum pipe break. We report the details of the design, construction and initial commissioning results of this new ECIS.

 
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FROAAB02 Advanced RF-Driven H- Ion Sources at the SNS plasma, ion, extraction, emittance 3774
 
  • R. F. Welton
  • J. R. Carmichael, J. Carr, D. W. Crisp, R. H. Goulding, Y. W. Kang, N. P. Luciano, S. Murray, M. P. Stockli
    ORNL, Oak Ridge, Tennessee
  The power upgrade of the US Spallation Neutron Source* (SNS) will require substantially higher average H- beam current from the ion source than can be produced using the baseline source. H- currents of 70-100 mA with an RMS emittance of 0.20-0.35 mm mrad, respectively, and a ~7% duty-factor will have to be injected into the accelerator. We are, therefore, investigating several advanced ion source concepts based on RF-excited plasmas. We have designed and tested three inductively coupled ion sources featuring external antennas. First, a simple prototype source was developed based on a ceramic plasma chamber and no magnetic plasma confinement. Next, a source featuring an internal Faraday shield with integrated magnetic multicusp plasma confinement was investigated as well as an ion source based on an AlN plasma chamber and external multicusp confinement field. H- generation in each source is quantified and compared. Also, experiments investigating the possibility of using helicon-wave coupling were performed and are reported. Finally, an advanced elemental Cs collar and feed system was developed and tested with each source.

ORNL/SNS is managed by UT-Battelle, LLC, for the U. S. Department of Energy under contract DE-AC05-00OR22725

 
 
FROBAB01 Simulation-driven Optimization of Heavy-ion Production in ECR Sources ion, plasma, simulation, electron 3786
 
  • P. Messmer
  • D. L. Bruhwiler, D. W. Fillmore, P. J. Mullowney, K. Paul, A. V. Sobol
    Tech-X, Boulder, Colorado
  • D. Leitner, D. S. Todd
    LBNL, Berkeley, California
  Funding: Work supported by the U. S. DOE Office of Science, Office of Nuclear Physics, under grant DE-FG02-05ER84173.

Next-generation heavy-ion beam accelerators require a great variety of high charge state ion beams (from protons to uranium) with up to an order of magnitude higher intensity than demonstrated with conventional Electron Cyclotron Resonance (ECR) ion sources. Optimization of the ion beam production for each element is therefore required. Efficient loading of the material into the ECR plasma is one of the key elements for optimizing the ion beam production. High-fidelity simulations provide a means to understanding where along the interior walls the uncaptured metal atoms are deposited and, hence, how to optimize loading of the metal into the ECR plasma. We are currently extending the plasma simulation framework VORPAL with models to investigate effective loading of heavy metals into ECR ion sources via alternate mechanisms, including vapor loading, ion sputtering and laser ablation. Here we will present the models, simulation results of vapor loading and initial comparisons with experiments at the VENUS source at LBNL.

 
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FROBAB02 Inhomogeneities in Beams Extracted from ECR Ion Sources ion, simulation, sextupole, plasma 3789
 
  • J. W. Stetson
  • P. S. Spaedtke
    GSI, Darmstadt
  Funding: This work has been supported by National Science Foundation under grant PHY-0110253 and EURONS Contract 506065

An examination of heavy ion beam profiles using viewing targets and CCD cameras at both the GSI and NSCL shows highly structured patterns. These structures generally have a 3-fold symmetry reflecting the highly-magnetized nature of the ion formation within the plasma chamber. A program of experiment and three-dimensional modeling with KOBRA3d is continuing. Results of this program to date are discussed.

 
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