Author: Rouleau, G.
Paper Title Page
TUPMP053 Test Results of the Low-Stored-Energy -80 kV Regulator for Ion Sources at LANSCE 1369
 
  • J.T. Bradley III, L.N. Merrill, G. Rouleau, W. Roybal, G. Sanchez
    LANL, Los Alamos, New Mexico, USA
  
  Funding: Work supported by the U. S. Department of Energy.
The H− ion source at the LANSCE accelerator facility uses an 80 kV accelerating column to produce an H− ion beam. A regulated power supply maintains the source and support equipment racks at -80kV with respect to local ground. As the facility’s H− beam currents have been increased, voltage droop on the regulated -80 kV power supply has become one of the limiting factors on beam current. The previous regulator used a standard 120kV DC HV supply and a high power planar triode in series to regulate the voltage down to 80 kV and to stop the flow of current during an arcdown of the -80 kV accelerating column. In 2018 we devised a method of using a pair of standard, 50 kV capacitor charging supplies to produce the required 80 kV with minimal stored energy and significantly better voltage regulation over the beam pulse. This configuration has been tested on the Ion Source Test Stand and is being considered for installation on the main LANSCE linac. We will present the design, modeling and measured results of the new system as compared with the performance of the previous system. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP053  
About • paper received ※ 14 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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TUPTS009 Operating the SNS RF H− Ion Source with a 10% Duty Factor 1951
 
  • M.P. Stockli, M.E. Clemmer, S.M. Cousineau, B. Han, T.A. Justice, Y.W. Kang, S.N. Murray, T.R. Pennisi, C. Piller, R.F. Welton
    ORNL, Oak Ridge, Tennessee, USA
  • I.N. Draganic, R.W. Garnett, D. Kleinjan, G. Rouleau
    LANL, Los Alamos, New Mexico, USA
  • V.G. Dudnikov
    Muons, Inc, Illinois, USA
  • C. Stinson
    ORNL RAD, Oak Ridge, Tennessee, USA
  
  Funding: This work was performed at Oak Ridge National Laboratory under contract DE-AC05-00OR22725 and at Los Alamos National Laboratory under contract DE-AC52-06NA25396 for the U.S. Department of Energy.
The SNS (Spallation Neutron Source) (radio-frequency) RF-driven, H− ion source injects ~50 mA of H− beam into the SNS accelerator at 60 Hz with a 6% duty factor. It injects up to 7 A·hrs of H− ions during its ~14-week service cycles, which is an unprecedented lifetime for small-emittance, high-current pulsed H− ion sources. The SNS source also features unprecedented low cesium consumption and can be installed and started up in <10 h. Presently, the LANSCE (Los Alamos Neutron Science CEnter) accelerator complex in Los Alamos is fed by a filament-driven, biased converter-type H− source that operates with a high plasma duty factor of 10%. It needs to be replaced every 4 weeks with a ~4 day startup phase. The measured negative beam current of 16-18 mA falls below the desired 21 mA acceptance of LANSCE’s accelerator especially since the beam contains several mA of electrons. LANSCE and SNS are exploring the possibility of using the SNS RF H− source at LANSCE to increase the H− beam current and the ion source lifetime while decreasing the startup time. For this purpose, the SNS H− source has been tested at a 10% duty factor by operating it at 120 Hz with 840 µs plasma pulses generated with ~30 kW of 2 MHz RF power, and extracting ~25 mA around-the-clock for 28 days. This, and additional tests and other considerations are discussed in this paper. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS009  
About • paper received ※ 14 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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TUPTS071 H+ and H− Ion Beam Injectors at LANSCE: Beam Production Status and Planned Injector Upgrades 2087
 
  • I.N. Draganic, D. Kleinjan, G. Rouleau
    LANL, Los Alamos, New Mexico, USA
  
  The Los Alamos Neutron Science Center operates with two 750 keV Cockcroft-Walton accelerators for simultaneous injection of H+ and H− ion beams into a 800 MeV linear accelerator. The proton ion beam is produced using a duoplasmatron source and the H− ion beam is formed with a cesiated, multi-cusp-field, surface converter ion source. An overview of ion injector status, recent low energy beam transport line optimizations and ion source performance improvements will be presented. To reduce long term operational risks and to improve existing LANSCE beam production for all facility users, new injector upgrades are underway: 1) replacing the H+ CW injector with a Radio-Frequency Quadruple accelerator and 2) increasing H− ion beam brightness and extending source lifetime using the novel SNS RF negative ion source. The status of upgrade projects will be discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS071  
About • paper received ※ 14 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)