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SUPB037 The Development of Timing Control System for RFQ controls, rfq, EPICS, proton 89
 
  • J.N. Bai, S. Xiao, T.G. Xu, L. Zeng
    IHEP, Beijing, People's Republic of China
 
  A Timing control system based on VME configuration is developed to meet the need of 3.5 MeV RFQ. An EPICS driver is provided to control its work. The timing control system satisfies request after examination. In the future, it will be used in the machine running. This paper introduces the Timing control hardware, VME interface, EPICS driver for Timing control system and MEDM operator interface.  
 
MOPB051 Changing Attitude to Radiation Hazards and Consequent Opportunities for LINAC Applications radiation, linac, electron, status 288
 
  • Y. Socol
    Falcon Analytics, Netanya, Israel
 
  High-energy LINACs unavoidably yield ionizing radiation. This fact makes them subject to strict regulations and considerably limits applications. During the last two decades the attitude to ionizing radiation hazards seems to become more balanced, as opposed to "radiophobia" of the Cold-War era. Scientifically, the linear no-threshold (LNT) model of radiation damage is more and more questioned. Moreover, the hypotheses of radiation hormesis - beneficial effect of low-dose radiation - is studied. While this scientific debate has not yet given fruit regarding radiation regulation and policy, we may expect this in near to middle term. Namely, the ALARA (as low as reasonably achievable) demand is anticipated to be substituted by some tolerance level, which in turn is anticipated to be very high according to the present standards. The presentation will review the present status of the radiation-hazard debate, and outline anticipated opportunities for LINAC applications, like compact designs and wider industrial outreach.  
 
TUPB082 Beam Loss Track Measurements by a Fast Trigger Scheme in J-PARC Linac linac, proton, simulation, neutron 663
 
  • H. Sako, T. Maruta, A. Miura
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
 
  Funding: Work partially supported by Grant-in-Aid for Challenging Exploratory Research
In J-PARC Linac, highest beam loss has been observed at the ACS (Annular-Coupled Structure linac) section. The primary source of the beam loss is considered to be H0 produced by an interaction of H beams with remnant gas. The H0 hits the beam duct, converted to H+, and escapes from the beam duct. To detect the H+'s and estimate the absolute magnitude of the beam loss, we constructed a detector system, which consists of 6 planes of hodoscopes made of 16 scintillation fibers with 64 x 64 mm2 area. The scintillation light is measured by multi-anode photomultipliers. In the ACS section, two planes to measure horizontal positions are installed, and at about 1 m downstream positions, two planes for horizontal measurements and two for vertical measurements are placed. We will reconstruct charged particles passing through all the 6 planes, and measure the velocity by time-of-flight and energy loss to identify particle species. We present new measurements since the recovery of the J-PARC after the earthquake started in April 2012 by a new fast trigger scheme using dynode signals of photomultipliers in order to improve signal-to-noise ratios.
 
 
THPB013 Diagnostics Tools for Beam Halo Investigation in SNS Linac emittance, linac, laser, diagnostics 873
 
  • A.V. Aleksandrov, W. Blokland, Y. Liu, C.D. Long, A.P. Zhukov
    ORNL, Oak Ridge, Tennessee, USA
 
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy.
Uncontrolled beam loss is the major concern in operation of a high intensity hadron linac. A low density cloud of particles with large oscillation amplitudes, so called halo, can form around the dense regular beam core. This halo can be direct or indirect cause of beam loss. There is an experimental evidence of halo growing in SNS linac and limiting further reduction of beam loss. A set of tools is being developed for detecting of the halo and investigating its origin and dynamics. The set includes high resolution emittance measurements in the injector, laser based emittance measurements at 1 GeV, and high resolution profile measurements along the linac. We will present our experience with useful measurement techniques and data analysis algorithms as well as current understanding of the halo dynamics in SNS linac.
 
 
THPB081 The Development of Timing Control System for RFQ controls, rfq, EPICS, proton 1014
 
  • J.N. Bai, S. Xiao, T.G. Xu, L. Zeng
    IHEP, Beijing, People's Republic of China
 
  Timing control system based on VME configuration is developed to meet the need of 3.5 MeV RFQ. An EPICS driver is provided to control its work. The timing control system satisfies request after examination. In the future, it will be used in the machine running. This paper introduces the Timing control hardware, VME interface, EPICS driver for Timing control system and MEDM operator interface.