TUO2C  —  Commissioning, Operations and Performance   (28-Sep-10   14:15—16:45)

Chair: H. Hotchi, JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken

Paper Title Page
TUO2C01 Spallation Neutron Source Operational Experience at 1 MW 377
 
  • J. Galambos
    ORNL, Oak Ridge, Tennessee
 
 

The Spallation Neutron Source (SNS) has been operating at the MW level for about one year. Experience in beam loss control and machine activation at this power level will be presented. Also experience with machine protection systems will be reviewed, which are critical at this power level. One of the most challenging aspect of high power operation has been attaining high availability, and these issues will also be discussed.

 

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TUO2C02 High Power Operational Experience at ISIS 381
 
  • D.J.S. Findlay
    STFC/RAL/ISIS, Chilton, Didcot, Oxon
 
 

At present ISIS is the world's most productive spallation neutron source. For the last two years (i.e. since 2008) ISIS has been running a second target station (TS-2) optimised for cold neutron production while continuing to run the first target station (TS-1) which began operating in 1984. The ISIS 800 MeV proton synchrotron cycling at 50 Hz produces a total beam power of 0.2 MW which is split between the first target station (TS-1) and TS-2, 40 Hz to TS-1 and 10 Hz to TS-2. The first two years of the new two-target-station operational regime are described.

 

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TUO2C03 Recent Operational Experience at the LANSCE Facility 386
 
  • L. Rybarcyk
    LANL, Los Alamos, New Mexico
 
 

The Los Alamos Neutron Science Center (LANSCE) consists of a pulsed 800-MeV room-temperature linear accelerator and an 800-MeV accumulator ring. It simultaneously provides H+ and H- beams to several user facilities that have their own distinctive requirements, e.g. intensity, chopping pattern, duty factor, etc.. This multi-beam operation presents challenges both from the standpoint of meeting the individual requirements but also achieving good overall performance for the integrated operation. This presentation will touch on various aspects of more recent operations including the some of these challenges.

 

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TUO2C04 Measuring Correlations Between Beam Loss and Residual Radiation in the Fermilab Main Injector 391
 
  • B.C. Brown, G.H. Wu
    Fermilab, Batavia
 
 

In order to control beam loss for high intensity operation of the Fermilab Main Injector, electronics has been implemented to provide detailed loss measurements using gas-filled ionization monitors. Software to enhance routine operation and studies has been developed and losses are logged for each acceleration cycle. A systematic study of residual radiation at selected locations in the accelerator tunnel have been carried out by logging residual radiation at each of 142 bar-coded locations. We report on fits of the residual radiation measurements to half-life weighted sums of the beam loss data using a few characteristic lifetimes. The data are now available over a multi-year period including residual radiation measurements repeated multiple times during two extended facility shutdown periods. Measurement intervals of a few weeks combined with variable delays between beam off time and the residual measurement permits sensitivity to lifetimes from hours to years. The results allow planning for work in radiation areas to be based on calibrated analytic models.

 

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TUO2C05 Operation Performance of the LHC Collimation 395
 
  • S. Redaelli, R.W. Assmann, R. Bruce, A. Rossi, D. Wollmann
    CERN, Geneva
 
 

The collimation system of the CERN Large Hadron Collider (LHC) was built to handled 360 MJ stored in the LHC beams and is one of the most advanced cleaning system built for accelerators. It consist of 88 ring collimators of various designs and materials, for a total of 352 degrees of freedom (4 motors per collimators), that provide a multi-stage cleaning of beam halo as well as a crucial role for the LHC machine protection. Collimator can be moved with functions of time to guarantee the optimum settings during energy ramp and betatron squeeze. The system has been commissioned with beam for the 3.5 TeV LHC run and has ensured a safe operation, providing a close to nominal cleaning performance in the initial LHC operational phases. In this paper, the setup procedure and the setting validation techniques are presented, the operational aspects and challenges are reviewed and the system performance is discussed.

 

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TUO2C06 Beam Loss and Residual Dose at 100kW User Operation in the J-PARC Accelerator 400
 
  • K. Yamamoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
 
 

The accelerator facilities in J-PARC have been commissioned since January 2007. According to the progress of beam commissioning and construction of accelerators and experimental facilities, operational beam power becomes larger. The RCS produces 120kW beam to MLF and the MR provides 50kW beam to Neutrino target. In such high intensity operation, Linac ACS section, RCS injection and arc section, and MR collimator section become slightly higher residual dose area. We try to improve these losses before it is too late.

 

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