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O'Hara, J. F.

Paper Title Page
MOPAS046 LANSCE Radiation Resistant Water Manifold Retrofit for DC Magnets 536
 
  • M. J. Borden, J. F. O'Hara, E. M. Perez, B. J. Roller, V. P. Vigil, L. S. Walker
    LANL, Los Alamos, New Mexico
 
  Funding: Work supported by the United States Department of Energy, National Nuclear Security Agency, under contract DE-AC52-06NA25396

Large maintenance dose burdens have necessitated the development of radiation resistant water manifolds for use on DC magnets in the Proton Storage Ring, at the Los Alamos Neutron Science Center (LANSCE) accelerator. This paper will describe dose measurements and the mechanical design of radiation resistant water manifolds used in PSR.

 
MOPAS047 LANSCE Fail Safe Radiation Shutter Design for Isotope Production Facility 539
 
  • M. J. Borden, C. A. Chapman, C. T. Kelsey, J. F. O'Hara, J. Sturrock
    LANL, Los Alamos, New Mexico
 
  Funding: Work supported by the United States Department of Energy, National Nuclear Security Agency, under contract DE-AC52-06NA25396

Dose rate modeling and post irradiation measurements of the Isotope Production Facility beamline, at the Los Alamos Neutron Science Center (LANSCE) accelerator, have determined that a radiation shielding shutter is required to protect personnel from shine from irradiated targets for routine beam tunnel entries. This paper will describe radiation dose modeling, shielding calculations and the failsafe mechanical shutter design.

 
TUODAB02 Electron Cloud Generation and Trapping in a Quadrupole Magnet at the LANL PSR 828
 
  • R. J. Macek, J. E. Ledford, R. J. Macek
    TechSource, Santa Fe, New Mexico
  • M. J. Borden, A. A. Browman, R. C. McCrady, J. F. O'Hara, L. Rybarcyk, T. Spickermann, T. Zaugg
    LANL, Los Alamos, New Mexico
  • M. T.F. Pivi
    SLAC, Menlo Park, California
 
  Funding: Work supported by DOE SBIR Grant No. DE-FG02-04ER84105 and CRADA No. LA05C10535 between TechSource, Inc. and the Los Alamos National Laboratory.

Recent beam physics studies on the two-stream e-p instability at LANL proton storage ring (PSR) have focused on the role of the electron cloud generated in quadrupole magnets where electrons, which seed beam-induced multipacting, are expected to be largest due to grazing angle losses from the beam halo. A new diagnostic to measure electron cloud formation and trapping in a quadrupole magnet has been developed, installed, and successfully tested at PSR. Experimental results will be presented on various characteristics of electron cloud obtain from experiments using this diagnostic and compared with simulations. Results include data on flux and energy spectra of electrons striking the vacuum chamber, the line density and lifetime of electrons trapped in the quadrupole after the beam has been extracted as well as evidence regarding electrons ejected from the magnet during passage of the proton beam.

 
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FRPMS051 Proposed Beam Diagnostics Instrumentation for the LANSCE Refurbishment Project 4099
 
  • J. D. Gilpatrick, B. Blind, M. J. Borden, J. L. Erickson, M. S. Gulley, S. S. Kurennoy, R. C. McCrady, J. F. O'Hara, M. A. Oothoudt, C. Pillai, J. F. Power, L. Rybarcyk, F. E. Shelley
    LANL, Los Alamos, New Mexico
 
  Funding: *Work supported by the U. S. Department of Energy.

Presently, the Los Alamos National Laboratory is in the process of planning a refurbishment of various sub-systems within its Los Alamos Neutron Science Center accelerator facility. A part of this LANSCE facility refurbishment will include some replacement of and improvement to existing older beam diagnostics instrumentation. While plans are still being discussed, some instrumentation that is under improvement or replacement consideration are beam phase and position measurements within the 805-MHz side-coupled cavity linac, slower wire profile measurements, typically known as wire scanners, and possibly additional installation of fast ionization-chamber loss monitors. This paper will briefly describe the requirements for these beam measurements, what we have done thus far to answer these requirements, and some of the technical issues related to the implementation of these instrumentation.

 
FRPMS054 PSR Electron Cloud Detector and Suppressor Mechanical Design and Fabrication 4117
 
  • J. F. O'Hara, M. J. Borden, A. A. Browman, N. A. Gillespie, D. Martinez, K. G. McKeown, F. R. Olivas
    LANL, Los Alamos, New Mexico
  • J. E. Ledford, R. J. Macek
    TechSource, Santa Fe, New Mexico
 
  Funding: Work supported by DOE SBIR Grant No. DE-FG02-04ER84105 and CRADA No. LA05C10535 between TechSource, Inc. and the Los Alamos National Laboratory.

In order to better understand the two stream e-p instability issue in the LANSCE Proton Storage Ring, a new diagnostic instrument has been developed to measure the electron cloud formation and trapping in a quadrupole magnet at the LANSCE, PSR. The device called the Electron Cloud Detector (ECD) was fabricated and has successfully been installed in the PSR. Along with the Electron Cloud Detector, an additional device was developed to manipulate electrons ejected from the quadrupole and allow additional information to be obtained from ECD measurements. This paper will discuss the mechanical design and fabrication issues encountered during the course of developing both devices.

 
FRPMS055 LANSCE Prototype Beam Position and Phase Monitor (BPPM) Mechanical Design 4123
 
  • J. F. O'Hara, M. J. Borden, D. C. Bruhn, J. L. Erickson, J. D. Gilpatrick, S. S. Kurennoy
    LANL, Los Alamos, New Mexico
 
  Funding: Work supported by United States Department of Energy

A prototype Beam Position and Phase Monitor (BPPM) beam line device is being designed to go in the LANSCE 805-MHz linac. The concept is to install two beam line devices in locations where their measurements can be compared with older existing Delta-T loop and wire scanner measurements. The plan is to install two devices so that transverse position, angular trajectory, as well as central beam phase and energy will be measured. The mechanical design will combine features from previous LANL designs that were done for the LANSCE Isotope Production Facility, LANSCE Switchyard project, and those done for the SNS linac. This paper will discuss the mechanical design and fabrication issues encountered during the course of developing the BPPM.