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Paper Title Other Keywords Page
MPPT021 Magnetic Measurement System for the NSLS Superconducting Undulator Vertical Test Facility undulator, vacuum, multipole, instrumentation 1730
  • D.A. Harder, G. Rakowsky, J. Skaritka
    BNL, Upton, Long Island, New York
  One of the challenges of small-gap superconducting undulators is measurement of magnetic fields within the cold bore to characterize the device performance and to determine magnetic field errors for correction or shimming, as is done for room-temperature undulators. Both detailed field maps and integrated field measurements are required. This paper describes a 6-element, cryogenic Hall probe field mapper for the NSLS Superconducting Undulator Vertical Test Facility (VTF). The probe is designed to work in an aperture only 3 mm high. A pulsed-wire insert is also being developed, for visualization of the trajectory, for locating steering errors and for determining integrated multi-pole errors. The pulsed-wire insert will be interchangeable with the Hall probe mapper. The VTF and the magnetic measurement systems can accommodate undulators up to 0.4 m in length.

*J. Skaritka et al., MEDSI’04.

WPAE037 Deformation Monitoring of the Spallation Neutron Source (SNS) Tunnels monitoring, SNS, alignment, target 2509
  • J.J. Error, D.R. Bruce, J.J. Fazekas, S.A. Helus, J.R. Maines
    ORNL, Oak Ridge, Tennessee
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy.

The SNS Project is a 1.4 MW accelerator-based neutron source located at Oak Ridge National Laboratory in Oak Ridge, Tennessee. For shielding purposes, a 17 foot berm of native soil has been constructed on top of the accelerator tunnel system. This backfill has caused ongoing settlement of the tunnels. The settlement has been monitored by the SNS Survey and Alignment Group at regular intervals, in order to discover the patterns of deformation, and to determine when the tunnels will be stable enough for precise alignment of beam line components. The latest monitoring results indicate that the settlement rate has significantly decreased. This paper discusses the techniques and instrumentation of the monitoring surveys, and provides an analysis of the results.

WPAE042 Beam Loss and Residual Activation Trending beam-losses, linac, SNS, focusing 2726
  • G.W. Dodson, M. Giannella, A.T. Ruffin, T.L. Williams
    ORNL, Oak Ridge, Tennessee
  Funding: This work was supported by SNS through UT-Batelle, LLC, under contract DE-AC05-00OR22725 for the U.S. DOE. The SNS is a partnership of six national laboratories: Argonne, Brookhaven, Jefferson, Lawrence Berkeley, Los Alamos, and Oak Ridge.

The SNS Front End, Drift Tube Linac and most of the Coupled Cavity Linac have been operated during commissioning. Beam loss data were taken with differential Beam Current Monitors, and Beam loss Monitors during commissioning. Residual activation data were taken at various times during and after the run. An analysis of beam loss trending, beam loss monitor data and residual activation will be shown.

WPAE044 An Alignment of J-PARC Linac alignment, linac, target, synchrotron 2851
  • T. Morishita, H. Ao, T. Ito, A. Ueno
    JAERI/LINAC, Ibaraki-ken
  • K. Hasegawa
    JAERI, Ibaraki-ken
  • M. Ikegami, C. Kubota, F. Naito, E. Takasaki, H. Tanaka, K. Yoshino
    KEK, Ibaraki
  J-PARC linear accelerator components are now being installed in the accelerator tunnel, whose total length is more than 400 m including the beam transport line to RCS (Rapid Cycling Synchrotron). A precise alignment of accelerator components is essential for a high quality beam acceleration. In this paper, planned alignment schemes for the installation of linac components, the fine alignment before beam acceleration, and watching the long term motion of the building are described. Guide points are placed on the floor, which acts as a reference for the initial alignment at the installation and also as a relay point for the long surveying network linking at the fine alignment. For a straight line alignment, the wire position sensor is placed on the offset position with respect to the beam center by a target holder, then a single wire can cover the accelerator cavities and the focusing magnets at the DTL-SDTL section (120m). The hydrostatic levering system (HLS) is used for watching the floor elevation (changes) over the long period.  
WOPB002 Symmetries and Einstein vacuum, background, coupling, focusing 217
  • M. Kobayashi
    KEK, Ibaraki
  After brief survey of influence of Einstein on current particle physics, fundamental symmetry between particles and antipaticles will be discussed. Existence of antiparticles is an important outcome of special relativity and quantum mechanics and disappearance of antiparticles from the present universe is one of the mysteries in Big Bang cosmology based on the Einstein equation. Remarkable progress has been made recently in the studies on the violation of symmetry between particles and antiparticles with the use of a new type of accelerator. Some of their achievements will be reported.  
RPAT071 Digital Beam Position Monitor for the Happex Experiment instrumentation, controls, monitoring, linac 3841
  • S.R. Kauffman, H. Dong, A. Freyberger, L. Kaufman, J. Musson
    Jefferson Lab, Newport News, Virginia
  Funding: This work was supported by DOE contract No. DE-AC05-84ER40150.

The proposed HAPPEX experiment at CEBAF employs a three cavity monitor system for high-precision (1 mm), high-bandwidth (100 kHz) position measurements. This is performed using a cavity triplet consisting of two TM110-mode cavities (one each for X and Y planes) combined with a conventional TM-010-mode cavity for a phase and magnitude reference. Traditional systems have used the TM010 cavity output to directly down convert the BPM cavity signals to base band. The Multi-channel HAPPEX digital receiver simultaneously I/Q samples each cavity and extracts position using a CORDIC algorithm. The hardware design consists of a digital receiver daughter board and digital processor motherboard that resides in a VXI crate. The daughter board down converts 1.497 GHz signals from the TM010 cavity and X and Y signals from the TM110 cavities to 4 MHz, and extracts the quadrature digital signals. The motherboard processes this data and computes beam intensity and X-Y positions with a resolution of one mm, 100 kHz output bandwidth, and overall latency of ten microseconds. The results are available in both analog and digital format.

FPAE005 Characteristics of Injected Beam at HIMAC Synchrotron injection, resonance, simulation, synchrotron 952
  • T.H. Uesugi, T. Furukawa, K. Noda, S. Shibuya
    NIRS, Chiba-shi
  At the HIMAC synchrotron, we have carried out the tune survey with the lifetime measurement in order to obtain the high intensity. Under the relatively high intensity, it was observed that a part of the circulating beam was lost due to the coherent oscillation in both the horizontal and the vertical direction. Taking account of the tune shift and spreads, the working point was optimized so as to avoid resonance line. We will describe the experimental result.