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Title: Synchrotron Light Interferometry at Jefferson Lab

The hyper-nuclear physics program at JLAB requires an upper limit on the RMS momentum spread of {delta}p/p < 3 x 10{sup -5}. The momentum spread is determined by measuring the beam width at a dispersive location (D {approx} 4m) in the transport line to the experimental halls. Ignoring the epsilon-beta contribution to the intrinsic beam size, this momentum spread corresponds to an upper bound on the beam width of {sigma}{sub beam} < 120 {micro}m. Typical techniques to measure and monitor the beam size are either invasive or do not have the resolution to measure such small beam sizes. Using interferometry of the synchrotron light produced in the dispersive bend, the resolution of the optical system can be made very small. The non-invasive nature of this measurement allows continuous monitoring of the momentum spread. Two synchrotron light interferometers have been built and installed at JLAB, one each in the Hall-A and Hall-C transport lines. The devices operate over a beam current range from 20 {micro}A to 120 {micro}A and have a spatial resolution of 10um. The structure of the interferometers, the experience gained during its installation, beam measurements and momentum spread stability are presented. The dependence of the measured momentum spreadmore » on beam current will be presented.« less
Authors:
; ; ;
Publication Date:
OSTI Identifier:
838709
Report Number(s):
JLAB-ACC-04-18; DOE/ER/40150-3269
TRN: US0501495
DOE Contract Number:
AC05-84ER40150
Resource Type:
Conference
Resource Relation:
Conference: 9th European Particle Accelerator Conference (EPAC 2004), Lucerne (CH), 07/05/2004--07/09/2004; Other Information: PBD: 1 Jul 2004
Research Org:
Thomas Jefferson National Accelerator Facility, Newport News, VA (US)
Sponsoring Org:
USDOE Office of Energy Research (ER) (US)
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; ACCELERATORS; BEAM CURRENTS; BEAM PROFILES; INTERFEROMETERS; INTERFEROMETRY; MONITORING; MONITORS; OPTICAL SYSTEMS; PHYSICS; RESOLUTION; SPATIAL RESOLUTION; STABILITY; SYNCHROTRONS; TRANSPORT