Compton scattering off polarized electrons with a high-finesse Fabry-PerotCavity at JLab

Citation
N. Falletto et al., Compton scattering off polarized electrons with a high-finesse Fabry-PerotCavity at JLab, NUCL INST A, 459(3), 2001, pp. 412-425
Citations number
13
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Spectroscopy /Instrumentation/Analytical Sciences","Instrumentation & Measurement
Journal title
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT
ISSN journal
0168-9002 → ACNP
Volume
459
Issue
3
Year of publication
2001
Pages
412 - 425
Database
ISI
SICI code
0168-9002(20010301)459:3<412:CSOPEW>2.0.ZU;2-2
Abstract
We built and commissioned a new type of Compton polarimeter to measure the electron beam polarization at the Thomas Jefferson National Accelerator Fac ility (Virginia, USA). The heart of this polarimeter is a high-finesse mono lithic Fabry-Perot cavity. Its purpose is to amplify a primary 300 mW laser beam in order to improve the signal to noise ratio of the polarimeter. It is the first time that a high-finesse Fabry-Perot cavity is enclosed in the vacuum of a particle accelerator to monitor the beam polarization by Compt on polarimetry. The measured finesse and amplification gain of the cavity a re F = 26 000 and G = 7300. The electron beam crosses this high-power photo n source at an angle of 23 mrad in the middle of the cavity where the photo n beam power density is estimated to be 0.85 MW/cm(2). We have used this fa cility during the HAPPEX experiment (April-July 1999) and we give a prelimi nary measurement of Compton scattering asymmetry. (C) 2001 Elsevier Science B.V. All rights reserved.