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Title: Polarization measurement and vertical aperture optimization for obtaining circularly polarized bend-magnet radiation

Journal Article · · Review of Scientific Instruments
DOI:https://doi.org/10.1063/1.1147471· OSTI ID:390556
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  1. Center for X-Ray Optics, Advanced Light Source, Chemical Sciences Division, Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

Using multilayer linear polarizers, we have characterized the polarization state of radiation from bend-magnet beamline 9.3.2 at the Advanced Light Source as a function of vertical opening angle at photon energies of 367 and 722 eV. Both a fine slit and a coarse semi-aperture were stepped across the beam to accept different portions of the vertical radiation fan. Polarimetry yields the degree of linear polarization directly and the degree of circular polarization indirectly assuming an immeasurably small amount of unpolarized radiation based on the close agreement of the theoretical and experimental results for linear polarization. The results are in good agreement with theoretical calculations, with departures from theory resulting from uncertainty in the effective aperture of the measured beam. The narrow 0.037-mrad aperture on the orbit plane transmits a beam whose degree of linear polarization exceeds 0.99 at these energies. The wide semi-aperture blocking the beam from above and below transmits a beam with a maximum figure of merit, given by the square root of flux times the degree of circular polarization, when the aperture edge is on the orbit plane thus blocking only half of the total available flux. {copyright} {ital 1996 American Institute of Physics.}

Research Organization:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
DOE Contract Number:
AC03-76SF00098
OSTI ID:
390556
Report Number(s):
CONF-9510119-; ISSN 0034-6748; TRN: 96:027981
Journal Information:
Review of Scientific Instruments, Vol. 67, Issue 9; Conference: SRI `95: synchrotron radiation instrumentation symposium and the 7. users meeting for the advanced photon source (APS), Argonne, IL (United States), 16-20 Oct 1995; Other Information: PBD: Sep 1996
Country of Publication:
United States
Language:
English