First operation of circular dichroism measurements with periodic photon-helicity switching by a variably polarizing undulator at BL23SU at SPring-8

Citation
A. Agui et al., First operation of circular dichroism measurements with periodic photon-helicity switching by a variably polarizing undulator at BL23SU at SPring-8, REV SCI INS, 72(8), 2001, pp. 3191-3197
Citations number
29
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Spectroscopy /Instrumentation/Analytical Sciences","Instrumentation & Measurement
Journal title
REVIEW OF SCIENTIFIC INSTRUMENTS
ISSN journal
0034-6748 → ACNP
Volume
72
Issue
8
Year of publication
2001
Pages
3191 - 3197
Database
ISI
SICI code
0034-6748(200108)72:8<3191:FOOCDM>2.0.ZU;2-C
Abstract
This article presents the first operation of the magnetic circular dichrois m (MCD) measurement system with periodic photon-helicity switching. The mea surements were performed at the newly constructed soft x-ray beamline-BL23S U- at the third-generation synchrotron radiation facility, SPring-8. The mo nochromator control system was synchronized to the movement of the magnetic row (phase shift) of an APPLE-2 (Sasaki) type variably polarizing undulato r. The periodic phase shift of the undulator provided the switching of heli city polarizing soft x rays up to 0.1 Hz. The closed-orbit distortion of th e storage ring was controlled to avoid optical axis disturbances at this be amline as well as at other beamlines. The circular dichroism spectra with h elicity switching by APPLE-2 show the possibility of high-sensitivity MCD m easurements. This method promotes precise MCD measurements and can be a pow erful technique to study magnetism as well as dichroism. (C) 2001 American Institute of Physics.