Elliptically polarised soft x-rays produced using a local bump in MAX II - Characterisation of the degree of polarisation
- MAX-lab, Lund University, SE-221 00, Lund (Sweden)
- Department of Physics, Uppsala University, Box 530, SE-751 21 Uppsala (Sweden)
MAX-lab has introduced a local perturbation to the electron orbit of the MAX II storage ring, providing users at the SX700 monochromator beam line, D1011, with elliptically polarised soft x-rays. This is achieved by using corrector magnets to send the electron orbit on an ascending or descending trajectory through the dipole magnet source. This simple 'bump' approach has many advantages over and above insertion device based solutions. To illustrate the potential of the approach, the degree of circular polarisation, Pc, has both been calculated and measured. The calculation was made by applying the Stokes formalism to the intensities given by the standard dipole emission formula. Experimentally Pc was characterised using x-ray magnetic circular dichroism measurements. In such experiments magnetic contrast scales directly proportional to Pc. Using a 25 atomic layer bcc Fe film deposited on the Cu(100) surface as a calibration standard the spin moment, ms, was determined. By comparing the values of ms obtained here with those reported earlier, the degree of circular polarisation could be estimated. At {approx} 715 eV the calculated and measured values of Pc are 0.93 and 0.85, respectively.
- OSTI ID:
- 20653035
- Journal Information:
- AIP Conference Proceedings, Vol. 705, Issue 1; Conference: 8. international conference on synchrotron radiation instrumentation, San Francisco, CA (United States), 25-29 Aug 2003; Other Information: DOI: 10.1063/1.1757735; (c) 2004 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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