Calculated Performance Of The Variable-Polarization Undulator Upgrade To The Daresbury SRS Soft X-Ray Undulator Beamline

• Published in: AIP conference proceedings Vol. 705; no. 1; pp. 444 - 447
• Main Authors: Roper, Mark D, Bird, Daniel T
• Format: Journal Article
• Language: English
• Published: United States 12.05.2004
• Subjects: BEAM OPTICS; CARBON; DESIGN; ELECTRONS; EV RANGE 100-1000; HARMONICS; NITROGEN; OXYGEN; PARTICLE ACCELERATORS; POLARIZATION; SOFT X RADIATION; STORAGE RINGS; SYNCHROTRON RADIATION; WIGGLER MAGNETS
• ISBN: 0735401802; 9780735401808
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/1.1757829

The soft x-ray beamline 5U1 on the Daresbury Laboratory SRS currently uses a planar undulator, producing linearly polarized radiation in the range 100 to 1000 eV. The undulator is soon to be replaced by a variable-polarization device of the Apple II design. The aim is to produce circularly polarized light in the energy range 265 to 1000 eV, covering the K-edges of C, N & O, and the first row transition element L-edges. This will greatly enhance the provision of circularly polarized soft-x-rays on the SRS and open up new opportunities for experimenters. The device will also produce linear polarization with a selectable angle of polarization with respect to the orbit plane, which is currently unavailable on the SRS. In order to provide the coverage over this energy range, we are exploiting the relatively large emittance of the SRS to allow us to use the second and third harmonics even in circular polarization mode. This paper presents the expected beamline output in various polarization modes and the predicted degree of polarization.