A Soft X-Ray (300–1000 eV) Active Grating Monochromator Beamline at NSRRC.

Autor: Fung, H. S., Yuh, J. Y., Huang, L. J., Tseng, T. C., Perng, S. Y., Wang, D. J., Tsang, K. L., Chung, S. C.
Předmět:
Zdroj: AIP Conference Proceedings; 2007, Vol. 879 Issue 1, p563-566, 4p, 1 Diagram, 1 Chart, 4 Graphs
Abstrakt: To accommodate the growing number of users in the soft X-ray spectroscopy research at NSRRC, we have developed a modified Dragon-type beamline, namely the active grating monochromator (AGM) beamline. In this beamline, a selected photon beam of 9 mrad radiation fan in the horizontal direction from a bending magnet is focused horizontally by a tangential elliptical mirror to a position 1.7 m after exit slit, and vertically by a cylindrical vertical focusing mirror (VFM) onto the entrance slit. After the entrance slit, the photon beam is energy-dispersed and vertically focused by an active grating onto the fixed exit slit. During the energy scan, the radius and shape of the active grating are adjusted accordingly, and therefore the defocus and coma aberrations terms can be effectively eliminated, and hence the energy resolution is optimized. Following the exit slit, the dispersed photon beam is refocused by a toroidal mirror onto the sample. Shadow ray-tracing program is employed to simulate the beamline performance. Results show that the energy resolution can reach 10000, 6000, and 3500 in the energy ranges of 300–400 eV, 400–600 eV, and above 600 eV, respectively. The total photon flux at sample position should reach 1×1012 phs/sec/200mA/0.1%BW, and the focused beam size at sample position is estimated to be 1 mm × 0.2 mm (H × V, FWHM). This beamline is currently under construction and will be ready for commission in December, 2006. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]
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