Source Type
Bending magnet
Optical System
Monochromator: Modified Wadsworth normal incidence monochromator located 2.7 meters from the source.
Mirror: Spherical concave quartz blank iridium coated mirror; mirror is water cooled and fixed position; 200 mm by 50 mm with 2.8 meter radius; dumps hard x-ray radiation and provides parallel rays to grating; 6 degree angle of incidence; high energy cutoff is 35 eV (350 Angstroms) depending on grating used.
Grating: Spherical concave 4 meter radius focusing grating, vertical focal point at exit slit 2 meters beyond monochromator, horizontal focal point and interaction point 27 mm beyond exit slit; has same dimensions as mirror; 1200 grooves/mm grating is a quartz blank osmium coated ion etched laminar grating, highest efficiency below 11 eV (1100 Angstroms).
Experimental Apparatus
VUV CD Apparatus: an UHV chamber which can be outfitted to perform CD or fluorescence measurements. The Circular Dichroism Spectrometer consists of a Calcium Floride Photoelastic Modulator, a thermostated V-Block sample holder (temperature control from –5 degrees C up to 70 degrees C), and an end on Quartz Photomultiplier Detector. The instrument can perfom standard or time-resolved fluorescence. A conventional magnet is available for Magnetic Circular Dichroism experiments also. Since the sample chamber vacuum can be separated from the beamline via either of two isolation windows, the sample chamber can be purged with dry nitrogen or evacuated to 10-5 Torr.
Computer System Hardware & Software
Intel processor MS-Windows operating system running custom software for beamline control, data acquisition and storage.