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Beamline: W3.2 (HONORMI)
Experimental Station for High Resolution Spectroscopy in the VUV
The first optical element in the beamline is a plane mirror that deflects the radiation from the miniwiggler W3 by 46° upwards. The focusing of the radiation into the entrance slit of the monochromator is performed with an elliptical torus.
The monochromator is a 3 m normal incidence instrument (McPherson 15° mounting) dispersing in the vertical plane. It is equipped with two gratings interchangeable in vacuum which allow to scan the wavelength between 35 and 300 nm. The entrance and exit slit assemblies contain three fixed slits of approximately 10, 100 and 300 µm height.
A plane mirror is reflecting the monochromatic light by 15° upwards. By means of an elliptical torus the light is deflected into the horizontal direction and focused onto a spot of about 400 x 400 µm at the sample position, which is 600 mm apart from the mirror.
The final part of the beamline is a valve with a MgF2-window, at which large UHV-compatible experimental chambers can be connected.
Monochromator drive by a stepper motor and wavelength read-out by an optical encoder can be controlled via CAMAC.
Applications
Medium and high resolution spectroscopy of atoms, molecules, fluids and solids. Some experiments include:
angular resolved photoemission (ASPHERE) of solids
photoionization of metallic clusters .
Literature
V. Saile, P. Gürtler, E.E. Koch, A. Kozevnikov, M. Skibowski, and W. Steinmann Appl. Opt. 15, (1976) 2559
T. Vaness, Ph.D. Thesis, University of Hamburg 1990, Internal Report HASYLAB 90-04
J. Meyer, A. Rieck, P. Gürtler, Einführung in den HONORMI Meßplatz (1993)
Instrument Specification
|
Source (4.5 GeV) |
wiggler, Ec = 4.2 keV at a gap of 58 mm |
|---|---|
|
Monochromator |
3 m normal incidence |
|
Wavelength range |
30 - 300 nm |
|
Resolution |
0.003, 0.03 and 0.1 nm |
|
Grating 1 |
Al/MgF coated, 1200 lines/mm blazed at 130 nm, |
|
Grating 2 |
Gold coated, 1200 lines/mm blazed at 60 n, |
|
Spot size at sample |
about 400 x 400 µm |
|
Photon flux |
1011 photons/sec at 0.1 nm resolution and 120 nm (4.5 GeV, 100mA) |
