Home
Beamline: F2.2 (SEYA)
Angle-Resolved Photoelectron Spectroscopy
The first optical element in the beamline is a cylindrical mirror (S1) focusing sagitally 6 mrad of bending magnet radiation into the entrance slit of the monochromator. This is followed by a plane elliptical mirror (S2) which focuses tangentially into the entrance slit of the monochromator. The monochromator is a one meter Seya-Namioka instrument dispersing in the vertical plane. It is equipped with two gratings interchangeable in vacuum which allow the wavelength range to be scanned between 30 and 250 nm. The slit width of the entrance and exit slits are continuously adjustable from 10 µm to 1 mm. The monochromatic light is refocused by means of a toroidal mirror (S3) in a spot of less than 4x1 mm2 at the sample position.
The experimental chamber is UHV compatible and equipped with an angle resolving electron spectrometer (VG ADS 400). Further equipment includes a sample manipulator, sample transfer stage and a sample preparation chamber. The latter is equipped with standard UHV-surface science equipment such as a evaporation unit, quartz oscillator, LEED system, ion gun, gas handling system and a He-lamp.
The photoelectron spectrometer and data aquisition system are controlled by a PDP 11/23 computer via CAMAC.
Applications
Angle resolved photoelectron spectroscopy from oriented fullerene films, semiconductors and from adsorbates on single crystals.
Literature on Instrumentation
C.A. Feldmann, R. Engelhardt, T. Permien, E. E. Koch, and V. Saile, Nucl. Instr. Meth. 208 (1983) 785
R. Engelhardt, Diplomarbeit Univ. Hamburg 1981, Int. Bericht HASYLAB 81-13
H.H. Rüter, Diplomarbeit Univ. Hamburg 1987, Int. Bericht HASYLAB 87-08
Instrument Specification
|
Source (4.5 GeV) |
bending magnet, Ec = 16.6 keV |
|---|---|
|
Monochromator |
one meter Seya-Namioka |
|
Grating 1 |
Al/MgF coated, 600 lines/mm blazed at 160 nm, 65 nm << 250 nm |
|
Typical resolution |
with 25 µm slits about 0.09 nm |
|
Grating 2 |
Platinum coated, 1200 lines/mm blazed at 80 nm, 30 nm << 80 nm |
|
Typical resolution |
with 25 µm slits about 0.05 nm |
|
Spot size at sample |
about 4 x 1 mm2 |
|
Flux at the sample |
1011 photons/sec at 0.1 nm resolution |
|
Analyser |
angle resolved electron spectrometer (VG ADES 400) |
|
Angle resolution |
about 2° |
|
Energy resolution |
0.04 eV < E < 4 eV |
