End Station
The final part on the beamline is the multipurpose End Station [1] equipped with angle resolved Scienta SES-200 analyzer [2]. This experiment was designed for gas phase, solid state, liquids and thin films studies. The system is divided into three parts: 1) An introduction chamber with a facility to store as many as 24 samples under vacuum conditions; 2) A transfer rod system is used to introduce the sample "holders" into the preparation chamber where the samples are attached a cryostat with a good thermal contact. The cryostat is mounted into computer controlled manipulator; 3) Using the manipulator, the samples are further transferred to a measurement position. The main analysis equipment is an SES-200 electron spectrometer from Scienta Instruments AB, Uppsala, Sweden. This and the analysis chamber are mounted on rotable, differentially pumped platforms which give full flexibility for operation.
The introduction chamber is evacuated by a turbo pump.
The preparation and analysis chambers are pumped by turbo pumps and cryopumps.
The arrangement is such that the samples are situated inside the cryopanels,
which reduces the preassure at the sample surface without excessive bakeout.
This is important when studying soft materials thin films.
In gas phase measurements very high resolution angular resolved electron spectroscopy can be performed. The radiation is very highly linearly polarized (>99%) in the horizontal plane on this beamline. The angle between analyzer and the electrical vector can be set between 0-90 deg with precision of 0.2 deg. The SES-200 analyzer resolution is appr. 15 meV using 10 eV pass energy and 0.5 mm curved slit on the analyzer.
[1] S. Svensson, J.-O. Forsell, H. Siegbahn, A. Ausmees, G. Bray, S. Södergren, S. Sundin, S. J. Osborne, S. Aksela, E. Nõmmiste, J. Jauhiainen, M. Jurvansuu, J. Karvonen, P. Barta, W. R. Salaneck, A. Evaldsson, M. Lögdlund and A. Fahlman, Rev. Sci. Instrum., 67, 2149, 1996.
[2] N. Mårtensson, P. Baltzer, P.A. Bruhwiler, J.-O. Forsell, A. Nilsson, A. Stenborg, B. Wannberg, J. Electron Spectrosc. Relat. Phenom., 70, 117, 1994.
