U41_PGM is a microfocus beamline with flexible end stations. It provides high photon flux and small focus size in soft x-ray range.
U41 undulator delivers the highest brilliance photon beam (with horizontal linear polarization) among Bessy's undulators. It has 77 magnet units with period length 41.2 mm. The smallest undulator gap is 15.5 mm.
|Energy range||170 - 1800 eV|
|Energy resolution||> 2000|
|Divergence horizontal||1.2 mrad|
|Divergence vertical||0.5 - 2.5 mrad|
|Focus size (hor. x vert.)||23 μm (hor.) x 12 μm (ver.), (FWHM, exit slit 40 μm)|
|Distance Focus/last valve||475 mm|
|Height Focus/floor level||1376 mm|
|Free photon beam available||yes|
|Fixed end station||no|
|premonochromator optics||M1: toroidal mirror, horizontal deflection, 2Θ=176°, gold coated, water cooled, vertical collimation, horizontal focusing onto exit slit|
plane grating monochromator with collimated light, operated at negative diffraction order (cff < 1)
G1: plane gratings, 600 l/mm, blaze 0.8°, vertical deflection, 2Θ=169-175°, gold coated, water cooled
M2: plane mirror, vertical deflection, 2Θ=169-175°, gold coated, water cooled
|focusing mirror||M3: cylindrical mirror, horizontal deflection, 2Θ=176°, gold coated, vertical focusing onto exit slit|
|exit slit||slit settings: 20/40/100/200/500/2000/3000 μm|
± 200 mm translation
|postmonochromator optics||M4: toroidal mirror, horizontal deflection, 2Θ=176°, gold coated, vertical and horizontal demagnification of exit slit into sample area|
|references|| R. Follath, F. Senf, Nucl. Instr. Meth. vol. A390 (1997) 388-394.|
 M.R. Weiß, R. Follath, F. Senf, W. Gudat, J. Electr. Spectrosc. Relat. Phenom. vol. 101-103 (1999) 1003-1012.
 Ch. Jung et al., Proceedings SRI 2000.
Useful information for users connecting end station to beamline:
The last valve at the end of the beamline is a window valve with DN 63 CF flange. A bellow is required for connection of end station to beamline in order to relieve any possible stress on refocusing chamber imposed by end station. The window valve can only be open when the pressure at the end station side is in 10-9 mbar range (interlock protected, bypassing the interlock is prohibited). Oil pump is not allowed when connected to beamline.
Beamline provides 220V and 380V electrical power for users. Cooling water (30°/40°, 10 bar/2 bar), pressurized air (8 bar), oil free exhausting lines, helium recycle system and internet connection (cable and wireless) are also available for users.
For further information, please contact beamline scientist.