The beamline is sourced by an elliptically polarizing undulator (EPU). There is no entrance slit in this design. A toroidal mirror M1 collects the diverging beam from the undulator and collimates it vertically (in the dispersive plane of the grating G). M1 also focuses the beam horizontally at the exit slit ES. The monochromator is a combined collimated cNIM and cPGM type. The monochromator energy disperses the radiation, which is then focused vertically at the exit slit by a cylindrical mirror M3. The horizontal image of the source at the exit slit is refocused at the sample position by an ellisoidal mirror M4 with a demagnification of 10:1.

The exit slit unit also consists of a combination of gas filters and solid state thin film filters for the suppression of higher order light.

The Monochromator and the exit slits are delivered by TOYAMA, Japan and the mirror chambers by FMB, Berlin.

Infrastructure around the beam line will among other things consist of Data taking hutch for users, basic preparation lab, storage hutch,  beamline staff hutch with meeting room for beamline staff and users, radiation protection hutch,  water cooled cabinets for beamline and experimental station control units, venting nitrogen, pressurized air, internet connections, power outlets and 1 ton crane.

Overview of beam line parameters:

Undulator: Apple type elliptically polarising undulator with 84 mm period length.

Energy range: 10 – 1000 eV

Gratings: Place for 4 gratings. Initially 3 grating will be installed. 4000 lines/mm for cNIM mode and 800 and 2400 lines/mm for the cPGM mode.

Energy resolution:  about 100 000 for energies less than 100 eV and  about 10 000 up to 1000 eV

Flux: 10e13 to 7e9 in the range of 10-1000 eV using 800 lines/mm grating with a resolving power of 10e4 and about 10e11 for 2400 lines/mm grating with resolving power of 10e5 for energies up to 100eV.

Spot size at the sample position: Nominal size of 10μm x 40μm (VxH) for  100μm exit.

 

ARPES_flux_curves
Calculated flux with 10000 resolving power for 800l/mm with spot size 40μmx10μm (red) and 25μmx10μm (green), 1meV resolution up to 100eV for 2400l/mm (green), and 4000l/mm in NIM-mode using a 25μm exit slit.