Department Spin and Topology in Quantum Materials

PGM2 Beamline

The beamline is purpose-built to provide high flux and resolution in the energy range from 5−200 eV. The light source is an APPLE2 undulator (UE112) that allows for full control over the polarization. Its light is further refined by a collimated low-energy plane grating monochromator that can be operated with either a 600 or 2400 l/mm grating. A normal incidence option with a 2400 l/mm grating is available to retain intensity and polarization at the lowest energies. The monochromated light can be directed to either the right exit arm towards the 1³ station, or the left branch towards 1². Resolving powers in excess of 100.000 have been demonstrated with the 2400 l mm⁻¹ grating. However, the 600 l mm⁻¹ grating provides ample resolution (> 20.000) and superior flux (10¹²−10¹³ photons s⁻¹ 0.1 A⁻¹), which means it is used for most experiments.

PGM2

Spot-sizes of 210 and 465 µm have been achieved on the right (1³) and left (1²) branch, respectively. An upgrade to improve the focus on the latter branch is planned in the nearest future.

Further reading

•  R. Follath, J. S. Schmidt, A grazing incidence monochromator for the photon energy range 5-250 eV, Proceedings of the Eighth International Conference on Synchrotron Radiation Instrumentation.

•  R. Follath, The versatility of collimated plane grating monochromators, Nuclear Instruments and Methods in Physics Research A 467–468 (2001) 418–425.