The μmRIXS plane grating spectrometer consists of two parabolical mirrors with a plane grating in between. The first mirror collects and collimates the radiation from the 1x4 μm2 beamline microfocus on the sample onto the grating while the second mirror focusses the diffracted light onto the detector. The spectrometer houses two laminar grating structures on a common substrate: 1050 l/mm for high transmission and 4200 l/mm for high resolution. The photons are detected by a PHOTONIS multi channel pate (MCP) stack in combination with a RoentDek delay line detector DLD-120. The MCP channel diameter is 25 um and the top MCP is coated with CsI to improve the quantum efficiency of the detector.
The samples are mounted in the solid state experimental chamber directly to a Janis ST-500 Microscopy Cryostate which allows for a maximum stability for the sample position. To avoid mechanical instabilities in sample positioning, no sample translation stage is installed, but the whole vacuum chamber can be positioned by a 3-axis Huber table vertically and in the horizontal plane. Rotation of the sample around the vertical axis is achieved via a rotation of the microscope cryostate.
The μmRIXS spectrometer is permanently situated at the UE49-SGM beamline while the solid state experimental chamber can be exchanged for the coherent x-ray scattering (CXS) chamber.