Flux-ramp SQUID-multiplexing for kilo-pixel microcalorimeter-arrays

Within this project a world-unique, novel, and efficient multiplex method will be developed which will bundle within one read-out channel the signals from 8 to 32 micro calorimeters for high-resolution x-ray spectrometry. This project builds on the developments of the forgoing project, where micro-calorimeter arrys of the type maXs were adapted to the experimental environment at FAIR. These detectors are world-leading in resolving power. In addition, they exhibit an excellent linearity and a fast intrinsic signal rise-time. The new multiplexing method will enable the enlargement of the micrco-calorimeter arrays by up to two orders of magnitude such that the active area will be as large as for standard germanium detectors, but, at at up to a hundred times better energy resolution. This world-unique combinaton of band pass, energy resolving-power, and active area  will allow for a much more efficient use of beam times at storage rings and modern light sources. In particular, this development is essential for the envisaged experiments on precision spectroscopy at the CRYRING electron cooler.