Novel low-temperature detectors for spectroscopy, apart from their excellent resolution which is comparable to that of crystal spectrometers, have the advantage of covering a broad range of energies, opening up new opportunities for high-precision X-ray spectroscopy. In the framework of the SPARC collaboration at Heidelberg university, the maXs calorimeter is being developed (Cryogenic Micro-Calorimeter Arrays for High Resolution X-ray Spectroscopy at FAIR), specially tailored to X-ray spectroscopy at the future accelerator facility FAIR. The two-dimensional array will cover an energy range between a few keV and about 200 keV, delivering a resolution of better than 3 eV for photons up to 20 keV, and 50 eV for hard X-ray radiation.

Initial test experiments of the calorimeter, in combination with X-ray optical components manufactured at Jena university, are scheduled to commence soon at Helmholtz Institute Jena.