| SRON's research and development on detectors for X-ray astrophysics focuses on cryogenic imaging spectrometers and their read-out. These activities are driven by ESA's XEUS mission, but other astronomical applications are actively pursued as well. In the spectrometer arrays, each pixel uses a superconducting-to-normal phase transition thermometer, generally called TES, operating at 100 mK. Frequency Domain Multiplexing (FDM) based on SQUID current amplifiers is developed for the read-out of the detector arrays. The research at SRON has resulted in TES-micro calorimeters with the world's best energy resolution, state of the art 5 x 5 pixel arrays, and proof of principle for FDM. Additional funding from NWO-EW and ESA-TRP for this work has been acquired. SRON has two dilution refrigerators available for this research. They are mostly adequate, but do pose some serious limitations. SRON applies for funding to purchase a compact, transportable, adiabatic demagnetization refrigerator with a radiation entrance window, costing 108.033 Euro. The radiation window allows, for the first time, TES-microcalorimeter characterization at arbitrary X-ray energies and count rates at the BESSY synchrotron, rather than the single line from an X-ray source inside the dilution refrigerator. The radiation window also allows for detector characterization at sub-mm wavelengths for TES-based bolometers and new research on kinetic inductance detectors for sub-mm astronomy. |
