EURECA: European-Japanese Microcalorimeter Array

Abstract

The EURECA (EURopean-JapanEse Calorimeter Array) project aims to demonstrate the science performance and technological readiness of an imaging X-ray spectrometer based on a micro-calorimeter array for application in future X-ray astronomy missions, like Constellation-X and XEUS. The prototype instrument consists of a 5 x 5 pixel array of TES-based micro-calorimeters read out by by two SQUID-amplifier channels using frequency-domain-multiplexing (FDM). The SQUID-amplifiers are linearized by digital base-band feedback. The detector array is cooled in a cryogenfree cryostat consisting of a pulse tube cooler and a two stage ADR. A European-Japanese consortium designs, fabricates, and tests this prototype instrument. This paper describes the instrument concept, and shows the design and status of the various sub-units, like the TES detector array, LC-filters, SQUID-amplifiers, AC-bias sources, digital electronics, etc. Initial tests of the system at the PTB beam line of the BESSY synchrotron showed stable performance and an X-ray energy resolution of 1.58 eV at 250 eV and 2.5 eV @ 5.9 keV for the read-out of one TES-pixel only. Next step is deployment of FDM to read-out the full array. Full performance demonstration is expected mid 2009.

Performance of an X-ray single pixel TES microcalorimeter under DC and AC biasing

“…We are developing an imaging array of Transition Edge Sensor (TES) microcalorimeters and bolometers for future X-ray and Infrared astronomy mission like IXO (International X-ray Observatory) and SPICA. The experiment described here is part of the European-Japanese project EURECA, which aims to demonstrate technological readiness of a 5 x 5 pixel array of TES-based microcalorimeters read-out by two SQUID-amplifier channels using frequency-domain-multiplexing (FDM) [5]. FDM requires amplitude modulation (AM) of the TES signal and it can be achieved by biasing the TES with an AC voltage bias source in a LC resonant circuit.…”