Search

Accepted: 2012-02-22, 資料番号: SA1003109000

The EURECA project aims to demonstrate technological readiness of a micro-calorimeter array for application in future X-ray astronomy missions, like Constellation-X, EDGE, and XEUS. The prototype instrument consists of a 5 × 5 pixel array of TES-based micro-calorimeters read out by two SQUID-amplifier channels using frequency-domain-multiplexing (FDM) with digital base-band feedback. The detector array is cooled by a cryogen-free cryostat consisting of a pulse tube cooler and a two stage ADR. Initial tests of the system at the PTB beam line of the BESSY synchrotron showed stable performance and an X-ray energy resolution of 1.5 eV at 250 eV for read-out of one TES-pixel only. Next step is deployment of FDM to read-out the full array. Full performance demonstration is expected end 2008., This work was financially supported by the Dutch Organization for Scientific Research (NWO).

The TES cryogenic detectors, due to their high spectral resolution and imaging capability in the soft X-ray domain, are the reference devices for the next proposed space missions whose aims are to characterize the spectra of faint or diffuse sources. ATHENA is the re-scoped IXO mission, and one of its focal plane instrument is the X-ray Microcalorimeter Spectrometer (XMS) working in the energy range 0.3-10 keV. XMS will be able to achieve the proposed scientific goals if a background lower than 0.02 cts/cm2/s/keV is guaranteed. The studies performed by GEANT4 simulations depict a scenario where it is mandatory to use an active Anti-Coincidence (AC) to reduce the expected background in the L2 orbit down to the required level. This is possible using a cryogenic AC detector able to provide a rejection efficiency of about 99%. We are developing for this purpose a TES-based detector made by Silicon absorbers (total assembled area about 1 cm2 and 300 ?m thick) and sensed by a Ir:Au TES. All the work done for IXO is applicable to ATHENA, with more margins due to the smaller area required for the detector. Here we present the results obtained from different samples, as a step towards the final detector design.

ATHENA+ is a space mission proposal for the next ESA L2-L3 slot. One of the focal plane instruments is the X-ray integral field unit (X-IFU) working in the energy range 0.3–10 keV. It is a multi-array based on TES detectors aimed at characterizing faint or diffuse sources (e.g. WHIM or galaxy outskirt). The X-IFU will be able to achieve the required sensitivity if a low background is guaranteed. The studies performed by GEANT4 simulations depict a scenario where the use of an active anticoincidence (AC) is mandatory to reduce the background expected in L2 orbit down to the goal level of 0.005 cts cm $$^{-2}$$ s $$^{-1}$$ keV $$^{-1}$$ . This is possible using a cryogenic anticoincidence (CryoAC) detector placed within a proper optimized environment surrounding the X-IFU. We propose a 2 $$\times $$ 2 array of microcalorimeter detectors made by silicon absorber (each of about 1 cm $$^{2}$$ and 300 $$\upmu $$ m thick) and sensed by an Ir TES. In order to better understand the involved physics and optimize the performance, we have produced several samples featured by different absorber areas, TES size, and QPs Al collectors. Here we will discuss, as a review, the obtained results and the related impact to the final detector design.

“The Hot and Energetic Universe” is the scientific theme approved by the ESA SPC for a Large mission to be flown in the next ESA slot (2028th) timeframe. ATHENA is a space mission proposal tailored on this scientific theme. It will be the first X-ray mission able to perform the so-called “Integral field spectroscopy”, by coupling a high-resolution spectrometer, the X-ray Integral Field Unit (X-IFU), to a high performance optics so providing detailed images of its field of view (5’ in diameter) with an angular resolution of 5” and fine energy-spectra (2.5eV@E

ATHENA has been the re-scoped IXO mission, and one of the foreseen focal plane instrument was the X-ray Microcalorimeter Spectrometer (XMS) working in the energy range 0.3-10 keV, which was a kilo-pixel array based on TES (Transition Edge Sensor) detectors. The need of an anticoincidence (AC) detector is legitimated by the results performed with GEANT4 simulations about the impact of the non x-ray background onto XMS at L2 orbit (REQ. < 0.02 cts/cm2/s/keV). Our consortium has both developed and tested several samples, with increasing area, in order to match the large area of the XMS (64 mm2). Here we show the preliminary results from the last prototype. The results achieved in this work offer a solution to reduce the particle background not only for the presently study mission, but also for any satellite/balloon borne instrument that foresees a TES-based microcalorimeters/bolometers focal plane (from millimeter to x-ray domain). © 2012 SPIE.

The technique which combines high resolution spectroscopy with imaging capability is a powerful tool to extract fundamental information in X-ray Astrophysics and Cosmology. TES (Transition Edge Sensors)-based microcalorimeters match at best the requirements for doing fine spectroscopy and imaging of both bright (high count rate) and faint (poor signal-to-noise ratio) sources. For this reason they are considered among the most promising detectors for the next high energy space missions and are being developed for use on the focal plane of the IXO (International X-ray Observatory) mission. In order to achieve the required signal-to-noise ratio for faint or diffuse sources it is necessary to reduce the particle-induced background by almost two orders of magnitude. This reduction can only be achieved by adopting an active anticoincidence technique. In this paper, we will present a novel anticoincidence detector based on a TES sensor developed for the IXO mission. The pulse duration and the large area of the IXO TESarray (XMS X-ray Microcalorimeter Spectrometer) require a proper design of the anticoincidence detector. It has to cover the full XMS area, yet delivering a fast response. We have therefore chosen to develop it in a four-pixel design. Experimental results from the large-area pixel prototypes will be discussed, also including design considerations.