Alternative Readout Electronics for Superconducting Transition Edge Sensors

A simple idea of using transformers as impedance adapters between TES and conventional JFET amplifiers, allowing to built an electronic readout system that does not degenerate the signal, will be presented. The theoretical modelling and systematic experimental results of such devices, indicate that there is a frequency range were the amplifier noise is negligible with respect to the TES noise

The cryogenic anticoincidence detector for ATHENA-XMS: Preliminary results from the new prototype

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). \uc2\ua9 2012 SPIE

The Cryogenic AntiCoincidence detector for ATHENA: The progress towards the final pixel 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<7keV). The X-IFU is a kilo-pixel array based on TES (Transition Edge Sensor) microcalorimeters providing high resolution spectroscopy in the 0.2-12 keV range. Some goals is the detection of faint and diffuse sources as Warm Hot Intergalactic Medium (WHIM) or galaxies outskirts. To reach its challenging scientific aims, it is necessary to shield efficiently the X-IFU instrument against background induced by external particles: the goal is 0.005 cts/cm2/s/keV. This scientific requirement can be met by using an active Cryogenic AntiCoincidence (CryoAC) detector placed very close to X-IFU (\ue2\u88\ubc 1 mm below). This is shown by our GEANT4 simulation of the expected background at L2 orbit. The CryoAC is a TES based detector as the X-IFU sharing with it thermal and mechanical interfaces, so increasing the Technology Readiness Level (TRL) of the payload. It is a 2x2 array of microcalorimeter detectors made by Silicon absorber (each of about 80 mm2 and 300 \uce\ubcm thick) and sensed by an Ir TES. This choice shows that it is possible to operate such a detector in the so-called athermal regime which gives a response faster than the X-IFU (< 30 \uce\ubcs), and low energy threshold (above few keV). Our consortium has developed and tested several samples, some of these also featured by the presence of Al-fins to efficiently collect the athermal phonons, and increased x-ray absorber area (up to 1 cm2). Here the results of deep test related to one of the last sample produced (namely AC-S5), and steps to reach the final detector design will be discussed

The TES-based cryogenic anticoincidence detector for IXO: First results from large area prototypes

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 TES-array (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. \ua9 2010 SPIE

An Innovative Approach for Subnational Climate Adaptation of Biodiversity and Ecosystems: The Case Study of a Regional Strategy in Italy

Since climate change impacts are already occurring, urgent adaptive actions are necessary to avoid the worst damages. Regional authorities play an important role in adaptation, but they have few binding guidelines to carry out strategies and plans. Sectoral impacts and adaptive measures strongly differ between regions; therefore, specific results for each territory are needed. Impacts are often not exhaustively reported by literature, dataset and models, thus making it impossible to objectively identify specific adaptive measures. Usual expert elicitation helps to fill this gap but shows some issues. For the Piedmont Strategy, an innovative approach has been proposed, involving experts of private and public bodies (regional authorities, academia, research institutes, parks, associations, NGOs, etc.). They collaborated in two work group, first to identify current and future impacts on biodiversity and ecosystems, and secondly to elaborate and prioritize measures. Involving 143 experts of 46 affiliations, it was possible to quickly edit a cross-validated list of impacts (110) and measures (92) with limited costs. Lastly, a public return of results took place. This approach proved to be effective, efficient and influenced the policymakers, overcoming the tendency to enact long-term actions to face climate change. It could be used internationally by subnational authorities also in other sectors

The Status of the MARE Experiment with 187Re and 163Ho Isotopes

Neutrino oscillation experiments have proved that neutrinos are massive particles but the assessment of their absolute mass scale is still an outstanding challenge in today particle physics and cosmology. The laboratory experiments dedicated to effective electron-neutrino mass determination are the ones based on the study of single beta decay or electron capture (EC) decay. Exploiting only on energy-momentum conservation, this kinematic measurement is the only one which permits to estimate neutrino masses without theoretical assumptions on neutrino nature and it is truly modelindependent. To date the most competitive isotopes for a calorimetric measurement of the neutrino mass are 187Re and 163Ho. While the first decays beta, the latter decays via electron capture, and both have a Q-value around 2.5 keV. The measurement of 163Ho EC is an appealing alternative to the 187Re beta decay measurement because few nuclei are needed and it is a self-calibrating measurement. In this context the MARE project, based on rhenium thermal detectors has been born. We report here the status of MARE in Milan with Rhenium and the activity concerning the production of radioactive 163Ho isotope in the framework of MARE

SAGACE:The spectroscopic active galaxies and clusters explorer

The SAGACE experiment consists of a mm/sub-mm telescope with a 3-m diameter primary mirror, coupled to a cryogenic multi-beam differential spectrometer. SAGACE explores the sky in the 100-760 GHz frequency range, using four diffraction-limited bolometer arrays. The instrument is designed to perform spectroscopic surveys of the Sunyaev- Zeldovich effects of thousands of galaxy clusters, of the spectral energy distribution of active galactic nuclei, and of the [CII] line of a thousand galaxies in the redshift desert. In 2008 a full phase-A study for a national small mission was completed and delivered to the Italian Space Agency (ASI). We have shown that taking advantage of the differential operation of the Fourier Transform Spectrometer, this ambitious instrument can operate from a Molniya orbit, and can be built and operated within the tight budget of a small mission.</p