High-Resistivity Transition-Edge Sensor Modeling and Expected Performances

International audienceHigh spectral resolution detectors based on low-resistivity transition-edge sensors (TES) are being developed for future X-ray spatial observatories, but difficulties (cryogenics limitations) are to be expected in next generation’s detectors with even more pixels. A new technology, the high-resistivity TES (HRTES), is likely to offer similar performance to existing TES when associated to an active electrothermal feedback, adding the possibility of moving the readout electronics to a 2.5 K stage of the cryocooler. This work aims to investigate HRTES by making a precise model of the device, comparing it to experimental measurements, and deducing its performance potential

High impedance TES with classical readout electronics: a new scheme toward large x-ray matrices

International audienceHigh impedance transition edge sensors (TES) are good candidates to constitute the sensitive part of new X-ray spectroimagers for the spatial X-ray observation, with even greater number of pixels. We test this solution in this context, developing an original scheme of readout that consist in implementing an active electro-thermal feedback, performed by a low noise cryogenic electronics, in order to solve the problematic effects of the electron-phonon decoupling, to ensure the stability of the system, and to increase the dynamic range of the detector. This paper presents the status of our developments, including the characterisation of the sensor, the experimental test of the active electro-thermal feedback, and our very first results of photon detection.© (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

Limits in point to point resolution of MOS based pixels detector arrays

International audienceIn high energy physics point-to-point resolution is a key prerequisite for particle detector pixel arrays. Current and future experiments require the development of inner-detectors able to resolve the tracks of particles down to the micron range. Present-day technologies, although not fully implemented in actual detectors, can reach a 5-μm limit, this limit being based on statistical measurements, with a pixel-pitch in the 10 μm range. This paper is devoted to the evaluation of the building blocks for use in pixel arrays enabling accurate tracking of charged particles. Basing us on simulations we will make here a quantitative evaluation of the physical and technological limits in pixel size. Attempts to design small pixels based on SOI technology will be briefly recalled here. A design based on CMOS compatible technologies that allow a reduction of the pixel size below the micrometer is introduced here. Its physical principle relies on a buried carrier-localizing collecting gate. The fabrication process needed by this pixel design can be based on existing process steps used in silicon microelectronics. The pixel characteristics will be discussed as well as the design of pixel arrays. The existing bottlenecks and how to overcome them will be discussed in the light of recent ion implantation and material characterization experiments

La France dans le regard des États-Unis

Les études consacrées aux représentations européennes des États-Unis sont nombreuses : elles concernent bien des disciplines et se partagent le plus souvent entre l’analyse d’une fascination et celle d’une répulsion. En revanche les travaux qui traitent du regard que les États-Unis portent sur l’Europe et sur les pays qui la constituent sont plus rares ou, en tout cas plus ponctuels, et ils n’ont pas donné lieu à une herméneutique élargie. C’est, par suite, dans ce champ relativement peu défriché que s’est placé le colloque international qui s’est tenu les 5-6-7 et 8 octobre 2005 aux universités de Montpellier et de Perpignan ; il s’est concentré sur la France, de tous les pays européens, celui dont, dit-on, l’antiaméricanisme est le plus farouche, mais aussi, peut-être, où la fascination pour les États-Unis est la plus forte et, dans une large perspective interdisciplinaire se sont réunis historiens, sociologues, politistes, philosophes, anthropologues, économistes américains et français mais aussi d’autres nationalités. Ce sont les textes issus des communications entendues durant ces quatre journées que l’on trouvera regroupés dans ce livre