Fabrication of ultra-low radioactivity detector holders for Edelweiss-II Navick, X.-F.; Carty, M.; Chapellier, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
03/2004, Letnik:
520, Številka:
1-3
Journal Article
Recenzirano
In its first stage, the EDELWEISS-II dark matter experiment will use 21×320g ionization-heat bolometers with NTD thermal sensors. To improve the present sensitivity of EDELWEISS to WIMP interactions ...by a further factor 100, ultra-low radioactivity detector holders exclusively made of copper and Teflon have been designed. The new design is using the relative expansion coefficients of copper, Teflon and germanium to hopefully ensure a dissipation-free detector holding.
In order to validate this new holder, we need to compare the vibration behavior of the old holder and the new one. The amplitude of the bolometer vibrations is measured using the variation of capacitance between electrodes sputtered on the Ge crystal and reference electrodes fixed above the detector holders. We present noise measurements and compare them to the equivalent measurements using the detector holders of the Edelweiss-I experiment, which gave very satisfying results.
EURECA (European Underground Rare Event Calorimeter Array) is a new project, searching for dark matter, with largely the present groups of the CRESST and EDELWEISS experiments and already a few new ...groups. The aim is to explore scalar cross sections in the 10−9 - 10−10 pico-barn region with a target mass of up to one tonne. A major advantage of EURECA is our planned use of more that just one target material (multi target experiment for WIMP identification). In preparation for this large-scale experiment, R&D for EURECA is provided through the current phases of CRESST and EDELWEISS.
Several aspects of the analysis of the data obtained with the cryogenic heat-and-ionization Ge detectors used by the EDELWEISS dark matter search experiment are presented. Their calibration, the ...determination of their energy threshold, fiducial volume and nuclear recoil acceptance are detailed.
X-ray Astronomy provides a unique window on a wide variety of astrophysical phenomena. The currently operating X-ray space observatories perform X-ray spectral imaging with the use of CCDs. When ...available, cryogenic X-ray microcalorimeter arrays will far outperform CCDs in terms of spectral resolution, energy bandwidth and count rate. Experience has been gained with Infra-Red bolometer arrays at CEA-LETI (Grenoble) in collaboration with the CEA-SAp (Saclay); taking advantage of this background, we are now developing an X-ray spectro-imaging camera for the next generation space astronomy missions, using silicon technology (implanted and high temperature diffused thermistors).
Each pixel of this array detector is made of a tantalum absorber bound, by indium bump hybridization, to a silicon thermistor. The absorber array is bound to the thermistor array in a single automatic step. The thermo-mechanical link, provided by hybridization, is being improved in terms of thermal capacitance. Finally, our main effort is in developing arrays of silicon thermistors with negligible excess 1/
f
noise. The thermistor has been simulated with the 2D simulator ATHENA (SILVACO International). We studied the effects of the implants and their thermal treatment on both vertical and lateral dopant distributions at the edges of the thermistor. Prototypes have been created following the procedure optimized by the ATHENA simulation. We present the status of the development and results of measurements performed on these four main building blocks required to create a detector array up to 32×32 pixels in size.
Recent validation tests of the Edelweiss II detector holders Schwamm, F.; Chapellier, M.; Hervé, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2006, Letnik:
559, Številka:
2
Journal Article
Recenzirano
A very good understanding of noise sources is highly important for the sensitivity of a dark matter search experiment. One of these noise contributions in the Edelweiss experiment could be the ...microphonics and temperature variations caused by vibrations of the cryostat. Recent studies complement an earlier work in describing the effect of the Edelweiss II detector holders on the amplitude of the vibrations seen by the detector. The results of these studies will be presented in this article.
The EDELWEISS Collaboration is searching for WIMP dark matter using natural Ge cryogenic detectors. The whole data set of the first phase of the experiment contains a fiducial exposure of 4.8 kg day ...on 73Ge, the naturally present (7.8%), high-spin Ge isotope. The sensitivity of the experiment to the spin-dependent WIMP-nucleon interactions is evaluated using the model-independent framework proposed by Tovey et al. Phys. Lett. B 488 (2000) 17. It is shown that the EDELWEISS sensitivity for the WIMP-neutron coupling is competitive when compared with results of other spin-sensitive WIMP dark matter experiments. The current experimental limits lie however two orders of magnitude higher than the most optimistic SUSY models.
The LUMINEU is designed to investigate the possibility to search for neutrinoless double beta decay in 100 Mo by means of a large array of scintillating bolometers based on ZnMoO4 crystals enriched ...in 100 Mo. High energy resolution and relatively fast detectors, which are able to measure both the light and the heat generated upon the interaction of a particle in a crystal, are very promising for the recognition and rejection of background events. We present the LUMINEU concepts and the experimental results achieved aboveground and underground with large-mass natural and enriched crystals. The measured energy resolution, the α/β discrimination power and the radioactive internal contamination are all within the specifications for the projected final LUMINEU sensitivity. Simulations and preliminary results confirm that the LUMINEU technology can reach zero background in the region of interest (around 3 MeV) with exposures of the order of hundreds kgxyears, setting the bases for a next generation 0v2β decay experiment capable to explore the inverted hierarchy region of the neutrino mass pattern.
The first phase of the EDELWEISS-II Dark Matter search is under construction. In this phase, 23 detectors with NTD thermal sensors are going to be used for the direct detection of WIMPs. In this ...paper, we are describing the production, mounting, monitoring and storage techniques, together with the different characteristics of the detectors and their variations.
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