We present the first Ge-based constraints on sub-MeV /c2 dark matter (DM) particles interacting with electrons using a 33.4 g Ge cryogenic detector with a 0.53 electron-hole pair (rms) resolution, ...operated underground at the Laboratoire Souterrain de Modane. Competitive constraints are set on the DM-electron scattering cross section, as well as on the kinetic mixing parameter of dark photons down to 1 eV / c2. In particular, the most stringent limits are set for dark photon DM in the 6 to 9 eV / c2 range. These results demonstrate the high relevance of Ge cryogenic detectors for the search of DM-induced eV-scale electron signals.
We present the noise performance of high electron mobility transistors (HEMT) developed by CNRS/C2N laboratory. Various HEMT’s gate geometries with 2 pF to 230 pF input capacitance have been studied ...at 4 K. A model for both voltage and current noises has been developed with frequency dependence up to 1 MHz. These HEMTs exhibit low dissipation, excellent noise performance and can advantageously replace traditional Si-JFETs for the readout of high impedance thermal sensor and semiconductor ionization cryogenic detectors. Our model predicts that cryogenic germanium detectors of 30 g with 10 eV heat and 20 eV
ee
baseline resolution are feasible if read out by HEMT-based amplifiers. Such resolution allows for high discrimination between nuclear and electron recoils at low threshold. This capability is of major interest for coherent elastic neutrino scattering and low-mass dark matter experiments such as Ricochet and EDELWEISS.
The
Ricochet
reactor neutrino observatory is planned to be installed at Institut Laue–Langevin starting in mid-2022. The scientific goal of the
Ricochet
collaboration is to perform a low-energy and ...percentage precision CENNS measurement in order to explore exotic physics scenarios beyond the standard model. To that end,
Ricochet
will host two cryogenic detector arrays: the CryoCube (Ge target) and the Q-ARRAY (Zn target), both with unprecedented sensitivity to
O
(10) eV nuclear recoils. The CryoCube will be composed of 27 Ge crystals of 38 g instrumented with NTD-Ge thermal sensor as well as aluminum electrodes operated at 10 mK in order to measure both the ionization and the heat energies arising from a particle interaction. To be a competitive CENNS detector, the CryoCube array is designed with the following specifications: a low-energy threshold (
∼
50
eV), the ability to identify and reject with a high efficiency the overwhelming electromagnetic backgrounds (gamma, beta, and X-rays), and a sufficient payload (
∼
1
kg). After a brief introduction of the future
Ricochet
experiment and its CryoCube, the current works and first performance results on the optimization of the heat channel, and the electrode designs will be presented. We conclude with a preliminary estimation of the CryoCube sensitivity to the CENNS signal within
Ricochet
.
The R
icochet
reactor neutrino observatory is planned to be installed at the Laue Langevin Institute starting mid-2022. Its scientific goal is to perform a low-energy and high precision measurement ...of the coherent elastic neutrino-nucleus scattering spectrum in order to explore exotic physics scenarios. R
icochet
will host two cryogenic detector arrays: the CryoCube (Ge target) and the Q-
array
(Zn target), operated at 10 mK. The 1 kg Ge CryoCube will consist of 27 Ge crystals instrumented with NTD-Ge thermal sensors and charge collection electrodes for a simultaneous heat and ionization readout to reject the electromagnetic backgrounds (gamma, beta, x-rays). We present the status of its front-end electronics. The first stage of amplification is made of High Electron Mobility Transistors developed by CNRS/C2N laboratory, optimized to achieve ultra-low noise performance at 1 K with a dissipation as low as 15
μ
W per channel. Our noise model predicts that 10 eV heat and 20 eV
ee
RMS baseline resolutions are feasible with a high dynamic range for the deposited energy (up to 10 MeV) thanks to loop amplification schemes. Such resolutions are mandatory to have a high discrimination power between nuclear and electron recoils at the lowest energies.
High Impedance TES Bolometers for EDELWEISS Marnieros, S.; Armengaud, E.; Arnaud, Q. ...
Journal of low temperature physics,
06/2023, Letnik:
211, Številka:
5-6
Journal Article
Recenzirano
Odprti dostop
The EDELWEISS collaboration aims for direct detection of light dark matter using germanium cryogenic detectors with low threshold phonon sensor technologies and efficient charge readout designs. We ...describe here the development of Ge bolometers equipped with high impedance thermistors based on a Nb
x
Si
1−x
TES alloy. High aspect ratio spiral designs allow the TES impedance to match with JFET or HEMT front-end amplifiers. We detail the behavior of the superconducting transition properties of these sensors and the detector optimization in terms of sensitivity to a-thermal phonons. We report preliminary results of a 200 g Ge detector that was calibrated using
71
Ge activation by neutrons at the LSM underground laboratory.
The dry cryostat technology is based on pulse tube cryo-coolers and offers a good alternative to wet dilution cryostats. However, the main drawback is the production of vibrations induced by the ...pulse tube. These vibrations can be transmitted to the cryogenic detectors mounted in the cryostat and cause extra-noises dramatically affecting their performance. A solution to mitigate the impact of these vibrations is to mount the detectors on a suspended tower. For this purpose, vibrations in a dry cryostat were modeled and preliminary prototypes were investigated in the scope of R&D for the EDELWEISS-III experiment.
The EDELWEISS Collaboration has performed a search for dark matter particles with masses below the GeV scale with a 33.4-g germanium cryogenic detector operated in a surface lab. The energy deposits ...were measured using a neutron-transmutation-doped Ge thermal sensor with a 17.7 eV (rms) baseline heat energy resolution leading to a 60 eV analysis energy threshold. Despite a moderate lead shielding and the high-background environment, the first sub-GeV spin-independent dark matter limit based on a germanium target has been achieved. The experiment provides the most stringent, nuclear-recoil-based, above-ground limit on spin-independent interactions above 600 MeV/c2. The experiment also provides the most stringent limits on spin-dependent interactions with protons and neutrons below 1.3 GeV/c2. Furthermore, the dark matter search results were studied in the context of strongly interacting massive particles, taking into account Earth-shielding effects, for which new regions of the available parameter space have been excluded. Finally, the dark matter search has also been extended to interactions via the Migdal effect, resulting for the first time in the exclusion of particles with masses between 45 and 150 MeV/c2 with spin-independent cross sections ranging from 10−29 to 10−26 cm2.
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