The EDELWEISS Collaboration has performed a direct search for WIMP dark matter using a 320 g heat-and-ionization cryogenic Ge detector operated in a low-background environment in the Laboratoire ...Souterrain de Modane. No nuclear recoils are observed in the fiducial volume in the 30–200 keV energy range during an effective exposure of 4.53 kg
day. Limits for the cross-section for the spin-independent interaction of WIMPs and nucleons are set in the framework of the Minimal Supersymmetric Standard Model (MSSM). The central value of the signal reported by the experiment DAMA is excluded at 90% CL.
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.
Measurements of the background neutron environment, at a depth of 1780 m (4800 mwe) in the Underground Laboratory of Modane (L.S.M.) are reported. Using a
6Li liquid scintillator, the energy spectrum ...of the fast neutron flux has been determined. Monte Carlo calculations of the (α,
n) and spontaneous fission processes in the surrounding rock has been performed and compared to the experimental result. In addition, using two
3He neutron counters, the thermal neutron flux has been measured.
The EDELWEISS-II Collaboration has completed a direct search for WIMP dark matter with an array of ten 400-g cryogenic germanium detectors in operation at the Laboratoire Souterrain de Modane. The ...combined use of thermal phonon sensors and charge collection electrodes with an interleaved geometry enables the efficient rejection of γ-induced radioactivity as well as near-surface interactions. A total effective exposure of 384 kg d has been achieved, mostly coming from fourteen months of continuous operation. Five nuclear recoil candidates are observed above 20 keV, while the estimated background is 3.0 events. The result is interpreted in terms of limits on the cross-section of spin-independent interactions of WIMPs and nucleons. A cross-section of 4.4×10−8 pb is excluded at 90%CL for a WIMP mass of 85 GeV. New constraints are also set on models where the WIMP-nucleon scattering is inelastic.
CUPID-Mo, located in the Laboratoire Souterrain de Modane (France), was a demonstrator for the next generation
0
ν
β
β
decay experiment, CUPID. It consisted of an array of 20 enriched Li
2
100
MoO
4
...bolometers and 20 Ge light detectors and has demonstrated that the technology of scintillating bolometers with particle identification capabilities is mature. Furthermore, CUPID-Mo can inform and validate the background prediction for CUPID. In this paper, we present a detailed model of the CUPID-Mo backgrounds. This model is able to describe well the features of the experimental data and enables studies of the
2
ν
β
β
decay and other processes with high precision. We also measure the radio-purity of the Li
2
100
MoO
4
crystals which are found to be sufficient for the CUPID goals. Finally, we also obtain a background index in the region of interest of 3.7
-
0.8
+
0.9
(stat)
-
0.7
+
1.5
(syst)
×
10
-
3
counts/
Δ
E
FWHM
/
mol
iso
/
year
,
the lowest in a bolometric
0
ν
β
β
decay experiment.
Abstract
CUPID-Mo, located in the Laboratoire Souterrain de Modane (France), was a demonstrator for the next generation
$$0\nu \beta \beta $$
0
ν
β
β
decay experiment, CUPID. It consisted of an array ...of 20 enriched Li
$$_{2}$$
2
$$^{100}$$
100
MoO
$$_4$$
4
bolometers and 20 Ge light detectors and has demonstrated that the technology of scintillating bolometers with particle identification capabilities is mature. Furthermore, CUPID-Mo can inform and validate the background prediction for CUPID. In this paper, we present a detailed model of the CUPID-Mo backgrounds. This model is able to describe well the features of the experimental data and enables studies of the
$$2\nu \beta \beta $$
2
ν
β
β
decay and other processes with high precision. We also measure the radio-purity of the Li
$$_{2}$$
2
$$^{100}$$
100
MoO
$$_4$$
4
crystals which are found to be sufficient for the CUPID goals. Finally, we also obtain a background index in the region of interest of 3.7
$$^{+0.9}_{-0.8}$$
-
0.8
+
0.9
(stat)
$$^{+1.5}_{-0.7}$$
-
0.7
+
1.5
(syst)
$$\times ~10 ^{-3}$$
×
10
-
3
counts/
$$\Delta E_{\text {FWHM}}/\text {mol}_{\text {iso}}/\text {year},$$
Δ
E
FWHM
/
mol
iso
/
year
,
the lowest in a bolometric
$$0\nu \beta \beta $$
0
ν
β
β
decay experiment.
The future
Ricochet
experiment aims to search for new physics in the electroweak sector by measuring the Coherent Elastic Neutrino-Nucleus Scattering process from reactor antineutrinos with high ...precision down to the sub-100 eV nuclear recoil energy range. While the
Ricochet
collaboration is currently building the experimental setup at the reactor site, it is also finalizing the cryogenic detector arrays that will be integrated into the cryostat at the Institut Laue Langevin in early 2024. In this paper, we report on recent progress from the Ge cryogenic detector technology, called the CryoCube. More specifically, we present the first demonstration of a 30 eVee (electron equivalent) baseline ionization resolution (RMS) achieved with an early design of the detector assembly and its dedicated High Electron Mobility Transistor (HEMT) based front-end electronics with a total input capacitance of about 40 pF. This represents an order of magnitude improvement over the best ionization resolutions obtained on similar phonon-and-ionization germanium cryogenic detectors from the EDELWEISS and SuperCDMS dark matter experiments, and a factor of three improvement compared to the first fully-cryogenic HEMT-based preamplifier coupled to a CDMS-II germanium detector with a total input capacitance of 250 pF. Additionally, we discuss the implications of these results in the context of the future
Ricochet
experiment and its expected background mitigation performance.
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