CUORE is a 1 ton scale cryogenic experiment aiming at the measurement of the Majorana mass of the electron neutrino. The detector is an array of 988 TeO
2 bolometers used for a calorimetric detection ...of the two electrons emitted in the
β
β
(
0
ν
)
of
130Te. The sensitivity of the experiment to the lowest Majorana mass is determined by the rate of background events that can mimic a
β
β
(
0
ν
)
. In this paper, we investigate the contribution of external sources i.e. environmental gammas, neutrons and cosmic ray muons to the CUORE background and show that the shielding setup designed for CUORE guarantees a reduction of this external background down to a level <10
−2
counts/kg
keV
yr at the
Q-value, as required by the physical goal of the experiment.
Rare event physics demands very detailed background control, high-performance detectors, and custom analysis strategies. Cryogenic calorimeters combine all these ingredients very effectively, ...representing a promising tool for next-generation experiments. CUPID-0 is one of the most advanced examples of such a technique, having demonstrated its potential with several results obtained with limited exposure. In this paper, we present a further application. Exploiting the analysis of delayed coincidence, we can identify the signals caused by the 220Rn-216Po decay sequence on an event-by-event basis. The analysis of these events allows us to extract the time differences between the two decays, leading to a new evaluation of 216Po half-life, estimated as (143.3±2.8) ms.
The CUPID-0 experiment searches for double beta decay using cryogenic calorimeters with double (heat and light) read-out. The detector, consisting of 24 ZnSe crystals 95
enriched in
Se and two ...natural ZnSe crystals, started data-taking in 2017 at Laboratori Nazionali del Gran Sasso. We present the search for the neutrino-less double beta decay of
Se into the 0
, 2
and 2
excited states of
Kr with an exposure of 5.74 kg
yr (2.24
10
emitters
yr). We found no evidence of the decays and set the most stringent limits on the widths of these processes:
(
Se
Kr
)8.55
10
yr
,
(
Se
Kr
)
yr
,
(
Se
Kr
)8.25
10
yr
(90
credible interval).
RES-NOVA is a newly proposed experiment for detecting neutrinos from astrophysical sources, mainly Supernovae, using an array of cryogenic detectors made of PbWO
4
crystals produced from ...archaeological Pb. This unconventional material, characterized by intrinsic high radiopurity, enables low-background levels in the region of interest for the neutrino detection via Coherent Elastic neutrino-Nucleus Scattering (CE
ν
NS). This signal lies at the detector energy threshold,
O
(1 keV), and it is expected to be hidden by naturally occurring radioactive contaminants of the crystal absorber. Here, we present the results of a radiopurity assay on a 0.84 kg PbWO
4
crystal produced from archaeological Pb operated as a cryogenic detector. The crystal internal radioactive contaminations are:
232
Th <40
μ
Bq/kg,
238
U <30
μ
Bq/kg,
226
Ra 1.3 mBq/kg and
210
Pb 22.5 mBq/kg. We also present a background projection for the final experiment and possible mitigation strategies for further background suppression. The achieved results demonstrate the feasibility of realizing this new class of detectors.
Core-collapse Supernovae (SNe) are one of the most energetic events in the Universe, during which almost all the star’s binding energy is released in the form of neutrinos. These particles are direct ...probes of the processes occurring in the stellar core and provide unique insights into the gravitational collapse. RES-NOVA will revolutionize how we detect neutrinos from astrophysical sources, by deploying the first ton-scale array of cryogenic detectors made from archaeological lead. Pb offers the highest neutrino interaction cross-section via coherent elastic neutrino-nucleus scattering (CEνNS). Such process will enable RES-NOVA to be equally sensitive to all neutrino flavours. For the first time, we propose the use archaeological Pb as sensitive target material in order to achieve an ultra-low background level in the region of interest (O(1 keV)). All these features make possible the deployment of the first cm-scale neutrino telescope for the investigation of astrophysical sources. In this contribution, we will characterize the radiopurity level and the performance of a small-scale proof-of-principle detector of RES-NOVA, consisting in a PbWO4 crystal made from archaeological-Pb operated as cryogenic detector.
•RES-NOVA: first-proposed cryogenic detector made from archaeological lead for background suppression.•Coherent elastic neutrino-nucleus scattering: innovative way to detect neutrinos from astrophysical sources.•Radiopurity level measured on kg-scale prototype allows supernovae neutrino detection.
The 1-ton-scale CUORE detector is made of 988
TeO
2
crystals operated as cryogenic bolometers at a working temperature of
∼
10
mK
. In order to provide the necessary cooling power at 4 K stage, a ...total of five pulse tube (PT) refrigerators are used. The PTs make the cryogenic system reliable and stable, but have the downside that mechanical vibrations at low frequencies (1.4 Hz and related harmonics) are injected into the experimental apparatus. An active noise cancellation technique has been developed in order to reduce such effect by taking advantage from the coherent interference of the pressure oscillations originated by the different PTs. The technique that will be presented consists in controlling the relative phases of the pressure waves running inside the CUORE PT lines, in order to achieve the lowest detector noise. By reducing the power of PT harmonics by a factor up to
10
4
, it drastically suppresses the overall noise RMS on the CUORE detector. In the following, we demonstrate the reliability and effectiveness of the technique, showing that the optimization of the detector noise level is possible in different experimental conditions.
Since the New Deal, labor has been a key member of the Democratic coalition. As unions decline, their centrality to the Democratic Party has also diminished. At the same time, state variation in ...party preferences, party strength, and the types of unions that remain has led some unions to become involved in Republican politics. In this manuscript we investigate how central unions are in party networks using state legislative donation data from 2000–2016. We find that union contributions are associated with increasing centrality to the Democratic Party, while business interest contributions are associated with unions being less central. Only union membership rates are related to labor’s position in the Republican network. This work has implications for how we consider which groups are under a party’s umbrella. While labor may spend more money, it cannot keep pace with business groups in the party coalition.
CRESST is a leading direct detection sub-GeVc−2 dark matter experiment. During its second phase, cryogenic bolometers were used to detect nuclear recoils off the CaWO4 target crystal nuclei. The ...previously established electromagnetic background model relies on Secular Equilibrium (SE) assumptions. In this work, a validation of SE is attempted by comparing two likelihood-based normalisation results using a recently developed spectral template normalisation method based on Bayesian likelihood. Albeit we find deviations from SE in some cases we conclude that these deviations are artefacts of the fit and that the assumptions of SE is physically meaningful.
•Novel assessment of secular equilibrium assumptions in a CaWO4 cryogenic crystal.•Bayesian likelihood normalisation method of spectral templates.•Comparison between fits with and without secular equilibrium assumptions.•Deviations found -> effects of the fit; SE assumptions validated.
The CRESST experiment uses cryogenic detectors based on transition-edge sensors to search for dark matter interactions. Each detector module consists of a scintillating CaWO
4
crystal and a ...silicon-on-sapphire (SOS) light detector which operate in coincidence (phonon-light technique). The 40-mm-diameter SOS disks (2 g mass) used in the data taking campaign of CRESST-II Phase 2 (2014–2016) reached absolute baseline resolutions of
σ
=
4–7 eV. This is the best performance reported for cryogenic light detectors of this size. Newly developed silicon beaker light detectors (4 cm height, 4 cm diameter, 6 g mass), which cover a large fraction of the target crystal surface, have achieved a baseline resolution of
σ
=
5.8
eV. First results of further improved light detectors developed for the ongoing low-threshold CRESST-III experiment are presented.
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