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).
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Large-mass bolometers are today extensively used for dark matter and double beta decay searches, in both cases the ultimate experimental sensitivity is defined by the background level reached in such ...devices. The most common background sources and the techniques used for their identification and reduction are here reviewed, with a particular focus on double beta decay searches. The relevant role played by Monte Carlo simulations in this field is discussed. As a real case, the background optimization in the MiDBD experiment is described.
Final results of the CUPID-0 Phase I experiment Casali, N; Azzolini, O; Beeman, J W ...
Journal of physics. Conference series,
02/2020, Letnik:
1468, Številka:
1
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
A convincing observation of neutrino-less double beta decay (0vDBD) relies on the possibility of operating high-energy resolution detectors in background-free conditions. Scintillating cryogenic ...calorimeters are one of the most promising tools to fulfill the requirements for a next-generation experiment. Several steps have been taken to demonstrate the maturity of this technique, starting form the successful experience of CUPID-0. The CUPID-0 experiment collected almost 10 kg y of exposure, running 26 Zn82Se crystals during two years of continuous detector operation. The complete rejection of the dominant α background was demonstrated, measuring the lowest counting rate in the region of interest for this technique. Furthermore, the most stringent limit on the 82Se 0vDBD was established. In this contribution we present the final results of CUPID-0 phase-I, including a detailed model of the background and the measurement of the 2vDBD half-life.
In the framework of the CUPID-0 experiment, a numbers of ZnSe single crystals were produced and subjected to different thermal treatments, and later tested as cryogenic scintillating bolometers. We ...have found that a specific thermal treatment (24 hours under argon atmosphere at 900 °C) has a strong impact on some properties of ZnSe crystals (amplitude of signal, light yield, specific resistivity) and most interestingly, changes the quenching factor for alpha particles from values > 1 to values < 1. Thus such thermal treatment opens the possibility to modify this experimental parameter for a various applications.
A search for axioelectric absorption of solar axions produced in the
p
+
d
→
3
He
+
γ
(
5.5
MeV
)
reaction has been performed with a BGO detector placed in a low-background setup. A model-independent ...limit on the combination of axion–nucleon and axion–electron coupling constants has been obtained:
|
g
A
e
×
g
A
N
3
|
<
1.9
×
10
-
10
for 90 % confidence level. The constraint of the axion–electron coupling constant has been obtained for hadronic axion with masses of (0.1–1) MeV:
|
g
A
e
|
≤
(
0.96
-
8.2
)
×
10
-
8
.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The aim of this work was to develop a methodological approach based on Monte Carlo code for the neutronic analysis of the first core configuration of the TRIGA Mark II research reactor of the ...University of Pavia and the validation of the results by benchmarking with the experimental and operational data reported in the reactor Fist Criticality Final Report.
The neutron analysis was realised by means of the 3-D continuous-energy Monte Carlo code MCNP4C. The reactor model implemented represents in good detail all core components and allows the description of different core and fuel configurations with good versatility. Continuous-energy cross section data from ENDF/B-VI and ENDF/B-V and S(
α,
β) scattering functions from the ENDF/B-VI library were used. The results of the MCNP simulations and the experimental values show a very good agreement proving the goodness of the model.
The Cryogenic Underground Observatory for Rare Events (CUORE) experiment is presently in the final phases of its commissioning at the Gran Sasso Underground Laboratory (Italy). The CUORE cryogenic ...system will have to guarantee the optimal operation temperature of the detector (∼ 10 mK) for a live-time of 5 years. Furthermore, to avoid radioactive background, about 7 tonnes of lead are cooled to below 4 K and only few construction materials are acceptable. The CUORE detector will be by far the largest mass ever cooled to 10 mK. A description of the CUORE cryostat is presented and the specific characteristics and the performances are illustrated. The results of the (recently concluded) cryostat commissioning are also reported. They show that the CUORE cryostat is now ready to host the detector, thus confirming the possibility of realizing large bolometric arrays for rare event physics.
The R&D activity performed during the last years proved the potential of ZnSe scintillating bolometers to the search for neutrino-less double beta decay, motivating the realization of the first ...large-mass experiment based on this technology: CUPID-0. The isotopic enrichment in Formula: see textSe, the ZnFormula: see textSe crystals growth, as well as the light detectors production have been accomplished, and the experiment is now in construction at Laboratori Nazionali del Gran Sasso (Italy). In this paper we present the results obtained testing the first three ZnFormula: see textSe crystals operated as scintillating bolometers, and we prove that their performance in terms of energy resolution, background rejection capability and intrinsic radio-purity complies with the requirements of CUPID-0.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A methodological approach based on Monte Carlo code for the neutronic analysis of the TRIGA Mark II research reactor of the University of Pavia in the configuration of cold and clean nuclear fuel is ...presented. The complete implementation of the code is based on the construction characteristics with the validation of the results obtained by benchmarking the experimental and operational data reported in the reactor Fist Criticality Final Report. The 3-D continuous-energy Monte Carlo code MCNP5 was used. The description of the geometrical structure of the reactor core and the fuel configuration were designed with great accuracy and good detail. The comparison between simulated and measured data allows the creation of a complete reconstruction model of the TRIGA Mark II reactor.
•Monte Carlo model of a TRIGA Mark II reactor.•Reproduction of the reactor configuration after the first startup.•Simulation of critical configurations and control rod calibration curves.•Statistical and systematic error were accounted for.•Good agreement with experimental data proves model reliability.
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