We present the performances of a 330 g zinc molybdate (ZnMoO
4
) crystal working as scintillating bolometer as a possible candidate for a next generation experiment to search for neutrinoless double ...beta decay of
100
Mo. The energy resolution, evaluated at the 2615 keV
γ
-line of
208
Tl, is 6.3 keV FWHM. The internal radioactive contaminations of the ZnMoO
4
were evaluated as <6 μBq/kg (
228
Th) and 27±6 μBq/kg (
226
Ra). We also present the results of the
α
vs
β
/
γ
discrimination, obtained through the scintillation light as well as through the study of the shape of the thermal signal alone.
We report the final result of the CUORICINO experiment. Operated between 2003 and 2008, with a total exposure of 19.75 kg*y of Te, CUORICINO was able to set a lower bound on the Te Ovββhalf-life of ...2.8 ×10years at 90% C.L. The limit here reported includes the effects of systematic uncertainties that are examined in detail in the paper. The corresponding upper bound on the neutrino Majorana mass is in the range 300-710 meV, depending on the adopted nuclear matrix element evaluation.
Abstract
CUPID-0 is the first pilot experiment of CUPID, a next-generation project searching for neutrinoless double beta decay. In its first scientific run, CUPID-0 operated 26 ZnSe cryogenic ...calorimeters coupled to light detectors in the underground Laboratori Nazionali del Gran Sasso. In this work, we analyzed a ZnSe exposure of 11.34 kg year to search for the neutrinoless double beta decay of
$$^{70}$$
70
Zn and for the neutrinoless positron-emitting electron capture of
$$^{64}$$
64
Zn. We found no evidence for these decays and set 90
$$\%$$
%
credible interval limits of
$$\hbox {T}_{1/2}^{0\nu \beta \beta }$$
T
1
/
2
0
ν
β
β
(
$$^{70}$$
70
Zn) > 1.6
$$10^{21}$$
10
21
year and
$$\hbox {T}_{1/2}^{0\nu EC \beta +}$$
T
1
/
2
0
ν
E
C
β
+
(
$$^{64}$$
64
Zn) > 1.2
$$\times 10^{22}$$
×
10
22
year, surpassing by more than one order of magnitude the previous experimental results (Belli et al. in J Phys G 38(11):115107,
https://doi.org/10.1088/0954-3899/38/11/115107
, 2011).
CUORE, an array of 988 TeO
2
bolometers, is about to be one of the most sensitive experiments searching for neutrinoless double-beta decay. Its sensitivity could be further improved by removing the ...background from
α
radioactivity. A few years ago it was pointed out that the signal from
β
s can be tagged by detecting the emitted Cherenkov light, which is not produced by
α
s. In this paper we confirm this possibility. For the first time we measured the Cherenkov light emitted by a CUORE crystal, and found it to be 100 eV at the
Q
-value of the decay. To completely reject the
α
background, we compute that one needs light detectors with baseline noise below 20 eV RMS, a value which is 3–4 times smaller than the average noise of the bolometric light detectors we are using. We point out that an improved light detector technology must be developed to obtain TeO
2
bolometric experiments able to probe the inverted hierarchy of neutrino masses.
The projected background for the CUORE experiment Alduino, C.; Avignone, F. T.; Azzolini, O. ...
European physical journal. C, Particles and fields,
08/2017, Letnik:
77, Številka:
8
Journal Article
Recenzirano
Odprti dostop
The Cryogenic Underground Observatory for Rare Events (CUORE) is designed to search for neutrinoless double beta decay of
130
Te with an array of 988 TeO
2
bolometers operating at temperatures ...around 10 mK. The experiment is currently being commissioned in Hall A of Laboratori Nazionali del Gran Sasso, Italy. The goal of CUORE is to reach a 90% C.L. exclusion sensitivity on the
130
Te decay half-life of 9
×
10
25
years after 5 years of data taking. The main issue to be addressed to accomplish this aim is the rate of background events in the region of interest, which must not be higher than 10
-
2
counts/keV/kg/year. We developed a detailed Monte Carlo simulation, based on results from a campaign of material screening, radioassays, and bolometric measurements, to evaluate the expected background. This was used over the years to guide the construction strategies of the experiment and we use it here to project a background model for CUORE. In this paper we report the results of our study and our expectations for the background rate in the energy region where the peak signature of neutrinoless double beta decay of
130
Te is expected.
CUPID-0 is the first pilot experiment of CUPID, a next-generation project searching for neutrinoless double beta decay. In its first scientific run, CUPID-0 operated 26 ZnSe cryogenic calorimeters ...coupled to light detectors in the underground Laboratori Nazionali del Gran Sasso. In this work, we analyzed a ZnSe exposure of 11.34 kg year to search for the neutrinoless double beta decay of
70
Zn and for the neutrinoless positron-emitting electron capture of
64
Zn. We found no evidence for these decays and set 90
%
credible interval limits of
T
1
/
2
0
ν
β
β
(
70
Zn) > 1.6
10
21
year and
T
1
/
2
0
ν
E
C
β
+
(
64
Zn) > 1.2
×
10
22
year, surpassing by more than one order of magnitude the previous experimental results (Belli et al. in J Phys G 38(11):115107,
https://doi.org/10.1088/0954-3899/38/11/115107
, 2011).
We report on the development of thermal kinetic inductance detectors (TKIDs) suitable to perform X-ray spectroscopy measurements. The aim is to implement MKIDs sensors working in thermal ...quasi-equilibrium mode to detect X-ray photons as pure calorimeters. The thermal mode is a variation on the MKID classical way of operation that has generated interest in recent years. TKIDs can offer the MKIDs inherent multiplexibility in the frequency domain, a high spatial resolution comparable with CCDs, and an energy resolution theoretically limited only by thermodynamic fluctuations across the thermal weak links. Microresonators are built in Ti/TiN multilayer technology with the inductive part thermally coupled with a metal absorber on a suspended SiN membrane, to avoid escape of phonons from the film to the substrate. The mid-term goal is to optimize the single-pixel design in terms of superconducting critical temperatures, internal quality factors, kinetic inductance and spectral energy resolution. The final goal is to realize a demonstrator array for a next generation thousand pixels X-ray spectrometer. In this contribution, the status of the project after one year of developments is reported, with detailed reference to the microresonators design and simulations and to the fabrication process.
BULLKID is an R&D project on a cryogenic particle detector to search for rare low-energy processes such as low-mass dark matter and neutrino coherent scattering off nuclei. The detector unit we are ...designing consists in an array of ~ 100 silicon absorbers sensed by phonon-mediated, microwave-multiplexed kinetic inductance detectors, with energy threshold below 100 eV and total target mass around 30 g. The single detector unit will be engineered to ensure a straightforward scalability to a future kg-scale experiment.
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