Abstract
Plastic scintillators have become increasingly important in particle physics for time-of-flight and calorimetry measurements. Their light yield and the possibility of customizing their ...geometry make them also attractive for the construction of active vetoes in rare event physics experiments. For this purpose, some commercial plastic scintillators (purchased from Eljen Technology) were tested in cryogenic environments (liquid nitrogen and liquid helium). Their relative light yield was estimated by comparing the data acquired at room temperature with those acquired at cryogenic temperatures. Finally, estimates of the variation of the light yield at cryogenic temperatures were obtained.
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 Formula omitted enriched in ...Formula omittedSe 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 Formula omittedSe into the 0 Formula omitted, 2 Formula omitted and 2 Formula omitted excited states of Formula omittedKr with an exposure of 5.74 kg Formula omittedyr (2.24 Formula omitted10 Formula omitted emitters Formula omittedyr). We found no evidence of the decays and set the most stringent limits on the widths of these processes: Formula omitted( Formula omittedSe Formula omittedKr Formula omitted)8.55 Formula omitted10 Formula omitted yr Formula omitted, Formula omitted ( Formula omitted Se Formula omitted Kr Formula omitted) Formula omitted yr Formula omitted, Formula omitted( Formula omittedSe Formula omittedKr Formula omitted)8.25 Formula omitted10 Formula omitted yr Formula omitted (90 Formula omitted credible interval).
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract Sterile neutrinos in the keV mass range present a viable candidate for dark matter. They can be detected through single β -decay, where they cause small spectral distortions. The Karlsruhe ...Tritium Neutrino (KATRIN) experiment aims to search for keV-scale sterile neutrinos with high sensitivity. To achieve this, the KATRIN beamline will be equipped with a novel multi-pixel silicon drift detector focal plane array named TRISTAN. In this study, we present the performance of a TRISTAN detector module, a component of the eventual 9-module system. Our investigation encompasses spectroscopic aspects such as noise performance, energy resolution, linearity, and stability.
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).
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Localization and modeling of radioactive contaminations is a challenge that ultra-low background experiments are constantly facing. These are fundamental steps both to extract scientific results and ...to further reduce the background of the detectors. Here we present an innovative technique based on the analysis of
α
-
α
delayed coincidences in
232
Th and
238
U decay chains, developed to investigate the contaminations of the ZnSe crystals in the CUPID-0 experiment. This method allows to disentangle surface and bulk contaminations of the detectors relying on the different probability to tag delayed coincidences as function of the
α
decay position.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
The TRISTAN project is the upgrade of the KATRIN experiment designed for the search of sterile neutrinos by replacing the current KATRIN detector with a multipixel SDD (Silicon Drift ...Detector) matrix. We have characterized SDDs response to electrons using a SEM (Scanning Electron Microscope) as an electron source and a Geant4-based simulation whose output is processed with an empirical function to reproduce data. We have crosschecked this model by reconstructing backscattering measurements obtained using a radioactive electron source.
Abstract The TRISTAN detector is a new detector for electron spectroscopy at the Karlsruhe Tritium Neutrino (KATRIN) experiment. The semiconductor detector utilizes the silicon drift detector ...technology and will enable the precise measurement of the entire tritium β -decay electron spectrum. Thus, a significant fraction of the parameter space of potential neutrino mass eigenstates in the keV-mass regime can be probed. We developed a custom electron gun based on the effect of thermionic emission to characterize the TRISTAN detector modules with mono-energetic electrons before installation into the KATRIN beamline. The electron gun provides an electron beam with up to 25 keV kinetic energy and an electron rate in the order of 10 5 electrons per second. This manuscript gives an overview of the design and commissioning of the electron gun. In addition, we will shortly discuss a first measurement with the electron gun to characterize the electron response of the TRISTAN detector.
Neutrinoless double-beta (0vββ) decay is a hypothesized lepton-number-violating process that offers the only known means of asserting the possible Majorana nature of neutrino mass. The Cryogenic ...Underground Observatory for Rare Events (CUORE) is an upcoming experiment designed to search for 0vββ decay of sup.130Te using an array of 988 TeO.sub.2 crystal bolometers operated at 10 mK. The detector will contain 206 kg of sup.130Te and have an average energy resolution of 5 keV; the projected 0vββ decay half-life sensitivity after five years of livetime is 1.6 x 10.sup.26 γ at 1σ (9.5 x 10.sup.25 γ at the 90% confidence level), which corresponds to an upper limit on the effective Majorana mass in the range 40-100 meV (50-130 meV). In this paper, we review the experimental techniques used in CUORE as well as its current status and anticipated physics reach.
Next-generation experiments searching for rare events must satisfy increasingly stringent requirements on the bulk and surface radioactive contamination of their active and structural materials. The ...measurement of surface contamination is particularly challenging, as no existing technology is capable of separately measuring parts of the 232Th and 238U decay chains that are commonly found to be out of secular equilibrium. We will present the results obtained with a detector prototype consisting of 8 silicon wafers of 150 mm diameter instrumented as bolometers and operated in a low-background dilution refrigerator at the Gran Sasso Underground Laboratory of INFN, Italy. The prototype was characterized by a baseline energy resolution of few keV and a background <100 nBq/cm2 in the full range of α energies, obtained with simple procedures for cleaning of all employed materials and no specific measures to prevent recontamination. Such performance, together with the modularity of the detector design, demonstrate the possibility to realize an alpha detector capable of separately measuring all alpha emitters of the 232Th and 238U chains, possibly reaching a sensitivity of few nBq/cm2.
•Material screening.•Bolometric alpha detector.•Low-radioactivity measurements.
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