arXiv subjects

D. M. Chernyak

Publications and source records attributed to D. M. Chernyak.

23 records · Page 2Linked to original sources

arXiv2013

CdWO4 crystal scintillators from enriched isotopes for double beta decay experiments

Cadmium tungstate crystal scintillators enriched in 106Cd and 116Cd were developed. The produced scintillators exhibit good optical and scintillation properties, and a low level of radioactive contamination. Experiments to search for double beta decay of 106Cd and 116Cd are in progress at the Gran Sasso National Laboratories of the INFN (Italy). Prospects to further improve the radiopurity of the detectors by recrystallization are discussed.

physics.ins-det↗

arXiv2013

Random coincidence of $2\nu2β$ decay events as a background source in bolometric $0\nu2β$ decay experiments

Two neutrino double $β$ decay can create irremovable background even in high energy resolution detectors searching for neutrinoless double $β$ decay due to random coincidence of $2\nu2β$ events in case of poor time resolution. Possibilities to suppress this background in cryogenic scintillating bolometers are discussed. It is shown that the present bolometric detector technologies enable to control this form of background at the level required to explore the inverted hierarchy of the neutrino mass pattern, including the case of bolometers searching for the neutrinoless double $β$ decay of $^{100}$Mo, which is characterized by a relatively short two neutrino double $β$ decay half-life.

physics.ins-det↗

arXiv2012

Search for double beta decay processes in 106Cd with the help of 106CdWO4 crystal scintillator

A search for the double beta processes in 106Cd was carried out at the Gran Sasso National Laboratories of the INFN (Italy) with the help of a 106CdWO4 crystal scintillator (215 g) enriched in 106Cd up to 66%. After 6590 h of data taking, new improved half-life limits on the double beta processes in 106Cd were established at the level of 10^{19}-10^{21} yr; in particular, T_{1/2}(2νεβ^+) > 2.1 10^{20} yr, T_{1/2}(2ν2β^+) > 4.3 10^{20} yr, and T_{1/2}(0ν2ε) > 1.0 10^{21} yr. The resonant neutrinoless double electron captures to the 2718 keV, 2741 keV and 2748 keV excited states of 106Pd are restricted to T_{1/2}(0ν2K) > 4.3 10^{20} yr, T_{1/2}(0νKL1) > 9.5 10^{20} yr and T_{1/2}(0νKL3) > 4.3 10^{20} yr, respectively (all limits at 90% C.L.). A possible resonant enhancement of the 0ν2εprocesses is estimated in the framework of the QRPA approach. The radioactive contamination of the 106CdWO4 crystal scintillator is reported.

nucl-ex↗

arXiv2012

Searches for neutrinoless resonant double electron captures at LNGS

Several experiments were performed during last years at underground (3600 m w.e.) Laboratori Nazionali del Gran Sasso (LNGS) of the INFN (Italy) to search for resonant 2$\varepsilon0ν$ captures in 96Ru, 106Cd, 136Ce, 156Dy, 158Dy, 180W, 184Os, 190Pt with the help of HP Ge semiconductor detectors, and ZnWO4 and 106CdWO4 crystal scintillators. No evidence for r-2$\varepsilon0ν$ decays was found, and only T_{1/2} limits were established in the range of 10^{14}-10^{21} yr.

nucl-ex↗

arXiv2011

Low background detector with enriched 116CdWO4 crystal scintillators to search for double beta decay of 116Cd

A cadmium tungstate crystal boule enriched in $^{116}$Cd to 82% with mass of 1868 g was grown by the low-thermal-gradient Czochralski technique. The isotopic composition of cadmium and the trace contamination of the crystal were estimated by High Resolution Inductively Coupled Plasma Mass-Spectrometry. The crystal scintillators produced from the boule were subjected to characterization that included measurements of transmittance and energy resolution. A low background scintillation detector with two $^{116}$CdWO$_4$ crystal scintillators (586 g and 589 g) was developed. The detector was running over 1727 h deep underground at the Gran Sasso National Laboratories of the INFN (Italy), which allowed to estimate the radioactive contamination of the enriched crystal scintillators. The radiopurity of a third $^{116}$CdWO$_4$ sample (326 g) was tested with the help of ultra-low background high purity germanium $γ$ detector. Monte Carlo simulations of double $β$ processes in $^{116}$Cd were used to estimate the sensitivity of an experiment to search for double $β$ decay of $^{116}$Cd.

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