Searching for the β+EC and EC/EC Decays of 74Se Rukhadze, N. I.; Barabash, A. S.; Brudanin, V. B. ...
Bulletin of the Russian Academy of Sciences. Physics,
08/2020, Letnik:
84, Številka:
8
Journal Article
Recenzirano
Double beta decay (β
+
EC, EC/EC) of
74
Se was investigated at the Modane underground laboratory (LSM, France; 4800 m of water equivalent) using the OBELIX ultralow-background HPGe detector with a ...sensitive volume of 600 cm
3
and a sample of natural selenium with a mass of 1.6 kg containing ~0.89% (~14.24 g) of
74
Se. The new experimental limits for β
+
EC and EC/EC decays of
74
Se to ground 0
+
and excited
596 keV, and
1204 keV states of
74
Ge, were obtained from experimental data accumulated over 135 days.
Investigating the Double Beta Decay of 58Ni Rukhadze, N. I.; Brudanin, V. B.; Klimenko, A. A. ...
Bulletin of the Russian Academy of Sciences. Physics,
06/2018, Letnik:
82, Številka:
6
Journal Article
Recenzirano
Double beta decay (β +
EC
,
EC/EC
) of
58
Ni is investigated at France’s Modane Underground Laboratory (4800 m water equivalent) using the OBELIX ultralow-background HPGe detector with a sensitive ...volume of 600 cm
3
and a natural nickel sample of ~68% 58Ni with a mass of ~21.7 kg. After preliminary analysis of the experimental data accumulated over ~144 days, new experimental limits are obtained for the 2νβ
+
EC
decay of
58
Ni to the 0
+
ground state and the 2
1
+
, 811 keV excited state of
58
Fe, and for the 2ν
EC/EC
decay of
58
Ni to the 2
1
+
, 811 keV and 2
2
+
, 1675 keV excited states of
58
Fe. The limits are
T
1/2
(β
+
EC
,0→0
+
) > 1.7 × 10
22
yr,
T
1/2
(β
+
EC
,0→2
1
+
) > 2.3 × 10
22
yr,
T
1/2
(
EC/EC
,0→2
1
+
) > 3.3 × 10
22
yr, and
T
1/2
(
EC/EC
,0→2
2
+
) > 3.4 × 10
22
yr. Experimental limit T
1/2
(0ν
EC/EC
–res, 1918 keV > 4.1 × 10
22
yr is obtained for resonant neutrinoless radiative EC/EC decay with an energy of 1918.3 keV. All limits are at 90% CL.
Investigation of double beta decay processes (β+EC, EC/EC) of 58Ni was performed at the Modane underground laboratory (LSM, France, 4800 m w.e.). A sample of natural nickel, containing ∼68% of 58Ni ...and a mass of ∼21.7 kg, was measured using ultra low-background HPGe detector Obelix (sensitive volume of 600 cm3) during ∼143.8 days. New experimental limits on 2νβ+EC decay of 58Ni to the ground 0+ and (math), 811 keV excited state of 58Fe, and 2νEC/EC decay of 58Ni to (math), 811 keV and (maht), 1 675 keV excited states of 58Fe were obtained in this measurement. There are -T1/2(β+EC, 0+ → 0+) > 1.7 × 1022 y; (math), (math), (math). For resonant neutrino-less radiative EC/EC decay with energy of 1 918.3 keV a new experimental limit of T1/2 (0νEC/EC - res, 1918KeV) > 4.1 ×1022 y was also obtained. All limits are at 90 % CL.
A new experiment devoted to searches for double electron capture in Cd-106 decay is being performed at the Modane underground laboratory (4800 mwe) with the 32-detector TGV-2 spectrometer. The limit ...T (1/2)(2 nu EC/EC) > 2.0x10(20) yr at a 90%confidence level (C.L.) was obtained from a preliminary analysis of data obtained over 2250 h of measurements with about 23.2 g sample enriched in the isotope Cd-106 to 99.57%. The limits T (1/2)(KL, 2741 keV) > 0.9 x 10(20) yr and T (1/2)(KK, 2718 keV) a parts per thousand << 1.4 x 10(20) yr at a 90% C.L. on the neutrinoless decay of Cd-106 were obtained from measurements performed with the Obelix low-background spectrometer from high-purity germanium (HPGe spectrometer) for a sample of mass about 23.2 g enriched in the isotope Cd-106.
Abstract
The III phase of experiment TGV-2 to search for β
+
β
+
, β+EC, EC/EC decay of
106
Cd was performed at the Modane underground laboratory (LSM, France, 4800 m w.e.). 16 foils (∼23.2 g) of ...enriched
106
Cd were measured using the 32-detector low background HPGe spectrometer TGV-2 during 42500 h. New limit on 2
ν
EC/EC decay of
106
Cd to the ground 0
+
state of
106
Pd - T
1/2
> 7.2 × 10
20
y at 90% C.L was obtained. The limits on 2νβ
+
β
+
, 2νβ+EC decay of
106
Cd, and 2
ν
ECEC decay of
106
Cd to excited states of
106
Pd were significantly improved in comparison with previous phase II of the TGV-2 experiment.
A new experiment devoted to searches for double electron capture in sup.106Cd decay is being performed at the Modane underground laboratory (4800 mwe) with the 32-detector TGV-2 spectrometer. The ...limit T.sub.1/2 (2υEC/EC) > 2.0 x 10.sup.20 yr at a 90% confidence level (C.L.) was obtained from a preliminary analysis of data obtained over 2250 h of measurements with about 23.2 g sample enriched in the isotope sup.106Cd to 99.57%. The limits T.sub.1/2(KL 2741 keV) > 0.9 x 10.sup.20 yr and T.sub.1/2(KK 2718 keV) >> 1.4 x 10.sup.20yr at a 90% C.L. on the neutrinoless decay of sup.106Cd were obtained from measurements performed with the Obelix low-background spectrometer from high-purity germanium (HPGe spectrometer) for a sample of mass about 23.2 g enriched in the isotope sup.106Cd.
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