اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدNew limits on double beta processes in 106-Cd
64
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
A radiopure cadmium tungstate crystal scintillator, enriched in 106-Cd to 66%, with mass of 216 g (106-CdWO4) was used in coincidence with four ultra-low background HPGe detectors contained in a single cryostat to search for double beta decay processes in 106-Cd. New improved half-life limits on the double beta processes in 106-Cd have been set on the level of 1e20-1e21 yr after 13085 h of data taking deep underground (3600 m w.e.) at the Gran Sasso National Laboratories of INFN (Italy). In particular, the limit on the two neutrino electron capture with positron emission T1/2 >1.1e21 yr, has reached the region of theoretical predictions. The resonant neutrinoless double electron captures to the 2718, 2741 and 2748 keV excited states of 106-Pd are restricted on the level of T1/2 > 8.5e20 - 1.4e21 yr.
قيم البحث
اقرأ أيضاً
Double-beta processes in $^{184}$Os and $^{192}$Os were searched for over 15851 h at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N. by using a 118 g ultra-pure osmium sample installed on the endcap of a 112 cm$^3$ ultra-low-background broa
d-energy germanium detector. New limits on double-electron capture and electron capture with positron emission in $^{184}$Os were set at the level of $lim T_{1/2} sim 10^{16}-10^{17}$ yr. In particular the $2 u$2K and $2 u$KL decays of $^{184}$Os to the ground state of $^{184}$W are restricted as $T_{1/2}geq3.0times 10^{16}$ yr and $T_{1/2}geq2.0times 10^{16}$ yr, respectively. A lower limit on the half-life for the double-beta decay of $^{192}$Os to the first excited level of $^{192}$Pt was set as $lim T_{1/2}=2.0times 10^{20}$ yr at 90% C.L.
Studies on double beta decay processes in $^{106}$Cd were performed by using a cadmium tungstate scintillator enriched in $^{106}$Cd at 66% ($^{106}$CdWO$_4$) with two CdWO$_4$ scintillation counters (with natural Cd composition). No effect was obser
ved in the data accumulated over 26033 h. New improved half-life limits were set on the different channels and modes of the $^{106}$Cd double beta decay at level of $lim T_{1/2}sim 10^{20}-10^{22}$ yr. The limit for the two neutrino electron capture with positron emission in $^{106}$Cd to the ground state of $^{106}$Pd, $T^{2 umathrm{EC}beta^+}_{1/2}geq2.1times 10^{21}$ yr, was set by the analysis of the $^{106}$CdWO$_4$ data in coincidence with the energy release 511 keV in both CdWO$_4$ counters. The sensitivity approaches the theoretical predictions for the decay half-life that are in the range $T_{1/2}sim10^{21}-10^{22}$ yr. The resonant neutrinoless double-electron capture to the 2718 keV excited state of $^{106}$Pd is restricted at the level of $T^{0 umathrm{2K}}_{1/2}geq2.9times10^{21}$ yr
A radiopure cadmium tungstate crystal scintillator, enriched in $^{106}$Cd to 66%, with mass of 216 g ($^{106}$CdWO$_4$), was used to search for double beta decay processes in $^{106}$Cd in coincidence with four ultra-low background high purity germa
nium detectors in a single cryostat. New improved limits on the double beta processes in $^{106}$Cd have been set on the level of $10^{20}- 10^{21}$ yr after 13085 h of data taking. In particular, the half-life limit on the two neutrino electron capture with positron emission, $T_{1/2}^{2 uvarepsilonbeta^+}geq 1.1times 10^{21}$ yr, has reached the region of theoretical predictions. With this half-life limit the effective nuclear matrix element for the $2 uvarepsilonbeta^+$ decay is bounded as $M^{2 uvarepsilonbeta^+}_{eff}le 1.1$. The resonant neutrinoless double electron captures to the 2718 keV, 2741 keV and 2748 keV excited states of $^{106}$Pd are restricted at the level of $T_{1/2} geq (8.5times10^{20}-1.4times10^{21}$) yr.
We investigate several Pb$(n,ngamma$) and Ge$(n,ngamma$) reactions. We measure $gamma$-ray production from Pb$(n,ngamma$) reactions that can be a significant background for double-beta decay experiments which use lead as a massive inner shield. Parti
cularly worrisome for Ge-based double-beta decay experiments are the 2041-keV and 3062-keV $gamma$ rays produced via Pb$(n,ngamma$). The former is very close to the ^{76}Ge double-beta decay endpoint energy and the latter has a double escape peak energy near the endpoint. Excitation $gamma$-ray lines from Ge$(n,ngamma$) reactions are also observed. We consider the contribution of such backgrounds and their impact on the sensitivity of next-generation searches for neutrinoless double-beta decay using enriched germanium detectors.
New limits on $beta^+$EC and ECEC processes in $^{74}$Se have been obtained using a 600 cm$^3$ HPGe detector and an external source consisting of 1600 g of a natural selenium powder. For different $beta^+$EC and ECEC transitions (to the ground and ex
cited states) obtained limits are on the level $sim (0.2-4.8)times10^{19}$ yr at 90% C.L. In particular, for the potentially resonant transition into the 1204.2 keV excited state of $^{74}$Ge a lower half-life limit of $1.1times10^{19}$ yr at 90% C.L. has been obtained. Possibility to increase the sensitivity of such measurements is discussed.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
