天然存在的锇核素伴随γ量子的alpha decay的搜寻
Search for alpha decay of naturally occurring osmium nuclides accompanied by gamma quanta
摘要：
在INFN（意大利）的Gran Sasso国家实验室，使用体积为112 cm $^3$的超低背景宽能锗$γ$探测器和质量为118 g的超纯锇样品，对天然存在的锇同位素到子核的最低激发能级的$α$衰变进行了研究。锇样品的同位素组成已被测量与高精度使用负热电离质谱。在使用$γ$ -检测器采集15851小时的数据后，未检测到任何影响，并将$α$衰变的下限设定为$\lim T_{1/2}\sim 10^{15}-10^{19}$年。$^{184}$ Os和$^{186}$ Os的$α$衰变到子核第一激发能级的极限，$T_{1/2}(^{184}$ Os $)\geq 6.8\times10^{15}$ yr和$T_{1/2}(^{186}$ Os $)\geq3.3\times10^{17}$ yr（90% C.L.），超过了目前对衰变半衰期的理论估计。对于$^{189}$ Os和$^{192}$ Os，由于子体核素相对于$β$衰变的不稳定性，还寻找衰变到子体核的基态。
英文摘要：
A search for $α$ decay of naturally occurring osmium isotopes to the lowest excited levels of daughter nuclei has been performed by using an ultra-low-background Broad-Energy Germanium $γ$-detector with a volume of 112 cm$^3$ and an ultra-pure osmium sample with a mass of 118 g at the Gran Sasso National Laboratory of the INFN (Italy). The isotopic composition of the osmium sample has been measured with high precision using Negative Thermal Ionisation Mass Spectrometry. After 15851 h of data taking with the $γ$-detector no effect has been detected, and lower limits on the $α$ decays were set at level of $\lim T_{1/2}\sim 10^{15}-10^{19}$ yr. The limits for the $α$ decays of $^{184}$Os and $^{186}$Os to the first excited levels of daughter nuclei, $T_{1/2}(^{184}$Os$)\geq 6.8\times10^{15}$ yr and $T_{1/2}(^{186}$Os$)\geq3.3\times10^{17}$ yr (at 90% C.L.), exceed the present theoretical estimates of the decays half-lives. For $^{189}$Os and $^{192}$Os also decays to the ground states of the daughter nuclei were searched for due to the instability of the daughter nuclides relative to $β$ decay.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
