实验检测自然木的放射性衰变中的α粒子
Pierre de Marcillac1, Noël Coron, Gérard Dambier
1Institut d'Astrophysique Spatiale, CNRS & Université Paris Sud, UMR 8617, Bât. 121, 91405 Orsay Cedex, France. pierre.demarcillac@ias.u-psud.fr
Nature
|April 25, 2003
概括
曾经被认为是稳定的-209 (209Bi) 经历了α-衰变. 研究人员使用敏感的冷探测器成功检测到这种罕见事件,证实了其转移稳定性并测量了其极长的半衰期.
科学领域:
- 核物理 核物理 核物理
- 粒子物理学 粒子物理学
- 天体物理学 天体物理学
背景情况:
- 同位素-209 (209Bi) 是天然存在的唯一同位素.
- 209Bi被认为是最重的稳定同位素,但它实际上是转移稳定的.
- 它的α-衰变的概率极低,并产生低能量的α粒子,使检测具有挑战性.
研究的目的:
- 为了明确检测比斯-209 (209Bi) 的α-衰变.
- 测量209Biα-衰变的能量释放和半衰期.
- 为了验证使用闪的博洛米特来检测罕见的核事件.
主要方法:
- 使用了在低温温度 (20mK) 操作的闪波计.
- 采用了木生殖探测器,以提高灵敏度和检测效率.
- 克服了使用核乳液的先前实验的局限性.
主要成果:
- 成功检测到209Bi.Bi的α衰变.
- 测量的能量释放量为3,137 +/- 1 (统计) +/- 2 (系统) keV.
- 确定了 (1.9 +/- 0.2) x 10 ^ 19 年的半衰期,与理论预测一致.
结论:
- 通过直接观察其α-衰变,证实了209Bi的转移稳定性.
- 证明了冷闪波罗米特用于研究罕见核衰变的有效性.
- 提供了对209Bi衰变特性的精确测量,这与核物理学和天体物理学有关.
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