DECAY OF Tm$sup 17$$sup 3$
DECAY OF Tm$sup 17$$sup 3$
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Tm 的衰变$sup 17$$sup 3$
DOI：
10.1103/physrev.132.355
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发表时间：
1963
期刊：
影响因子：
--
通讯作者：
J. Starner
中科院分区：
文献类型：
--
作者：
C. Orth;M. E. Bunker;J. Starner
通过Er/sup 170/(α，p)TM/sup 173/、Yb/sup 173/(n，p)TM/sup 173/和Yb/sup 174/(γ，p)TM/sup 173/与同位素富集靶的交叉轰击证实了Tm/sup 173/的质量分配，并用β-射线和伽马射线闪烁能谱研究了它的衰变。Tm/sup 173/的半衰期为8.24正负0.08小时，观测到三条能量(和相对强度)分别为66(0.01)、399(1.0)和465(0.09)keV的伽马射线。对β射线能谱的分析表明，存在两个主要的群，其终点能量为1.32正负0.03 Mev(2%)和0.89正负0.04 Mev(98%)。伽玛符合测量和伽马射线强度数据表明，0.89 Mev的β射线群由能量相差66keV的两个分量组成。Tm/sup 173/的衰变方案涉及399 keV和465keV的Yb/sup 173/的激发能级。399keV能级是一种半衰期为3.5正负0.3微秒的同质异能态，它被纯的E2跃迁所抑制，与单粒子估计相比，E2跃迁受到大约1.6×10/sup 3/的更大因子的阻碍。这种阻碍归因于对形变原子核的渐近选择规则的破坏。(Auth)(更少)
The mass assignment of Tm/sup 173/ was confirmed by cross bombardments involving the reactions Er/sup 170/( alpha ,p)Tm/sup 173/, Yb/sup 173/(n,p)Tm/sup 173/, and Yb/sup 174/( gamma ,p)Tm/sup 173/ with isotopically enriched targets, and its decay was studied by BETA -ray and gamma -ray scintillation spectrometry. The half life of Tm/sup 173/ is 8.24 plus or minus 0.08 h. Three gamma rays, with energies (and relative intensities) of 66 (0.01), 399 (1.0), and 465 (0.09) kev, were observed. Analysis of the BETA -ray spectrum indicates the presence of two major groups with end-point energies of 1.32 plus or minus 0.03 Mev (2%) and 0.89 plus or minus 0.04 Mev (98%). Gammagamma coincidence measurements and the gamma -ray intensity data show that the 0.89-Mev BETA -ray group is composed of two components which differ in energy by 66 kev. The proposed decay scheme for Tm/sup 173/ involves excited levels in Yb/sup 173/ at 399 and 465 kev. The 399-kev level is an isomeric state with a 3.5 plus or minus 0.3 mu sec half life, and it de-excites by a pure E2 transition which is hindered by a more » factor of approximately 1.6 x 10/sup 3/ compared to the single- particle estimate. This hindrance is attributed to violation of the asymptotic selection rules for deformed nuclei. (auth) « less