Decay properties of {sup 265}Sg(Z=106) and {sup 266}Sg(Z=106)
Decay properties of {sup 265}Sg(Z=106) and {sup 266}Sg(Z=106)
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{sup 265}Sg(Z=106) 和 {sup 266}Sg(Z=106) 的衰变特性
DOI：
10.1103/physrevc.57.1648
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发表时间：
1998
影响因子：
3.1
通讯作者：
S. Taut
中科院分区：
文献类型：
--
作者：
A. Tuerler;R. Dressler;B. Eichler;H. Gaeggeler;D. Jost;M. Schaedel;W. Brüchle;K. Gregorich;N. Trautmann;S. Taut
目前已知最富中子的106号元素(seborgium，Sg)、{sup 265}Sg和{sup 266}Sg是在束流能量为121 MeV和123 MeV的聚变反应{sup 22}Ne+{sup 248}cm中产生的。使用在线气体化学仪OLGA，在几秒钟内实现了Sg的连续分离。最终产物用{α}粒子和自发裂变(SF)光谱分析。通过观察时间相关的{α}-{α}-({α})和{α}-SF衰变链，确定了{sup 265}Sg和{sup 266}Sg。共鉴定出13条{sup 265}Sg的相关衰减链(估计有2.8个随机关联)和3条{sup 266}Sg的衰减链(0.6个随机关联)。推导出的衰变性质为T{sub1/2}=7.4{sub1/2}=7.4{sub{-}2.7}{sup+3.3}S(68{%}C.I.)对于{sup 265}sg，E{sub1/2}=8.69 MeV(8{%})、8.76 MeV(23{%})、8.84 MeV(46{%})和8.94 MeV(23{%})；T{sub1/2}=21{sub{-12}{sup+20}S(68{%}C.I.)对于{sup 266}Sg，E{Sub{α}}=8.52 MeV(33{%})和8.77 MeV(66{%})。探测器的分辨率在50~100keV(半高全宽)之间。对于{sup 265}Sg和{sup 266}Sg，分别建立了{le}35{%}和{le}82{%}的SF上限。利用Sg和Sg的半衰期的误差下限，得到部分Sf半衰期的下限为T{sub1/2}{sup sf}(sup 265}sg){ge}13 S和T{sub1/2}{sup SF}(sup 266}sg){ge}11 S。相应地，偏α衰变的半衰期介于T{sub1/2}{sup{α}}(sup 265}Sg)=4.7{endash}16.5 S(68%C.I.)之间。和T{sub1/2}{sup{α}}({sup 266}sg)=9{endash}228 S(68%C.I.)，利用{sup 265}sg和{sup 266}sg的半衰期的上下限。{sup 266}Sg的部分SF半衰期下限与理论预测符合得很好。估算了{sup 265}Sg和{sup 266}Sg中{α}-衰变分支的产生截面分别约为240PB和25PB。{版权所有}{ital1998}{italthe American Physitive Society}
The presently known most neutron-rich isotopes of element 106 (seaborgium, Sg), {sup 265}Sg and {sup 266}Sg, were produced in the fusion reaction {sup 22}Ne+{sup 248}Cm at beam energies of 121 and 123 MeV. Using the On-Line Gas chemistry Apparatus OLGA, a continuous separation of Sg was achieved within a few seconds. Final products were assayed by {alpha}-particle and spontaneous fission (SF) spectrometry. {sup 265}Sg and {sup 266}Sg were identified by observing time correlated {alpha}-{alpha}-({alpha}) and {alpha}-SF decay chains. A total of 13 correlated decay chains of {sup 265}Sg (with an estimated number of 2.8 random correlations) and 3 decay chains of {sup 266}Sg (0.6 random correlations) were identified. Deduced decay properties were T{sub 1/2}=7.4{sub {minus}2.7}{sup +3.3} s (68{percent} c.i.) and E{sub {alpha}}=8.69 MeV (8{percent}), 8.76 MeV (23{percent}), 8.84 MeV (46{percent}), and 8.94 MeV (23{percent}) for {sup 265}Sg; and T{sub 1/2}=21{sub {minus}12}{sup +20} s (68{percent} c.i.) and E{sub {alpha}}=8.52 MeV (33{percent}) and 8.77 MeV (66{percent}) for {sup 266}Sg. The resolution of the detectors was between 50{endash}100 keV (full width at half maximum). Upper limits for SF of {le}35{percent} and {le}82{percent} were established for {sup 265}Sg and {sup 266}Sg, respectively. The upper limits for SF are given with a 16{percent} error probability.more » Using the lower error limits of the half-lives of {sup 265}Sg and {sup 266}Sg, the resulting lower limits for the partial SF half-lives are T{sub 1/2}{sup SF}({sup 265}Sg){ge}13 s and T{sub 1/2}{sup SF}({sup 266}Sg){ge}11 s. Correspondingly, the partial {alpha}-decay half-lives are between T{sub 1/2}{sup {alpha}}({sup 265}Sg)=4.7{endash}16.5 s (68{percent} c.i.) and T{sub 1/2}{sup {alpha}}({sup 266}Sg)=9{endash}228 s (68{percent} c.i.), using the upper and lower error limits of the half-lives of {sup 265}Sg and {sup 266}Sg. The lower limit on the partial SF half-life of {sup 266}Sg is in good agreement with theoretical predictions. Production cross sections of about 240 pb and 25 pb for the {alpha}-decay branch in {sup 265}Sg and {sup 266}Sg were estimated, respectively. {copyright} {ital 1998} {ital The American Physical Society}« less