First Direct Measurement of Isotopic Fission-Fragment Yields of ^{239}U.
First Direct Measurement of Isotopic Fission-Fragment Yields of ^{239}U.
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^{239}U 的同位素裂变碎片产量的首次直接测量。
DOI：
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发表时间：
2019
影响因子：
8.6
通讯作者：
I. Tsekhanovich
中科院分区：
文献类型：
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作者：
D. Ramos;M. Caamano;A. Lemasson;M. Rejmund;L. Audouin;H. Alvarez;J. Frankland;B. Fernández;E. Galiana;J. Piot;D. Ackermann;S. Biswas;E. Clément;D. Durand;F. Farget;M. Frégeau;D. Galaviz;A. Heinz;A. Henriques;B. Jacquot;B. Jurado;Y. H. Kim;P. Morfouace;D. Ralet;T. Roger;C. Schmitt;P. Teubig;I. Tsekhanovich
首次对^{239}U同位素裂变碎片产量进行了直接、完整的测量。 ^{239}U 裂变系统是在 ^{238}U 束和 ^{9}Be 靶材之间在库仑势垒能量下进行单中子转移反应时产生的，平均激发能量为 8.3 MeV。使用 GANIL 设施的 VAMOS++ 光谱仪对裂变碎片进行了检测和同位素鉴定。该测量使我们能够直接评估快中子激发能量下的裂变模型，这与下一代核反应堆相关。目前的数据与模型计算一致，不支持最近报道的^{239}U裂变碎片产率的异常，并且它们证实了在激发能量超过裂变势垒几兆电子伏时，Sn区域中球壳效应的持续存在。
A direct and complete measurement of isotopic fission-fragment yields of ^{239}U has been performed for the first time. The ^{239}U fissioning system was produced with an average excitation energy of 8.3 MeV in one-neutron transfer reactions between a ^{238}U beam and a ^{9}Be target at Coulomb barrier energies. The fission fragments were detected and isotopically identified using the VAMOS++ spectrometer at the GANIL facility. The measurement allows us to directly evaluate the fission models at excitation energies of fast neutrons, which are relevant for next-generation nuclear reactors. The present data, in agreement with model calculations, do not support the recently reported anomaly in the fission-fragment yields of ^{239}U, and they confirm the persistence of spherical shell effects in the Sn region at excitation energies exceeding the fission barrier by a few mega-electron volts.