Measurement of fission time scale and excitation energy at scission for 25MeV/u Ar-40+Bi-209 fission reaction

	Measurement of fission time scale and excitation energy at scission for 25MeV/u Ar-40+Bi-209 fission reaction
	Zheng, JW ; Wu, EJ ; Zhang, C ; Xiao, ZG ; Wang, SF ; Yin, SZ ; Jin, GM ; Tan, JL ; Jin, WY ; Song, MT
刊名	HIGH ENERGY PHYSICS AND NUCLEAR PHYSICS-CHINESE EDITION
	1999-10-01
卷号	23 页码:946-953
关键词	scission point fission time scale excitation energy
ISSN号	0254-3052
英文摘要	Alpha particles detected in coincidence with,two fission fragments in the reaction of 25MeV/u Ar-40 + Bi-209 have been measured-at the backwards angles of 145 degrees and 95 degrees, respectively. The spectra at each angle are:incremented in two different intervals of linear momentum transfer (LMT). These two intervals of LMT correspond to:two considesably diffesent initial excitation energies, [E*] = 472 and 595MeV, in the primordial hot nuclei formed in the reaction. The moving source analysis of the spectra has been used to extract the prescission-and postscission alpha particle multiplicities, as well as other relevant qualities: such as the temperatures of the target-like residues and fission fragments. The excitation energies at scission, deduced from the postscission alpha pasticle multiplicity are about ,166 and 179 MeV in the two LMT intervals, respectively. Compared with the considesable difference of initial excitation energies, the near equality shows that the excitation energy at scission are not explicitly dependant on the initial excited state of the fission nuclei. The fission time scale of hot nuclei with excitation energy of 470-600MeV, deduced from prescission multiplicity, is about 4 x 10(-21) sec, which indicates that the so-called fast fission dominates in the fission channel of hot nuclei in this excitation energy range.
WOS关键词	HOT NUCLEI
WOS研究方向	Physics
语种	英语
出版者	SCIENCE PRESS
WOS记录号	WOS:000085343300002
内容类型	期刊论文
源URL	[http://119.78.100.186/handle/113462/36115]
专题	中国科学院近代物理研究所
通讯作者	Zheng, JW
作者单位	1.Chinese Acad Sci, Inst Modern Phys, Lanzhou 730000, Peoples R China 2.Beijing Univ, Dept Tech Phys, Beijing 100871, Peoples R China
推荐引用方式 GB/T 7714	Zheng, JW,Wu, EJ,Zhang, C,et al. Measurement of fission time scale and excitation energy at scission for 25MeV/u Ar-40+Bi-209 fission reaction[J]. HIGH ENERGY PHYSICS AND NUCLEAR PHYSICS-CHINESE EDITION,1999,23:946-953.
APA	Zheng, JW.,Wu, EJ.,Zhang, C.,Xiao, ZG.,Wang, SF.,...&Qian, X.(1999).Measurement of fission time scale and excitation energy at scission for 25MeV/u Ar-40+Bi-209 fission reaction.HIGH ENERGY PHYSICS AND NUCLEAR PHYSICS-CHINESE EDITION,23,946-953.
MLA	Zheng, JW,et al."Measurement of fission time scale and excitation energy at scission for 25MeV/u Ar-40+Bi-209 fission reaction".HIGH ENERGY PHYSICS AND NUCLEAR PHYSICS-CHINESE EDITION 23(1999):946-953.