几百兆电子伏特/核子能区原子核诱发乳胶核反应靶核蒸发碎片前后发射研究（英文）  

Forward-backward Emission of Target Evaporated Fragments in Nucleus-emulsion Collisions at a few Hundred MeV/nucleon

作　　者：杨瑞霞[1] 徐明明[1] 马田丽 张智[1] 石瑞[1] 张东海[1] 

机构地区：[1]山西师范大学现代物理研究所,山西临汾041004

出　　处：《原子核物理评论》2016年第3期274-280,共7页Nuclear Physics Review

基　　金：National Natural Science Foundation of China(11075100);Natural Science Foundation of Shanxi Province(2011011001-2);Shanxi Provincial Foundation for Returned Overseas Chinese Scholars(2011-58)~~

摘　　要：对150 AMeV^4He-AgBr,290 AMeV^(12)C-AgBr,400 AMeV ^(12)C-AgBr,400 AMeV ^(20)Ne-AgBr及500 AMeV ^(56)Fe-AgBr作用靶核蒸发碎片在反应前后半球内的多重数分布、多重数矩、标度方差、熵及约化熵分别进行了分析。实验结果表明,靶核蒸发碎片在前后半球内的多重数分布可以用高斯分布来描述。在前后半球内的多重数分布矩分别随秩数的增加而增加,且前后半球内多重数分布二阶矩与反应类型及束流能量无关。对于所有研究的核反应,其标度方差(一个直接描述多重数涨落的变量)值接近于1,表明在前后半球内靶核蒸发的发射存在较弱的关联。在前后半球内靶核蒸发碎片发射过程中的熵及约化熵在实验误差范围内与反应系统无关。The multiplicity distribution, multiplicity moment, scaled variance, entropy and reduced entropy of target evaporated fragments emitted in forward and backward hemispheres in 150 AMeV ^4He-Ag Br, ^290AMeV ^12C-AgBr, 400 AMeV ^12C-AgBr, 400AMeV ^20Ne-Ag Br and 500 AMe V56 FeAg Br interactions are investigated. It is found that the multiplicity distribution of target evaporated fragments emitted in both forward and backward hemispheres can be fitted by a Gaussian distribution.The multiplicity moments of target evaporated particles emitted in the forward and backward hemispheres increase with the order of the moment q, and the second-order multiplicity moment is energy independent over the entire energy range for all the interactions in the forward and backward hemisphere. The scaled variance, a direct measure of multiplicity fluctuations, is close to one for all the interactions, which indicate a weak correlation among the target evaporated fragments. The entropy of target evaporated fragments emitted in forward and backward hemispheres are the same respectively for all of the interactions, within experimental errors.

关 键 词：重离子碰撞 靶核碎裂 多重数 原子核乳胶 

分 类 号：O571.6[理学—粒子物理与原子核物理]