用充Kr(CH_4)的屏栅电离室测量^(64)Zn(n,α) ^(61)Ni反应截面和角分布

Measurement of cross section and angular distribution for ^(64)Zn(n,α) ^(61)Ni by using gridded ionization chamber of Kr( CH_4 ) gas

用屏栅电离室重点对 5 .0、5 .7、6 .5 Me V中子 64Zn(n,α) 61Ni反应角分布和微分截面进行了测量 ,同时兼测 10 B(n,α) 7Li,利用氚气体通过 D(d,n) 3 He反应来刻度 ,工作气体采用 Kr+ 4 .71% CH4,由于采用了 Kr+ 4 .71% CH4为工作气体 ,消除了 16O的 (n,α)干扰。首次很清晰地得到了多组激发态的64Zn(n,α) 61Ni的事件双维谱以及激发态的 10 B(n,α) 7L i事件双维谱 ,测量结果表明 64Zn(n,α) 61Ni的角分布在 5 .7Me V时很接近 90°对称 ,而到 6 .5 Me V时明显后倾。

By using a gridded ionization chamber, the angular distribution and total cross section for 64 Zn(n, α) 61 Ni reaction were measured at 5.0,5,7 and 6.5MeV, and included 10 B(n, α) 7Li measurement. The neutrons were produced through D(d,n) 3He reaction, working gas was Kr+4.71% CH 4. Because using Kr+4.71% CH 4 as working gas, there is no interference from 16 O(n, α), we got two dimensions events spectrums of the many excited states groups of 64 Zn(n, α) 61 Ni and high excited state of 10 B(n, α) 7Li clearly at first in the world, the result of measurement show that the distribution of 64 Zn(n, α) 61 Ni was nearly 90° symmetric at 5.7MeV, and obviously backward peaked in the center of mass reference system.