同位旋对断前粒子发射的壳结构依赖性

用扩散模型研究了壳对幻数附近的核,即²⁰⁴Pb,²⁰⁸Pb,²¹²Pb和¹²⁸Sn,¹³²Sn,¹³⁶Sn,在裂变过程中蒸发轻粒子多重性的影响.发现壳能够影响粒子发射的同位旋依赖性,并且该影响的大小与复合系统的自旋和激发能有关.计算表明角动量在壳影响同位旋相关的粒子发射中起到了显著的作用,而高激发能弱化了壳的影响.

Dependence of Isospin Effects of Particle Evaporation on the Nuclear Shell Structure

The shell effects on the particle evaporation for those nuclei near magic number,namely, 204 Pb, 208 Pb and 212 Pb as well as 128 Sn, 132 Sn and 136 Sn,are investigated via a diffusion model. Calculations show that shell has an effect on the isospin dependence of particle emission,and that the magnitude of this shell effect is related to the spin and excitation energy of compound systems. It is found that angular momentum plays a significant role in the shell effects on the isospin-dependent particle emission while high excitation energy weakens such shell effects.