重离子耗散反应激发函数中的截面涨落

Fluctuation in the Dissipative Heavy Ion Collisions of ^(19)F+^(93)Nb

完成了两次独立的 1 9F + 93Nb激发函数测量;束流 1 9F8+的入射能量 1 0 0～ 1 0 8MeV,能量步长 2 5 0keV。两次测量的宏观条件完全相同,实验结果有近 1/3的相同能量点所对应的反应截面及其涨落不重复。在双核系统中引入宇称和自旋的退相干描述能量自关联函数中准周期性的衰减结构;

Two independent measurements of excitation functions in dissipative collisions of 19 F+ 93 Nb have been carried out at incident energies from 100 MeV to 108 MeV in steps of 250 keV. The experimental conditions were kept to be identical in both measurements. The data indicate non reproducibility of the non self averaging oscillating cross sections. The quasi periodic structure in the energy autocorrelation functions is described by means of the concept of parity and spin decoherence in the intermediate dinuclear system. The non reproducibility of the cross sections is interpreted by the extreme sensitivity of initial condition in the quantum chaotic motion.