【摘要】 本文报道了用71.5MeV的¹²C重离子轰打¹⁵⁹Tb、Ag和⁸⁹Y靶,测出了发射α粒子的能谱和角分布,以及发射氘和质子的一些角分布。所测到的α颗子能谱为钟罩形连续谱,其最可几能量接近于库仑位垒。对于¹⁵⁹Tb靶和Ag靶,α粒子角分布在近于或小于擦边角处成峰;而对⁸⁹Y靶,从最小测量角（40°）开始,微分截面随角度增加单调下降。α粒子发射截面均远远大于统计级联蒸发截面值。发射质子与氘的角分布,均随角度增加呈指数下降趋势,它表现出前平衡发射的特征。为了解释α粒子角分布中的各向异性部分,提出了强阻尼粘合转动的概念,它是以不完全熔合反应模型作为基础的。更多还原

【Abstract】 The energy spectra and angular distributions of α-particle emitted from ¹²C-induced reactions with ¹⁵⁹Tb, Ag and ^s9Y targets have been measured. Meanwhile the emitted deutron’s angular distributions with ¹⁵⁹Tb and ⁸⁹Y targets and proton’s with ⁸⁹Y target have been also obtained.The α-energy spectra associated with mentioned reactions have bell-like shape with probable energy near coulomb barrier. However, the main characteristic of the α-angular distribution for ^l59Tb and Ag targets is peaked at or near the grazing angles. For the case of ⁸⁹Y target, α-differential cross-sections monotonically decrease with angles beyond 40°. The angular distributions of protons and deutrons nearly decrease exponentially.The measured α-angular distributions could be divided into two components, one coming from α-evaporation is isotropic, another is anisotropic. The anisotropic component may be explained incomplete-fusion process in which the cross-section can be reproduced by a "Sum-Rule Model" due to J. "Wilezynski.In order to explain the anisotropic component of emitted α-particle, we propose incomplete fusion model with a strong-damped sticking rotation, in which the rotation angles and interaction time of the composite system are also estimated.更多还原