重离子束在热靶中的电子阻止本领与有效电荷数

采用线性介电响应理论,研究了重离子束在热靶中的有效电荷数和电子阻止本领。为了考虑入射离子的束缚电荷分布,我们将Brandt-Kitagawa的有效电荷理论推广到热靶。在低速和高速情况下,分别得到了有效电荷数和电子阻止本领的解析表示式。数值结果表明,对于低速离子,有效电荷数随电子气的温度增加而增加;在一定的温度范围内,低速离子的阻止本领与冷靶相比有明显增加。对于高速离子,我们的理论结果与实验值符合得较好。 关键词：

ELECTRONIC STOPPING POWER AND EFFECTIVE CHARGE OF HEAVY ION-BEAM IN HOT TARGETS

Using linear-response dielectric theory, we have investigated the electronic stopping power and effective charge of heavy ionbeams in hot targets. For considering the charge distribution of the electrons bound to the projectile, the theoretical model of Brandt-Kitagawa is generali-zed to the situation of hot target. In the case of low and high velocities, the analytical expres-sions of the electronic stopping power and the effective charge are obtained, respectively. For low-velocity ion, it has been shown that the values of the effective charge are increased as the values of the electron gas temperature are increased. In certain temperarure range the values of the stopping power in the hot target are increased comparing with that in the cold target. For high-velocity ions in the hydrogen plasma, the theoretical values of the stopping power obtained in present work agree very well with experimental data.