【摘要】 基于两体碰撞近似的BEA模型和电子俘获的OBK模型,利用蒙特卡罗的方法计算了0.1～10倍玻尔速度的O⁴⁺离子穿过长度为20 cm的H₂气体靶后的电荷态分布情况。分析结果表明:5×10¹⁴cm^-3是出射离子电荷态升高的临界密度,在此之前,电荷态的变化主要是降低;在此之后,还出现了升高的电荷态。随着靶密度的增加,升高电荷态的比例增大。同一靶密度下,平均出射电荷态随入射离子速度的增大而增加。10 v₀的O⁴⁺离子穿过5×10¹⁸cm^-3的靶后全裸离子的比例可达93%。这为提高加速器出射离子的电荷态提供了重要的理论参考。更多还原

【Abstract】 Based on the model of BEA for direct coulomb ionization and OBK for electron capture,the distribution of charge state for 0.1～10 v₀O⁴⁺ions passing through gaseous target of H₂with length of 20 cm was simulated using the method of Monte Carlo Code.The result indicates that the critical density of charge state increase is about 5×10¹⁴cm^-3.For n_a<5×10¹⁴cm^-3,the inner-shell process is dominated by electron capture,and the performance of charge-changing is mainly the elevation of the charge state.When n_a>5×10¹⁴cm^-3,ionization cross section is larger than that of capture,the charge-changing is mainly dwindled.The proportion of elevated charge state is increased with the increase of target density and incident ion velocity.The proportion of bare ions can reach 98%for 10 v₀O⁴⁺passing through target with density of 5×10¹⁸cm^-3.This provides an important reference for improving the charge state of ions from accelerator.更多还原