CHARGE STATES AND CHARGE-CHANGING CROSS-SECTIONS OF FAST HEAVY-IONS PENETRATING THROUGH GASEOUS AND SOLID MEDIA
CHARGE STATES AND CHARGE-CHANGING CROSS-SECTIONS OF FAST HEAVY-IONS PENETRATING THROUGH GASEOUS AND SOLID MEDIA
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DOI：
10.1103/revmodphys.44.465
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发表时间：
1972-01-01
影响因子：
44.1
通讯作者：
BETZ, HD
中科院分区：
文献类型：
--
作者：
BETZ, HD
本文综述了包括铀在内的重离子以v0 < v<Zv 0（v0 = e2 π = 2.188× 108 cm/sec）的速度穿透气体和固体靶的电荷态和电荷变化截面的实验和理论情况。特别强调原子序数在16≤ Z≤ 92范围内的离子。出版的文献涵盖到1971年8月。概述了一般的物理和数学关系，它描述了重离子束通过物质的电荷态的组成。总结了最近的实验技术和数据分析方法。大量的实验结果重离子平衡电荷态分布，平均平衡电荷态，和横截面的捕获和损失的一个或多个电子在单次遇到目标原子，并严格审查。这些数据延伸到像铀一样重的离子和能量高达400 MeV。系统的趋势进行了强调和概括进行了讨论，允许插值和在一定程度上外推的数据尚未进行实验研究的范围。注意的是多电子损失的横截面是相对较大的，但这是知之甚少。根据最近的实验结果，我们讨论了剩余离子激发对电荷变化碰撞的影响。它表明，重离子的平均平衡电荷可以近似利用两个理论概念，起源于玻尔和兰姆的工作，和半经验的关系，这是基于观察到的数据的重复性。对与密度效应相关的现象的最新解释，即随着目标密度增加而观察到的射弹电离的增加，进行了仔细审查，并探索了波尔和林哈德对理论的改进。
This review surveys the experimental and theoretical situation concerning charge states and charge-changing cross sections of heavy ions up to and including uranium, which penetrate through gaseous and solid targets with velocities primarily in the range v 0< v< Z v 0 (v 0= e 2 ℏ= 2.188× 10 8 cm/sec). Particular emphasis is given to ions with atomic numbers in the range 16≤ Z≤ 92. The published literature is covered through August 1971. General physical and mathematical relations are outlined which describe the composition of charge states in a heavy-ion beam which passes through matter. Recent experimental techniques and methods of data analysis are summarized. Extensive experimental results on heavy-ion equilibrium charge state distributions, average equilibrium charge states, and cross sections for capture and loss of one or more electrons in single encounters with target atoms are presented and critically examined. The data extend to ions as heavy as uranium and energies up to∼ 400 MeV. Systematic trends are emphasized and generalizations are discussed which allow interpolations and to some extent extrapolations of the data to be made to ranges which have not been investigated experimentally. Attention is given to the cross sections for multiple-electron loss which are relatively large but which are poorly understood. We deal with effects of residual ion excitation on charge-changing collisions in the light of recent experimental results. It is shown that the average equilibrium charge of heavy ions can be approximated by utilizing both theoretical concepts which originate from the work of Bohr and Lamb, and semiempirical relations which are based on observed regularities of the data. Recent interpretations of phenomena associated with density effects, ie, with the increase of projectile ionization which is observed for increasing target densities, are scrutinized and refinements of the theory by Bohr and Lindhard are explored.