Charge transfer cross sections of low-energy highly charged ions with N(sub 2)

Abstract

To study the charge transfer processes of the low-energy highly charged ion and atom (or molecule) collisions, the charge transfer cross sections of highly charged ions were measured. Low-energy highly charged ions from the 14.5 GHz Caprice ion source were energy-analyzed and focused on the gas cell. The cell length was 5 cm. The entrance and exit apertures of the gas cell were 1 and 2 mm, respectively. After the collisions, the ion charge states were analyzed by an electrostatic analyzer and a position sensitive detector. In this article, the total single electron capture cross section of highly charged ions in the collisions with N(sub 2) molecules were reported. The Ar(3,7+), O(3,6+), and N(3+) ions in the energy range of 2 - 10,000 eV/u were used. In this energy range, the energy dependence of the charge transfer cross section is small. This type energy dependence can be explained by a simple model called the absorbing sphere model. The energy dependence of the present results, except for N(3+) ions, was in good agreement with this model made for the single electron capture processes.

低エネルギー多価イオンと原子(または分子)の衝突での荷電輸送過程を研究するため、多価イオンの荷電輸送断面積を測定した。14.5GHzのCapriceイオン源からの低エネルギー多価イオンをエネルギー解析し、気体セルに焦点をあわせた。セルの長さは5cmである。気体セルの入口と出口の口径はそれぞれ1mmと2mmである。衝突後イオンの荷電状態を静電解析装置と位置有感検出器で解析した。ここでは、N(sub 2)分子との衝突での多価イオンの単電子捕獲全断面積を報告する。2-10,000eV/uのエネルギー範囲のAr(3,7+)イオン、O(3,6+)イオン、N(3+)イオンを使用した。このエネルギー範囲では荷電輸送断面積のエネルギー依存性は非常に小さい。この型のエネルギー依存性は吸収球模型と呼ばれる簡単な模型で説明できる。今回の結果のエネルギー依存性はN(3+)イオンを除けば、単電子捕獲過程のこの模型とよく一致している。