Energy distribution and formation mechanism of fast atoms in a fast atom beam
Energy distribution and formation mechanism of fast atoms in a fast atom beam
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快原子束中快原子的能量分布及形成机制
DOI：
10.1063/1.352173
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发表时间：
1992
影响因子：
3.2
通讯作者：
H. Kuwano
中科院分区：
文献类型：
--
作者：
F. Shimokawa;H. Kuwano
使用与电离室耦合的减速场能量分析仪测量通过修改 McIlraith 型快原子束 (FAB) 源产生的快原子的能量分布。能量分布主要取决于FAB源的气体压力。当气压较低时，主要能量分布峰值与放电电压重合，因此离子在变成快速原子时保留了加速能量。当气体压力较高时，峰值能量出现在放电电压的25%左右，并且具有更宽的频谱。能量分布几乎完全独立于放电电压、放电电流和源阳极的几何形状。快原子主要是由源内部的共振电荷转移碰撞产生的。这些碰撞在 FAB 形成的电子-离子重组中占主导地位。
The energy distribution of fast atoms produced by modifying a McIlraith‐type fast atom beam (FAB) source is measured using a retarding‐field energy analyzer coupled with an ionization chamber. The energy distribution mainly depends on the gas pressure of the FAB source. When the gas pressure is low, the main energy distribution peak coincides with the discharge voltage, so the acceleration energy of the ions is retained when they become fast atoms. When the gas pressure is high, the peak energy appears at about 25% of the discharge voltage and has a broader spectrum. The energy distribution is almost completely independent of the discharge voltage, discharge current, and the geometry of the source anode. The fast atoms are mainly produced by resonant charge‐transfer collisions inside the source. These collisions are dominant over electron‐ion recombinations for FAB formation.