Physical processes in a super-tip gas field ion source
Physical processes in a super-tip gas field ion source
复制标题
超尖端气体场离子源中的物理过程
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
A. Knoblauch
中科院分区：
文献类型：
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作者：
S. Kalbitzer;A. Knoblauch
从W和Ir超尖端的气体场离子源中可以引出强流的氢和稀有气体离子束。本文研究了温度和电场对Ar、Ne和He发射电流的影响。特别是Ar/W系统已经获得了大多数实验细节。最佳操作温度接近每种气体的冷凝点。物理吸附和解吸的影响，修改局部变化的极化力，产生三个温度制度。发射电流的控制在热激活扩散和解吸过程之间的复杂竞争。通过假设局部动态平衡场增强动力学供应从气相中，发射极温度特性的理论描述已经实现。
Intense ion beams of hydrogen and rare gases, can be extracted from W and Ir super-tips of a gas field ion source. In this study, the influence of temperature and electrical field on the emitted currents of Ar, Ne and He has been investigated. In particular, the system Ar/W has yielded most experimental details. Optimum operation temperatures are near to the condensation point of each gas species. Physical adsorption and desorption effects, modified by locally varying polarisation forces, give rise to three temperature regimes. The emitted current is controlled in complex competition between thermally activated diffusion and desorption processes. By assuming local dynamic equilibria with field-enhanced kinetic supply from the gas phase, a theoretical description of the emitter-temperature characteristics has been achieved.