測(cè)量熱陰極次級(jí)發(fā)射特性的掃描電子探針?lè)?/h2>
A SCANNING LOW ENERGY ELECTRON PROBE FOR MEASURING THE SECONDARY EMISSION OF THERMIONIC CATHODES
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摘要: 本文介紹了一種適用于量測(cè)熱陰極次級(jí)發(fā)射特性的掃描電子探針?lè)?原電子探束束斑直徑為50100m,束流小于10-7A,原電子能量不大于3kV。該裝置能定點(diǎn)測(cè)量熱陰極表面上感興趣點(diǎn)的次級(jí)發(fā)射系數(shù)與原電子能量間的關(guān)系曲線(-Ep);也能以掃描方式在短時(shí)間內(nèi)測(cè)出整個(gè)熱陰極表面的次級(jí)發(fā)射分布,從而求得次級(jí)發(fā)射的定量分布曲線(f-)。該裝置在電視制式的掃描方式工作時(shí),能觀察熱陰極表面的次級(jí)發(fā)射圖象。 對(duì)純鎳樣品的測(cè)量表明:該裝置具有比單槍定點(diǎn)法更多的優(yōu)點(diǎn)和更高的精度。由于該裝置簡(jiǎn)便靈活,便于與熱陰極研究的特殊需要相結(jié)合,因此,可望在熱陰極的研究中發(fā)揮作用。
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Abstract: For this probe, the beam spot diameter of the primary electron beam is 50-100m, the primary beam current is lower than 10-7A, and the energy of the primary electron (Ep) can be varied from 200 eV to 3 keV.By use of this probe, the secondary emission coefficient () versus Eq curve and the secondary emission distribution over the cathode surface can be measured, and the secondary emission image of the cathodes can also be displayed. Finally, the secondary emission of the pure nikel sample and impregnated dispenser cathode are measured. -
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