Ion Desorption from Bulk Cesium Chloride at Moderate Temperature ( 500°C) under Electric Field

摘要

Desorption of positive ions as well as neutrals from bulk cesium chloride has been investigated in the moderate temperature ( 500°C), which is lower than its melting point (645°C). At this moderate temperature range, neutral Cs was slightly desorbed, but desorption of Cs~(+) ions was not observed. On the other hand, when the positive potential was applied to the sample, Cs~(+) ions were desorbed with abnormally high intensity. The ratio of the desorbed ions to neutrals (I _(Cs+) /I _(Cs)) showed a maximum at around 415°C. Based on the analysis using the Saha-Langmuir model, the observed high Cs~(+) desorption yield under electric field was interpreted by the changes in the surface work function caused by the phase transition of CsCl. The abnormally high Cs~(+) desorption yield at such low temperature under electric field would be applied to various fields such as ion production in accelerator and separation of cesium from complex systems through dry process.