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Dependence of Vacuum Electrical Breakdown Field and Field Enhancement Factor on the Number of Apertures Drilled in Small Electrodes
Author(s) -
ISHIDA RYO,
YAMANO YASUSHI,
KOBAYASHI SHINICHI,
KOJIMA ATSUSHI,
HANADA MASAYA,
SAITO YOSHIO
Publication year - 2016
Publication title -
electrical engineering in japan
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.136
H-Index - 28
eISSN - 1520-6416
pISSN - 0424-7760
DOI - 10.1002/eej.22842
Subject(s) - electrode , field (mathematics) , materials science , field electron emission , dielectric , current (fluid) , electric field , source field , acceleration , optoelectronics , optics , electrical engineering , physics , near and far field , electron , engineering , mathematics , classical mechanics , quantum mechanics , pure mathematics
SUMMARY Dark current based on field emission current is considered to be a factor causing the vacuum electrical breakdown between multiaperture acceleration grids in the JT‐60 negative ion source. In this paper, we focus on field enhancement factor, which is a key parameter of field emission from the electrode. Vacuum breakdown testing for small‐sized electrodes simulating the multiaperture acceleration grids of the negative ion source was performed. We found the field enhancement factor and breakdown field for multiaperture electrodes, and we investigated the dependence of each parameter on the number of apertures. The results revealed that an increase in the average field enhancement factor after the end of conditioning resulting from an increase in the number of apertures led to a decrease in the dielectric strength of the multiaperture electrodes.