CNT paste emitters with minimal damage during high temperature vacuum brazing fabricated using fillers having low catalytic activities

摘要

X-ray tubes with an electron source of carbon nanotubes (CNTs) have often been fabricated by vacuum brazing at high temperature, during which CNT emitters have been frequently damaged probably by reacting with other ingredients incorporated into the CNT paste. In particular, some metal or oxide fillers seemed to accelerate the catalytic decomposition of CNTs during high-temperature treatment. In this study, a filler material with a low catalytic activity and good adhesion was selected to replace the conventional fillers of the CNT paste. Upon vacuum heat treatment, the CNT paste containing our new filler showed considerable improvement of field emission properties, compared with the conventional CNT pastes, due to its low catalytic activity.