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Needle Growth Induced by Corona Discharge
Author(s) -
Okuyama F.
Publication year - 1984
Publication title -
beiträge aus der plasmaphysik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.531
H-Index - 47
eISSN - 1521-3986
pISSN - 0005-8025
DOI - 10.1002/ctpp.19840240608
Subject(s) - corona discharge , cathode , brush discharge , torr , materials science , corona (planetary geology) , electron , field electron emission , plasma , electric discharge in gases , atomic physics , electrode , chemistry , electrical engineering , physics , nuclear physics , venus , thermodynamics , engineering , astrobiology
It is shown that the growth of a dense array of chromium microneedles is induced on a field cathode tip interacting with a negative corona discharge in ambient Cr(CO) 6 of 1 – 5 × 10 −2 Torr. The growth begins with the initiation of a corona discharge surrounding the tip, and it proceeds as long as the discharge is sustained. The needles emit field electrons during the growth, thereby sustaining the discharge, while the discharge lengthens the needles by supplying metallic particles to their tips. The morphological structure of the needles is strongly affected by an external magnetic field, leading us to hypothesize that the needle grow axially as the electron avalanches, originating at the cathode tip, propagate outward from tip.