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Electrode phenomena and current distribution in a radial multichannel pseudospark switch

 

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Journal of applied physics 84 (1998), Nr.8, S.4180-4184 : Ill., Lit.
ISSN: 0021-8979
ISSN: 1089-7550
Englisch
Zeitschriftenaufsatz
Fraunhofer ILT ()
cathode spot; erosion; macrospot; microscopic structure; multichannel pseudospark; pseudospark switch; scanning electron microscopy

Abstract
The microscopic structure and the spatial distribution of the cathode spots in a radial multichannel pseudospark switch have been investigated by means of scanning electron microscopy. Current pulses of about 15 my s duration and peak amplitudes up to 340 kA have been applied. When using stainless steel and copper as electrode material cathode spots of type I and type II are observed. These cathode spots appear in groups (macrospots) with a diameter of several 100 mu m. Assuming that the lifetime of the macrospots corresponds to the half period time of the current pulse the distribution of the cathode spots within the macrospots can be explained by a retrograde motion of the spots with a velocity of several 100 m/s in the self-magnetic field of the discharge current. Furthermore, the spatial distribution of the cathode spots within the macrospots can be interpreted by assuming a splitting and a repulsion of the cathode spots. The electrode phenomena show that the discharge current is d istributed over a large area which is prerequisite for low erosion and long lifetime operation of the switch.

: http://publica.fraunhofer.de/dokumente/PX-11636.html