Arc tracks on nanostructured surfaces after microbreakdowns

Studying of initial steps of unipolar arc ignition process is important for reduction of probability of arcing between the plasma and the wall in thermonuclear devices. Tungsten nano-fuzz surface formed by helium plasma irradiation at high fluences and temperatures is a perfect material for arc igni...

Full description

Saved in:
Bibliographic Details
Published in:Journal of physics. Conference series 2016-09, Vol.748 (1), p.12012
Main Authors: Sinelnikov, D, Bulgadaryan, D, Hwangbo, D, Kajita, S, Kolodko, D, Kurnaev, V, Ohno, N
Format: Article
Language:English
Subjects:
Breakdown
Craters
Electric arcs
Helium plasma
Ignition
Low currents
Physics
Thermal conductivity
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Studying of initial steps of unipolar arc ignition process is important for reduction of probability of arcing between the plasma and the wall in thermonuclear devices. Tungsten nano-fuzz surface formed by helium plasma irradiation at high fluences and temperatures is a perfect material for arc ignition. Snowflake-like craters were detected on the fuzzy surfaces after short micro-breakdowns. Such sort of craters have not been observed before on any other metallic surfaces. These specific traces are formed due to unique properties of the fuzz structure. The nano-fuzz could be easily melted and vaporized by micro-breakdown current, due to its porosity and bad thermal conductivity, and formation of low conducting metallic vapour under the cathode spot causes discharge movement to the nearest place. Thus, even low current arc can easily move and leave traces, which could be easily observed by a secondary electron microscope.
ISSN:1742-6588
1742-6596
1742-6596
DOI:10.1088/1742-6596/748/1/012012