Study of the effects of roughness, ultraviolet radiation, multipactoring and magnetic field on vacuum breakdown

Breakdowns in vaccuum and the factors a ffecting them have been studied for more than a hundred years, with applications ranging from high voltage isolation to space propulsion. In current thermonuclear fusion projects, one of the methods of heating the plasma is through ion cyclotron radiofrequency heating. ICRF antennas are used to this end, while the voltage and hence the power possible to deliver through these antennas is limited because of breakdowns. The focus of this research has been to study some of the factors suspected to a ffect these breakdowns, namely, the macroscopic surface roughness and ultraviolet radiation, with the ultimate purpose of raising the breakdown threshold of ICRF antennas in order to deliver more power to thermonuclear fusion plasmas. Macroscopic surface roughness did not signify any regular prediction of breakdown threshold in copper and aluminum electrodes subjected to DC voltage. Though the presence of ultraviolet radiation lowered the breakdown threshold on average, the difference in the mean values was smaller than the uncertainty in measurement, making the results inconclusive until further studies are performed.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Nuclear Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2013

Author dc:creator

• Aghazarian, Maro

Contributors dc:contributor

• Ruzic, David N.

• vacuum breakdowns
• Ion Cyclotron Range of Frequencies (ICRF) antennas
• breakdown
• macroroughness
• high voltage breakdown
• electrical breakdown
• surface roughness
• effects of UV on breakdown
• vacuum breakdown
• ICRF antenna breakdown

Statement dc:rights

• Copyright 2013 Maro Aghazarian

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/45506

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/45506