The focus of this work is the experimental investigation of electron velocity
distribution functions in the plasma of the Texas Helimak experiment. Texas Helimak
has a cylindrical geometry and relatively moderate plasma parameter, which
allow the use of a retarding field analyzer that is located approximately in the middle
of the vacuum vessel. Electron velocity distribution functions were measured
for a variety of different operating conditions and for two gas species, namely argon
and helium. Parameter scans, whereby all parameter except the scan parameter
were kept constant, were done in order to investigate the influence of the scan
parameter on the velocity distribution. It was found, that most electron velocity
distribution functions are not alone Maxwellian. One of the reasons therefore is
electron cyclotron resonance heating, which was used for ionizing and heating the
plasma and what produces a suprathermal tail. It is possible, however, to obtain
effective electron temperatures. These effective electron temperatures range
from about 10 eV , what is similar to the electron bulk temperature, to more than
150 eV. / text
| Identifer | oai:union.ndltd.org:UTEXAS/oai:repositories.lib.utexas.edu:2152/ETD-UT-2012-08-6204 |
| Date | 08 November 2012 |
| Creators | Schmitt, Simon Christian |
| Source Sets | University of Texas |
| Language | English |
| Detected Language | English |
| Type | thesis |
| Format | application/pdf |
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