A Neutral Beam Probe for the Helimak plasma experiment

dc.contributor.advisorHallock, G. A.
dc.creatorGarcia de Gorordo, Alvaroen
dc.date.accessioned2013-07-15T20:02:08Zen
dc.date.accessioned2017-05-11T22:33:16Z
dc.date.available2017-05-11T22:33:16Z
dc.date.issued2013-05en
dc.date.submittedMay 2013en
dc.date.updated2013-07-15T20:02:08Zen
dc.descriptiontexten
dc.description.abstractA Neutral Beam Probe (NBP) was developed for studying the Texas Helimak plasma experiment. The probe consisted of a beam of neutral sodium atoms that were injected into the magnetized plasma of the Helimak. After some fraction of the atoms underwent electron impact ionization, the resulting ion beam followed a path to an energy analyzer where the change of energy was detected along with the total ion current. The measurement of the change of energy implies a change of potential energy at the point of ionization since all the neutral beam particles enter the plasma with a well determined energy. The total current detected at the energy analyzer also implies a rate of electron impact ionization, which in turn implies an electron density and temperature. The NBP was developed based on the Elmo Bumpy Torus (EBT) Heavy Ion Beam Probe (HIBP), which was operated at Oak Ridge National Labs. In fact, the majority of the equipment that was used in this experiment was taken from that HIBP, and some of it was rebuilt. We generated an estimate of the radial electric field in the Helimak along with an estimate of density changes as a result of biasing experiments. Interestingly, when a bias voltage was applied inside the Helimak, the radial electric field did not change significantly at the sample region, but the electron density did vary. The probe data taken by the Helimak team agree with the density changes. The electric field derived from Langmuir probes is not trivial (especially in plasmas with flows) and was not computed for this thesis.en
dc.description.departmentElectrical and Computer Engineeringen
dc.format.mimetypeapplication/pdfen
dc.identifier.urihttp://hdl.handle.net/2152/20797en
dc.language.isoen_USen
dc.subjectPlasmaen
dc.subjectBeam probeen
dc.subjectNeutral Beam Probeen
dc.subjectIon gunen
dc.subjectEnergy analyzeren
dc.subjectHelimaken
dc.titleA Neutral Beam Probe for the Helimak plasma experimenten

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