This thesis covers work done on the mHTX@MIT helicon source as it relates to the analysis of power losses. A helicon plasma is a rather complex system with many potential loss mechanisms. Among the most dominant are optical radiation emission, wall losses due to poor magnetic confinement, and poor antenna-plasma coupling. This work sought to establish a first-order breakdown of the loss mechanisms in the mHTX@MIT helicon source so as to allow for a better understanding of the issues effecting efficiency. This thesis proposes the use of a novel thermocouple array, standard plasma diagnostics, and a simple global energy balance model of the system to determine greater details regarding the losses incurred during regular operation. From this it may be possible, by comparing the heat flux on the tube to the applied magnetic field profile, to gain some insight into the effects of magnetic field geometry on the character of the helicon discharge.

The development of plasma sources with densities and temperatures in the 1015-1017 cm−3 and 1-10eV ranges which are slowly varying over several hundreds of nanoseconds within several cubic centimeter volumes is of interest for applications such as intense electron beam focusing as part of the x-ray radiography program. In particular, theoretical work [1,2] suggests that replacing neutral gas in electron beam focusing cells with highly conductive, pre-ionized plasma increases the time-averaged e-beam intensity on target, resulting in brighter x-ray sources. This LDRD project was an attempt to generate such a plasma source from fine metal wires. A high voltage (20-60kV), high current (12-45kA) capacitive discharge was sent through a 100 [mu]m diameter aluminum wire forming a plasma. The plasma's expansion was measured in time and space using spectroscopic techniques. Lineshapes and intensities from various plasma species were used to determine electron and ion densities and temperatures. Electron densities from the mid-1015 to mid-1016 cm−3 were generated with corresponding electron temperatures of between 1 and 10eV. These parameters were measured at distances of up to 1.85 cm from the wire surface at times in excess of 1 [mu]s from the initial wire breakdown event. In addition, a hydrocarbon plasma from surface contaminants on the wire was also measured. Control of these contaminants by judicious choice of wire material, size, and/or surface coating allows for the ability to generate plasmas with similar density and temperature to those given above, but with lower atomic masses.

This book highlights a high-density helicon plasma source produced by radio frequency excitation in the presence of magnetic fields, which has attracted considerable attention thanks to its wide applicability in various fields, from basic science to industrial use. Presenting specific applications such as plasma thrusters, nuclear fusion, and plasma processing, it offers a review of modern helicon plasma science for a broad readership. The book covers a wide range of topics, including the fundamental physics of helicon plasma and their cutting-edge applications, based on his abundant and broad experience from low to high temperature plasmas, using various linear magnetized machines and nuclear fusion ones such as tokamaks and reversed field pinches. It first provides a brief overview of the field and a crash course on the fundamentals of plasma, including miscellaneous diagnostics, for advanced undergraduate and early graduate students in plasma science, and presents the basics of helicon plasma for beginners in the field. Further, digesting advanced application topics is also useful for experts to have a quick overview of extensive helicon plasma science research.