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.

Helicon plasmas are high density, low temperature plasmas with applications in particle accelerators, space thrusters, and current drive in tokamaks. While efficient ion production is often the chief interest in helicon plasmas, no theory explaining the mechanism behind the high ionization efficiency has been demonstrated through consistent measurement. Particle balance, power balance, and radio frequency (RF) wave coupling all play a role in determining the ionization rate and source distribution. In this work, significant upgrades and diagnostic improvements on the MARIA helicon device in the 3D Plasma Surface Interaction laboratory are presented. Laser induced fluorescence (LIF) measurements are calibrated against an RF compensated Langmuir probe to produce particle flux measurements at several magnetic field strengths and axial positions. Under the assumption that parallel transport is dominant, one dimensional mass and momentum conservation arguments are used to measure the distribution and magnetic field strength scaling of an ionization source in the range of 8x1020 m-3s-1. Axial and radial LIF measurements of neutral argon reveal a region of high recycling near an on axis boundary plate, and a 90% depletion of neutral particles near the helicon antenna. Measurements of radial ion losses and neutral source terms are also measured and presented. By identifying both particle sources and sinks, an understanding of the circular refueling process by recycling neutrals begins to form. Additionally a new collisional radiative model developed in collaboration with Auburn University is presented. Comparisons between solutions to the collisional radiative model and experimental results provided valuable insight into the behavior of atomic population processes occurring in MARIA plasmas. Additionally, the collisional radiative model is used in concert with line ratio spectroscopy to establish a new passive diagnostic for neutral dominated argon plasmas. Agreement with Langmuir probe electron temperature measurements is currently achievable, but additional work is needed to improve the extraction of electron density.

Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

These conference proceedings present 165 papers in all scientific and aerospace engineering fields, including materials and structures, aerodynamics and fluid dynamics, propulsion, aerospace systems, flight mechanics and control, space systems, and missions. Keywords: Aerospace Shell Structures, MCAST's Aerospace Program, Sandwich Structures, Thermal Buckling, Simulation of Elastodynamic Problems. Statically Deflected Beam, Meshes with Arbitrary Polygons, Variable Stiffness Composite Panels, Mechanical Response of Composites, 3D Printing Technique, Hygrothermal Effects in Composite Materials, Freeze-Thaw Cycling, Polymer Matrices, Morphing Aileron, Thermo-Elastic Homogenization of Polycrystals, Flutter Instability in Elastic Structures, Adaptive Composite Wings, Cylindrical IGA Patches, TRAC Longerons, Structural Damage Detection, Fatigue Behavior of Stiffened Composite Components, Redesign of Composite Fuselage Barrel Components, Damage Modelling of Metallic Lattice Materials, Ceramic Matrix Composites, Peridynamics Elastoplastic Model, Structural Batteries Challenges. Dynamic Buckling Structural Test, Delamination Identification on Composites Panels. CubeSat Radiative Surface, Wind Tunnel Testing.

As the twenty-first century progresses, plasma technology will play an increasing role in our lives, providing new sources of energy, ion-plasma processing of materials, wave electromagnetic radiation sources, space plasma thrusters, and more. Studies of the plasma state of matter not only accelerate technological developments but also improve the