Feasibility of an electromagnetic railgun as a high-velocity (~ 10 km/s) hydrogen pellet injector for refueling magnetic fusion reactors is investigated both experimentally and theoretically. A variety of advanced railgun configurations are considered, especially those which rely on magnetic propulsion of the pellet by a plasma-arc armature and which do not require a fuse to effect the system operation. The principal diagnostics used are laser interferometry, optical spectroscopy, streak camera, and magnetic probes. A CAMAC system is employed for data acquisition and processing. Using the present acceleration scheme a solid hydrogen pellet velocity in the range of 3.3 km/s has been demonstrated.

A novel scheme using electrohydrodynamic spraying of liquid-mix precursors is investigated for development of a method for fabricating thin films of metals, semiconductors, superconductors, and insulators. The same technique is also suitable for fabricating nanoparticles from a variety of liquid precursors. Unique aspects of this new technique are that it is inherently capable of producing a uniform, charged fine spray of liquid precursors of controlled size, chemical composition, and stoichiometry, and that the energy of the spray can be controlled, allowing for fabrication of high-quality films and uniform nanoparticles.

This work is intended to develop techniques that are most suitable for noncontact coating of spherical ICF targets. The work involves developing two different techniques: one that can stably levitate a microsphere a few hundred microns to a few milimeters in diameter and the other that can produce uniform coating on a levitated small object. The levitation schemes include acoustic and gas dynamic methods. The coating technique being investigated is known as field-injection electrostatic spraying in which a liquid precursor is sprayed into charged nanodrops which in turn are directed toward the levitated object.

The objectives of this work are twofold: to assess the feasibility of using electromagnetic (EM) forces for efficient removal of nitrocellulose fines from wastewater and to develop a prototype proof-of-principle system that can demonstrate the efficacy as well as practicality of the EM treatment scheme. The EM techniques are appealing since the concepts involved are usually simple and well understood, and the techniques can be implemented relatively inexpensively and reliably.

The objective of this work is to grow device-quality GaN-based films for fabrication of short-wavelength optical devices. The growth technique used is the plasma-assisted ionized source beam epitaxy that employs an atomic nitrogen beam from an rf-discharge nitrogen plasma and a partially ionized Ga source beam. The growth parameters under control are the power and frequency of the rf discharge, the energy and fraction of ionization of the Ga beam, the Ga and N fluxes, and the substrate temperature. The films are characterized using a variety of microanalysis techniques including RHEED, XRD, SEM, and TEM.

The objective of this work is to evaluate the use of the sol-gel process to render heavy metal wastes nonleachable. The precursor material used in this experiment is tetra ethoxylsilane, mixed with a solvent such as water or methanol, and an acid or base catalyst. In a typical proof-of-principle experiment, one adds a heavy-metal-contaminated solution to the mixture and, through sol-gel processing, fabricates a solid, nonleachable product. The target heavy metal for these evaluation experiments is lead.

This work is part of a DOE-sponsored Small Business Technology Transfer (STTR) program intended to develop a practical fusion fuel injection railgun system using low-ablation gunrails so that the injector system can not only achieve high fuel pellet velocities that are needed for fusion reactor refueling, but can also have a long life. The fuel injector is a two-stage acceleration system consisting of a gas gun preaccelerator and a railgun booster accelerator. The preaccelerator has a built-in cryostat that can produce frozen hydrogen pellets needed for the acceleration experiment.