Detailed Computer Simulation of an Axial Cylindrical Inertial Electrostatic Plasma Confinement Fusion Neutron Device
R. A. Axford,* B. P. Bromley
University of Illinois

A time-dependent, spatially 2-D (r,z), particle-in-cell, Monte Carlo collision (PIC-MCC), multiple-species computer simulation model is under development to predict the plasma physics behavior and fusion neutron rate of an axial-cylindrical inertial electrostatic plasma confinement fusion device (IEC C-device). Theoretical results will be benchmarked with recent experimental data. The C-device uses a symmetric arrangement of biased hollow ring electrodes to accelerate and confine fusion fuel plasma in axial and radial directions at high densities and energies. The C-device could be used as a near-term neutron source and a future power generator if the plasma confinement can be successfully understood, enhanced, and exploited.

Spherical and Cylindrical Inertial Electrostatic Confinement (IEC) Fusion Research
G. H. Miley,* L. Chacon, J. DeMora, B. Jurczyk, M. Nieto, R. Stubbers, M. Williams
Daimler-Chrysler Aerospace

The IEC uses a central cathode grid to ionize a low-pressure gas within either a spherical or cylindrical vacuum chamber. Ions are extracted and accelerated to high energies by the grid and are focused at the center of the chamber, creating a high-density fusing plasma core. Experiments have yielded over 106 steady-state D-D fusion neutrons per second in both configurations. The objective now is to further improve performance by pulsed high-current operation for greater fusion neutron yield, investigation of forced and natural plasma oscillations for plasma core densification, study of electrode grid and insulator design for increased ion confinement and for grid lifetime extension. Also under investigation are gas mixture separation for plasma processing and IEC jet mode operation for space thruster applications.

Collision Modeling of Inertial Electrostatic Confinement (IEC) Systems
G. H. Miley,* J. DeMora, R. Stubbers
Daimler-Chrysler Aerospace

IEC devices typically run at low gas pressures (1-10 mTorr), which provide a plasma that is mostly collisionless. However, the collisions that do occur, especially charge exchange, significantly alter the ion energy distribution within the IEC. This in turn affects the fusion rate. Computational studies have been undertaken to determine the effects of charge exchange, impact ionization, and other collisions in an IEC device. Preliminary results indicate that under typical conditions, the average ion energy is reduced to 80% of the applied voltage for small (1 cm radius) grids, and 60% for larger (3 cm radius) grids. The computational model is now being used to optimize the IEC design so that collisional losses are reduced, maximizing the neutron yield.

Modeling of Double Potential Wells Formation on Spherical IEC Devices Using EIXL
G. H. Miley,* R. Stubbers, M. Nieto
Daimler-Chrysler Aerospace; USIA-Fulbright

The formation of double potential wells in spherical IEC devices is a crucial step for a good confinement in this type of apparatus. Using the EIXL code, a one-dimensional Vlasov-Poisson solver, the parameter space is being explored to find the optimal set of these parameters for the development of an adequate double potential well, resulting in better performance of a real IEC. Some of these parameters are ion angular momentum, ion perveance, and electron-ion current ratio. A further step will be the addition of more capabilities to the code, such as allowing modeling of charge exchange between neutral fuel atoms and ions.

Coherent Lattice Accelerator Interionic Reactions Enhancer (CLAIRE)
G. H. Miley,* G. Selvaggi, V. Violante
ENEA, Frascati

CLAIRE is an integrated software package developed to simulate the dynamics of charged particles within a metal lattice like palladium or nickel when hydrogen or deuterons were loaded into the metal. It is assumed that the oscillations of the metal atoms electrons develop coherently and that the hydrogen or deuterons to metal ratio is very high. The analysis of the dynamics of the moving particles is obtained by means of a numerical solution of the classical differential equations of the motion. The goal is to simulate low-energy nuclear reactions experiments and to compare the data with experimental results. The first case under study concerns proton-nickel interactions in a dipole potential trap signal.

Low-Energy Nuclear Reactions in Thin Films
G. H. Miley,* M. Williams, A. Tate, G. Selvaggi
Clean Energy Technologies, Inc.

Part of the research in the Low-Energy Nuclear Reaction (LENR) Lab consists of an experiment that uses either an electrolysis process, a high-pressure process, or an arc process to force hydrogen atoms into the lattice structure of a thin film (500-3500 Å) of metal. In this manner a very high loading, approaching 1 atom H/atom metal is achieved, a necessary condition for LENRs. One of our major goals is to examine the metal before and after the experiment, to establish the signatures of LENRs by studying transmutation products. Another goal is to measure the energy output of the unit. If an ample amount is released, such cells offer an attractive small power source for future distributed energy systems.

Ion Defocusing in Inertial Electrostatic Confinement (IEC) Fusion Devices
G. H. Miley,* L. Chacon, D. Barnes
Daimler-Chrysler Aerospace; Los Alamos National Laboratory

The IEC concept requires maintaining a beam-like ion distribution to provide high fusion energy gains. However, ion-ion collisions tend to drive the system to thermal equilibrium, thus degrading the ion beams. A bounce-averaged Fokker-Planck code (BAFP) is being developed to find the actual degree of ion defocusing in spherical IEC systems; ion-electron and electron-electron collisions are not handled. Electrons in the system are assumed to distribute in two energy groups (high and low energy), and the parameters describing each group are determined from a zero-dimensional particle and energy balance model. The potential profile within the device is determined self-consistently by solving Poisson's equation in spherical geometry.

A Traveling Wave Direct Energy Converter for Advanced Fusion
G. H. Miley,* H. Momota (Nagoya Univ.), M. Ishikawa (Tsukuba Univ.)
National Institute for Fusion Sciences, Japan

The principle of the traveling wave direct energy converter mechanism is understood as a combination of a traveling wave tube and a linear accelerator. 3-D numerical simulations are being carried out to optimize device parameters. Self-excitation of an alternative electric power in the transmission circuit was with a theotical analysis as well as by 3-D numerical simulations. Based on parameters from a conceptual reactor study, a conversion efficiency as high as 69.8% is predicted.

Modeling of Ion and Neutral Atom Interactions and Hydrocarbons at Low Energies
D. N. Ruzic,* D. Alman
Argonne National Laboratory, ANL 20442401

Recycling is the process by which particles are returned to a plasma. Recycling in magnetic fusion devices is dominated by the surfaces in contact with the plasma-walls, limiters, and divertor plates. To understand and possibly control recycling it is necessary to know the ion and neutral atom energy and particle emission coefficients for a variety of materials at the energy of the incident particles, 1-1000 eV. New models that include sputtering, reflection, and the transport particularly of hydrocarbons in the plasma are being developed and applied to current fusion research devices.

Design Considerations for the Edge Region of the International Thermonuclear Experimental Reactor
D. N. Ruzic,* D. Hayden, D. Alman
U.S. Department of Energy, DE-FG02-89ER52159

Russia, Japan, Western Europe, and the United States are jointly designing a tokamak reactor that will achieve and sustain fusion ignition. One region of particular concern is the edge region where the plasma strikes the wall. The helium produced by the fusion events needs to be exhausted, and the power load must not melt the wall and contaminate the plasma. Complete modeling of this edge region, including the detailed macroscopic and microscopic geometry and neutral atom scattering, is of critical importance.

Tritium Retention and Throughput in TFTR
D. N. Ruzic,* M. Allain
U.S. Department of Energy, PPPL-S-03436-G

Tritium has been introduced into the TFTR tokamak over the last few years. Because of on-site inventory restrictions, a complete model of where the tritium will be retained and how much will recycle in each discharge has been developed. A combined experimental and computational approach has predicted inventory totals. The isotropic exchange in the walls between will be measured using H and D instead of T and D. Three-dimensional modeling of neutral atom transport and plasma wall interactions has been checked against this experiment and extended to the decommissioning phase of operation.