Consideration is given to the stability of negative ion beams which are neutralized through ionization of a background gas. Two types of instabilities are examined. First, beam-plasma instabilities are analyzed with the dispersion relation showing that they are unimportant if the beam velocity is less than the electron thermal velocity. Second, results of a computer simulation on the flow of a cylindrical beam and the resulting background plasma show that when the background neutral gas density is less than or approximately equal to a critical density as instability occurs. This critical density is the density that would be needed to space-charge neutralize the beam if the positive ions were not retarded by the beam. An approximate dispersion relation indicates that the nature of the instability is a transverse positive-ion acoustic wave which couples to the beam.

We propose to study the utilization of high-temperature (approximately 2000-2500K) process heat from fusion reactors for large-scale chemical process applications. Of particular interest is the decomposition reaction, CO/sub 2/ ..-->.. CO + /sup 1///sub 2/O/sub 2/, which at 2500K should yield approximately 60 percent conversion to CO if O/sub 2/ is partially removed through an oxide membrane. Hydrogen can be derived from CO at lower temperatures by reacting CO with steam, and C can also be derived from CO by a disproportionation into C and CO/sub 2/ at approximately 1000K. These chemicals, CO, H/sub 2/, and C, form the basis for a multitude of non-electrical energy applications in the areas of transportation, industrial processes, and residential and commercial uses. In addition to the CO/sub 2/ decomposition process, we propose to explore a variety of ideas and evaluate them for scientific and economic merit. A follow-on research and development program will be proposed if the ideas prove promising.

A number of mechanical and electrical measurements were made on joints in typical conductors for the proposed mirror fusion test facility (MFTF) and high field test facility (HFTF). For such measurements, a commercially available cold-pressure-welding machine was used. For joints in the MFTF conductor, which has a large proportion of superconductor, joint strength approached conductor strength. For the HFTF conductor, where the Cu-to-superconductor ratio is 4.33/1, the joint is stronger than the conductor. Electrically, the joints were not superconducting.. While the resistance is higher than might be achieved by other forms of joining, we feel that the cold-weld joint has the advantages of simplicity, speed, reliability, and reproducibility. This makes the method attractive for MFTF, where resistance losses will be small compared with the total 4 K refrigeration requirements.

A particularly simple problem exhibiting stochasticity is the motion of a charged particle in a uniform magnetic field and a single wave. Detailed studies of this wave-particle interaction show the following features. An electrostatic wave propagating obliquely to the magnetic field causes stochastic motion if the wave amplitude exceeds a certain threshold. The overlap of cyclotron resonances then destroys a constant of the motion, allowing strong particle acceleration. A wave of large enough amplitude would thus suffer severe damping and lead to rapid heating of a particle distribution. The stochastic motion resembles a diffusion process even though the wave spectrum contains only a single wave. The motion of ions in a nonuniform magnetic field and a single electrostatic wave is treated in our study of a possible saturation mechanism of the dissipative trapped-ion instability in a tokamak. A theory involving the overlap of bounce resonances predicts the main features found in the numerical integration of the equations of motion. Ions in a layer near the trapped-circulating boundary move stochastically. This motion leads to nonlinear stabilization mechanisms which are described qualitatively.

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, John L. Hill, regarding a legal question submitted for clarification; Tax exemption for building to house the Courts of Civil Appeals in Harris County.

Efforts this past quarter were directed toward the determination of dissolution parameters in various reagents of PuO/sub 2/, PuO/sub 2/-UO/sub 2/ solid solution, and AmO/sub 2/-PuO/sub 2/. The reagents used were various concentrations of HNO/sub 3/-HF-H/sub 2/SO/sub 4/, HNO/sub 3/-HF, HNO/sub 3/-(NH/sub 4/)/sub 2/Ce(NO/sub 3/)/sub 6/, and HNO/sub 3/-H/sub 2/SO/sub 4/. In one series of tests, simulated contaminated HEPA filter media were used. This material was prepared by mixing shredded filter media with actinide oxides. In another series, actual HEPA glovebox filter media contaminated with PuO/sub 2/ were used. Fusion tests were also completed using simulated PuO/sub 2/ contaminated filter media. Both Na/sub 2/CO/sub 3/ and Na/sub 2/CO/sub 3/-KNO/sub 3/ were investigated as possible fusion agents.

Observations on the use of the SEMPEX computer code are given. The issues of proper sampling rate and total sampling interval are addressed. The effect that noise in the data has on the results and the ability of autocorrelation, truncation filtering, and the sliding-window technique to reduce these effects are also discussed. 35 figures, 24 tables.