Recent measurements of nonsolar isotopic patterns for the elements neon and (perhaps) magnesium in cosmic rays are interpreted within current models of stellar nucleosynthesis. One possible explanation is that the stars currently responsible for cosmic-ray synthesis in the Galaxy are typically super-metal-rich by a factor of two to three. Other possibilities include the selective acceleration of certain zones or masses of supernovas or the enhancement of /sup 22/Ne in the interstellar medium by mass loss from red giant stars and planetary nebulas. Measurements of critical isotopic ratios are suggested to aid in distinguishing among the various possibilities. Some of these explanations place significant constraints on the fraction of cosmic ray nuclei that must be fresh supernova debris and the masses of the supernovas involved. 1 figure, 3 tables.

Refined nuclear analysis, including the treatment of resonance and spatial self-shielding, coupled with an optimization procedure, has resulted in improved performance estimates for two conceptual fission-suppressed blankets. Net specific breeding in these two blankets maximized at 0.024 and 0.023 U-233 atoms/MeV, which is about an order of magnitude higher than in fission breeders.

Advanced wave models used to evaluate ICRH in tokamaks typically use warm plasma theory and allow inhomogeneity in one dimension. The majority of these calculations neglect the fact that gyrocenters experience the inhomogeneity via their motion parallel to the magnetic field. The non-local effects of rotational transform and toroidicity can play a significant role in both the propagation and the absorption physics. In strongly driven systems, wave damping can distort the particle distribution function supporting the wave and this produces changes in the absorption. The most common approach is to use Maxwellian absorption rates. We have developed a bounce-averaged Fokker-Planck quasilinear computational model which evolves the population of particles on more realistic orbits. Each wave-particle resonance has its own specific interaction amplitude within any given volume element; these data need only be generated once, and appropriately stored for efficient retrieval. The wave-particle resonant interaction then serves as a mechanism by which the diffusion of particle populations can proceed among neighboring orbits. The local specific spectral energy absorption rate is directly calculable once the orbit geometry and populations are determined. The code is constructed in such fashion as to accommodate wave propagation models which provide the wave spectral energy density on …

Four accelerator parameters were found to control the condition of the electron beam entering the Intergrated Fast Reactor (IFR). These parameters were the matching of the electron beam to the ion channel, the laser timing, the benzene pressure at the entrance to the IFR, and the timing of the accelerator gaps. Manipulation of these parameters make possible the control of the total current, the emittance, the pulse length, the mixture of laser induced current and cathode current, the radial growth in time, the final size of the beam, and the energy variation through the pulse. 1 fig.

MINIMARS is a conceptual fusion reactor based on tandem-mirror magnetic confinement. It is designed to produce 600 MW net electric for 41 mils/kWh and to be capable of passive shutdown and afterheat removal.

This paper presents a study of the stability of subcritical neutronic modes in boiling water reactors that can result in out-of-phase power oscillations. A mechanism has been identified for this type of oscillation, and LAPUR code has been modified to account for it. Numerical results show that there is a region in the power-flow operating map where an out-or-phase stability mode is likely even if the core-wide mode is stable. 4 refs., 7 figs.