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We describe the operation of a silicon optical nanocrystal memory device. The programmed logic state of the device is read optically by the detection of high or low photoluminescence intensity. The suppression of excitonic photoluminescence is attributed to the onset of fast nonradiative Auger recombination in the presence of an excess charge carrier. The device can be programmed and erased electrically via charge injection and optically via internal photoemission. Photoluminescence suppression of up to 80% is demonstrated with data retention times of up to several minutes at room temperature.

Contents: Nonlinear Effects in Quto-resonant Acceleration; Stability of Slab Electron Beam Equilibria; Limiting Currents of an Unneutralized Magnetized Electron Beam in a Cylindrical Drift Tube; Influence of Spatial Variation in Gamma on the Relativistic Electron Beam Cyclotron Mode; Relativistic E-Beam Plasma Heating; Letter Summary of Beam-Plasma Heating Research and Comparison of Results with those of Thode, et al; Self Consistent Equilibria of Unneutralized Relativistic Electron Beams; Linear Theory of Collective Waves Supported by an Unneutralized Relativistic Electron Beam; Linear Theory of Plasma Waves Supported by a Radially Varying Electron Beam in a Magnetized Waveguide; and The Effects of Finite Thermal Spread on the Electron Cyclotron Beam Modes.

During the performance period on this contract, 30 June 1976, substantial progress has been made in our research on the interactions of high energy beams of charged particles. The mechanisms and efficiency of energy transfer have been investigated from relativistic electron beams to much denser, high-z target plasmas. Provided that the beam quality is sufficiently well controlled, optimization of the primary beam-plasma interaction, through selection of beam density and energy, should permit at least 15% of the beam energy to be deposited during a single pass in targets near 100,000 times as dense as the beam. Estimation of ionization and radiation processes indicate that a beam-heated plasma source of multi-kilojoule, multigigawatt radiation in the 10 - 10,000 eV portion of the photon energy spectrum may be achievable. More recently a number of calculations have been completed relevant to the development of collective ion accelerators. Required conditions have been determined for both equilibria and stability of powerful, unneutralized electron beams propagating along a magnetic guide field. Also studied were the collective ionelectron cyclotron interaction which can occur between a non-neutral ultra-relativistic electron beam and a less dense species of ions. Various regimes of this interaction have been investigated, and in one important regime for which the instability growth rate is less than the transverse bounce frequency of the ions in the radial electric field of the electron beam, two dimensional computer simulations have been performed.

A detailed examination of the principle of Auto-Resonant acceleration has been undertaken. This investigation, including both theoretical and computational analysis, has delineated the requirements and limitations on electron beam parameters, magnetic field configurations, ion current, and wave growth mechanisms which must be met for proper functioning of an Auto-Resonant Accelerator. (Author)

A detailed examination of the principle of Auto-Resonant acceleration has been undertaken. This investigation, including both theoretical and computational analysis, has delineated the requirements and limitations on electron beam parameters, magnetic field configurations, ion current, and wave growth mechanisms which must by met for proper functioning of an Auto-Resonant Accelerator. (Author)

Equations are derived for the direct evaluation of a sonar pulse reflected from a time-varying ocean surface. Fewer assumptions and approximations are made in this direct approach than in conventional developments of scattering theory. However, the cost of computer time may become excessive for some cases. The calculated surface reflected signals are correlated with the incident sonar pulse to find the expected correlation loss of a sonar processor. For a short (5 msec) low frequency FM slide the calculated correlation losses (1.6 dB for the surface generated by a 10 knot wind and 3.9 dB for a 20 knot wind) were almost entirely the result of energy loss in the reflected signal. (Author)