results are useful when the incident atom has an energy of about 1 electron volt and the surface has a temperature less than or comparable to the Debye temperature. GRA 73 NUCLEAR AND HIGH-ENERGY PHYSICS Includes elementary and nuclear particles; and reactor theory. For space radiation see 93 Space Radiation. N89-28388# Utah Univ., Salt Lake City. Dept. of Chemistry. MODIFIED ROTATIONALLY ADIABATIC MODEL FOR ROTATIONAL AUTOIONIZATION OF DIPOLE-BOUND MOLECULAR ANIONS Technical Report No. 2, Jan. - Jun. 1989 Jack Simons (Joint Inst. for Lab. Astrophysics, Boulder, CO.) 28 Jun. 1989 24 p Submitted for publication (Contract N00014-89-J-1497; NSF CHE-88-14765) (AD-A209851) Avail: NTIS HC A02/MF A01 CSCL 07/2 Modifications are introduced to a rotationally adiabatic model developed and successfully applied by Clary to describe rotational autoionization of dipole-bound molecular anions. These modifications address branching ratios for forming neutrals in various final rotational states. Also produced are rate-enhancement corrections to the original model in the neighborhoods of channel openings. Example calculations are presented and the essential ingredients of the corrections are tabulated in a manner that permits straight-forward application to any linear or pseudo-linear anion. N89-28389# Chemistry. GRA State Univ. of New York, Buffalo. Dept. of EXTRAORDINARY BEHAVIOR OF ATOMS NEAR A PHASE CONJUGATOR Henk F. Arnoldus and Thomas F. George Jun. 1989 (Contract N00014-86-K-0043) (AD-A209946; UBUFFALO/DC/TR-103) Avail: NTIS HC A02/MF A01 CSCL 20/5 10 p An atom near a phase conjugator (PC) is theoretically seen to behave quite differently than an atom in empty space or an atom near an ordinary (linear) surface. With two laser beams which pump the nonlinear crystal (PC), it is found that an atom in its ground state can fluoresce if it is sufficiently close to a PC. The possible mechanism involves the atomic transition dipole polarizing the PC, which then spontaneously emits a photon focused on the atom. With stimulated absorption and subsequent spontaneous emission, the net effect is that the atom remains in its ground GRA state. ELECTROMAGNETIC REACTION TO MOLECULAR RELAXATION AND ITS EFFECT ON ABSORPTION NEAR A ROUGH SURFACE Jun. 1989 Purna C. Das, Ashok Puri, and Thomas F. George 20 p Submitted for publication (Contract N00014-86-K-0043) (AD-A210069; UBUFFALO/DR/TR-102) Avail: NTIS HC A03/MF A01 CSCL 07/4 The effect of electromagnetic reaction to relaxation of a molecule adsorbed on a rough surface is considered. The reaction fields are included due to the system dipole relaxing by both photon radiation and decay to delocalized surface plasmon damping is shown to be important for both small and large sized roughness features. GRA Jet Propulsion Lab., California Inst. of Tech., NEW ION TRAP FOR ATOMIC FREQUENCY STANDARD APPLICATIONS The In its 15 May 1989 J. D. Prestage, G. J. Dick, and L. Maleki Telecommunications and Data Acquisition Report (For primary document see N89-27871 22-32) p 58-63 Avail: NTIS HC A17/MF A01 CSCL 20H No abstracts in this category. 74 OPTICS Includes light phenomena; and optical devices. For lasers see 36 Lasers and Masers. N89-28391# Rockwell International Corp., Thousand Oaks, CA. Phase-conjugate gyroscopy is a new area promising significant advances in state-of-the-art inertial navigation. This contract demonstrated the first phase-conjugate fiber-optic gyros (PCFOG's) and their ability to use low cost multimode fiber components. The development of the PCFOG is now at the stage where its sources of noise and drift can be isolated, and its competitiveness with conventional fiber optic gyros can be tested. To come to this stage in development, several scientific and technical issues had to be resolved. For example, to correct for the modal scrambling of multimode fibers, the theory and practice of polarization preserving conjugators that worked at milliwatt power levels had to be developed and tested. Another issue was the mutual coherence requirement for two beams interacting with a self-pumped conjugator that at first restricted the PCFOG from using the most desireable form of biasing (fast phase modulation). This issue was resolved only recently when a new class of phase conjugators (mutually pumped conjugators) was developed that have the ability to operate with mutually incoherent beams. Almost as quickly as the first mutually pumped conjugators were discovered, this contract demonstrated the first PCFOG to use one. In addition to, and in the process of developing the PCFOG, this contract investigated several new photorefractive phenomena. (PB89-185318; OCS-TR-89-04) Avail: NTIS HC A03/MF A01 CSCL 20F The use of optical fiber for delay-line memory in LiNbO3-switch-based digital optical computers is investigated. Errors caused by the thermal sensitivity of optical fiber could lead to memory failure in a synchronous design if not properly controlled. Intermittent regeneration errors occur at the electro-optic boundary, in part due to optical attenuation. Fiber dispersion, switch crosstalk, polarization effects, and compositional variation in the switch are on the proposed expected to have negligible effects implementation. Suggestions for overcoming these limitations are presented, along with considerations for future developments. GRA SENSITIVITY ANALYSIS OF REFLECTION ERRORS IN INFRARED IMAGE SIMULATION B. E. Morey and D. J. Witte Sep. 1988 (Contract MDA908-87-C-3056) 44 P (AD-A208600; ERIM-205200-12-T) Avail: NTIS HC A03/MF A01 CSCL 17/5 The question of how much error is present in a simulated infrared signature if reflections are neglected was studied using a sensitivity analysis approach. The purpose was to determine whether it is necessary to model reflections in the current FSTC method of simulating IR signatures. To gain insight the following steps were performed. A sensitivity analysis approach was chosen for the study. An equation isolating the major components of an IR signature was derived. The equation was used to determine error present in a simulation when emissivity was estimated to be always 0.95. This was accomplished by using a simulation of a complicated tank applied with actual, measured emissivity that had specular characteristics. A weighted average error figure was derived and applied to the results of histogramming emissivities for the simulated tank. It was determined that in some cases, error could be as high as 35 percent on an absolute scale. However, most of the errors calculated in section 3.0 were found to be less than 10 percent, which corresponds to about 6 K apparent temperature error for ambient targets. GRA Robert G. Hohlfeld, Thomas W. Drueding, and John F. Ebersole 2 May 1989 35 p (Contract F19628-88-C-0151) (AD-A209955; COI-SR-31; GL-TR-89-0120) Avail: NTIS HC A03/MF A01 CSCL 20/6 Robust algorithms were demonstrated for generating fits in Optical Measure Theory (OMT) to radiance data from the TIROS Operational Vertical Sounder (TOVS). These algorithms generated physically meaningful fits on 100 percent of a test set of 45 TOVS radiance scans, and were successful both on short wavelength (667/cm) and on long wavelength (2250/cm) TOVS data. The resulting OMT temperature profiles exhibit meteorological characteristics and appear to be suitable for determination of atmospheric structure parameters characterizing the large-scale vertical temperature of the atmosphere, and also suitable for generation of input data for numerical weather prediction codes. GRA N89-28397# Environmental Research Inst. of Michigan, Ann Arbor. Optical Science Lab. GENERALIZED BEAMFORMING WITH MULTIPLE COMPUTER ORIGINATED HOLOGRAMS Final Report, Oct. 1985 - Oct. 1988 J. N. Cederquist, A. M. Tai, M. T. Eismann, M. A. Stuff, and J. R. Fienup Dec. 1988 102 p (Contract DAAL03-86-K-0006) (AD-A210175; ERIM-192400-13-F) Avail: NTIS HC A06/MF A01 CSCL 14/1 Generalized beamforming with optical systems using multiple computer-originated holographic optical elements (HOEs) was studied theoretically, through computer simulations, and through fabrication and experiments. A two HOE system was built for polar formatting of spotlight synthetic aperture radar data and was used with a spatial light modulator and a third phase-correcting HOE for real-time image formation. A two HOE system was designed using a novel iterative algorithm and successfully used for energy-efficient conversion of a Gaussian beam to a uniform far-field beam. A necessary condition was derived that a one-to-one coordinate transformation must satisfy to enable it to be performed with only two optical coordinate tranformations, each using the stationary phase approximation. Because of the importance of computer-generated holograms to this work, a brief study was made of computer-generated hologram fabrication facilities. N89-27942 ANT Nachrichtentechnik, Backnang (Germany, F.R.). CALCULATION OF PLANAR STRUCTURES FOR OPTICAL WAVELENGTH MULTIPLEXERS (BERECHNUNG PLANARER STRUKTUREN FUER OPTISCHE WELLENLAENGENMULTIPLEXER] Thomas Schwander In its Communication Engineering Reports. Fundamental Developments. Theoretical Work Nov. 1988 p 121-127 In GERMAN (For primary document see N89-27928 22-32) Copyright Avail: Fachinformationszentrum Karlsruhe, 7514 75 PLASMA PHYSICS 1988 p 271-274 Includes magnetohydrodynamics and plasma fusion. For ionospheric plasmas see 46 Geophysics. For space plasmas see 90 Astrophysics. N89-28398# Department of Energy, Washington, DC. Office of the Deputy Assistant Secretary for Oil, Gas, Shale and Special Technologies. MHD (MAGNETOHYDRODYNAMICS) PROGRAM PLAN, FY 1989 May 1989 43 p (DE89-012232; DOE/FE-0129) Avail: NTIS HC A03/MF A01 The essential elements of the current program, which is a continuation of the program outlined in the FY 1988 MHD Program Plan, are to: develop technical and environmental data for the integrated MHD topping cycle system through long-term (1000 hours) proof of concept (POC) testing; develop technical and environmental data for the integrated MHD bottoming cycle subsystem through long-term (4000 hours) POC testing; design and construct a seed regeneration system capable of independent operation, using spent seed materials from the MHD process; prepare a conceptual design for an MHD retrofit plant; and continue system studies and supporting research necessary for system testing. Results of the topping cycle POC tests at the Component Development and Integration Facility (CDIF), coupled with the bottoming cycle POC test results obtained at the Coal Fired Flow Facility (CFFF), and the seed regeneration POC effort will provide the critical engineering data base for the private sector's final decision on proceeding with the design, construction, and operation of an MHD retrofit. The development schedule, decision points, and resource requirements are discussed. As part of the MHD program, international activities of several nations are monitored and evaluated through contact with the international MHD scientific and technical community. N89-28399# Nagoya Univ. (Japan). Inst. of Plasma Physics. DOE K. Toi, K. Kawahata, S. Morita, T. Watari, R. Kumazawa, K. Ida, A. Ando, Y. Oka, M. Sakamoto, and Y. Hamada et al Apr. 1989 17 p Prepared in cooperation with Chubu Univ., Kasugai, Japan (IPPJ-906; ISSN-0469-4732) Avail: NTIS HC A03/MF A01 In a circular cross section plasma bounded by a limiter, the H-mode transition is triggered by rapid ramp-down in a plasma current during additional heating, even in the case that the edge electron temperature decays gradually prior to the transition. This result suggests that the enhancement of a magnetic shear near the plasma edge by the ramp-down plays a crucial role on the transition, and that the transition in a limiter-bounded plasma is essentially governed by the current density profile near the edge. Author N89-28400# Nagoya Univ. (Japan). Inst. of Plasma Physics. (IPPJ-905) Avail: NTIS HC A03/MF A01 Formulation is made to solve a 3-D MHD equilibrium problem on the basis of the coordinate transformation. The 3-D problem is divided into three steps: (1) the hyperbolic equations to determine the coordinate transformation; (2) averaged equation in 2-D; and (3) the 3-D elliptic equation to deal with magnetic potential. The usual stellarator approximation or averaging method is regarded as the first step of the iteration procedure to get the solution of the full 3-D problems. In formulating linear stability problem, the stellarator ordering is required; the resonance effect should be omitted in the averaging formulation. Some comparison is made to check the validity of the above formulation. Author N89-28401# Nagoya Univ. (Japan). Inst. of Plasma Physics. EXPERIMENTAL STUDY ON THE DEPOSITION PROFILE OF THE ICRF POWER AND ELECTRON THERMAL DIFFUSIVITY Y. Ogawa, R. Ando, E. Kako, K. Kawahata, Y. Kawasumi, S. Morita, T. Watari, R. Akiyama, Y. Hamada, and S. Hirokura Apr. 1989 27 P (IPPJ-908; ISSN-0469-4732) Avail: NTIS HC A03/MF A01 In lon Cyclotron Range of Frequencies (ICRF) heating experiments the deposition profile in electrons was derived experimentally, and comparison with theory was performed. It was found that the deposition profile is relatively broad (Prf,e(r) Prf,e(0)(1-(r/a)2)k with k = 1.8), and this is interpreted in terms of characteristics of the mode-converted lon Bernstein Wave. The distribution of the RF power to each species (electrons, hydrogen and deuterium ions) is in good agreement with theoretical predictions. With the deposition profile experimentally obtained, the electron thermal diffusivity Xe has been calculated, resulting in Xe approximately 0.65 m(2)/s at antineutron e 9x10(19) m(-3). N89-28402# Center. = Author Georgia Inst. of Tech., Atlanta. Fusion Research REVIEW OF EFFECTS OF NBI (NEUTRAL BEAM INJECTION) AND ROTATION ON PLASMA TRANSPORT IN TOKAMAKS Weston M. Stacey, Jr. Jun. 1989 20 p (Contract DE-AS05-78ET-52025) (DE89-014109; GTFR-91) Avail: NTIS HC A03/MF A01 The experimental and theoretical indications of effects of unbalanced neutral beam injection and plasma rotation on plasma transport in tokamaks are reviewed. N89-28403# Los Alamos National Lab., NM. THE STABILITY OF THE HIGH-DENSITY Z-PINCH DOE Presented at the A. H. Glasser and R. A. Nebel 1989 16 p 2nd International Conference on High-Density Pinches (ICHOP-2), Laguna Beach, CA, 26-28 Apr. 1989 (Contract W-7405-eng-36) (DE89-014276; LA-UR-89-2188; CONF-8904107-7) Avail: NTIS HC A03 Fiber-initiated High Density Z-Pinches at Los Alamos, NRL, and Karlsruhe have shown anomalously good stability. Kink modes are never seen, and sausage modes are at least delayed until late in the discharge. The success of these devices in reaching fusion conditions may depend on maintaining and understanding this anomalous stability. Two numerical methods were developed to study the stability in the regime where fluid theory is valid. While the methods are applicable to all modes, they are described only for the m = O sausage mode. The appearance of sausage modes late in the discharge and the total absence of kink modes suggest that an understanding of sausage modes is more urgent, and it is also simpler. DOE A novel high power millimeter/microwave source is proposed in which one or more pairs of interpenetrating streams of electrons, flowing through a background plasma in a static magnetic field are used to generate a hot-electron plasma that is confined in a mirror-like magnetic field. Energy stored in the anisotropic, hot-electron plasma is then used to amplify pulses of unstable plasma waves to large amplitude by selective deactivation of mechanisms that stabilize the hot-electron plasma during the energy accumulation phase when the density of hot electrons is rapidly increased through the beam-plasma interaction. The Phase 1 program has yielded a design for an experimental arrangement capable of verifying the key aspects of this novel source concept, as well as a theoretical framework for interpreting the empirical Phase 2 results produced by the experimental device and extrapolating those results to evaluate the suitability of the proposed source to meet the requirements of various high power microwave and millimeter wave defense and industrial applications. The experiments will be carried out in a timely and cost-effective way by employing the AMPHED (a CW magetic mirror) experimental facility at Applied Microwave Plasma Concepts (AMPC). GRA N89-28406# Central Inst. of Physics, Bucharest (Romania). SUPERCONDUCTIVITY IN THE Ba(0.69)Y(0.46)CuO(3.15-DELTA) COMPOUND I. Ursu, E. Labusca, I. Mihai, A. Novacu, H. Petrascu, and M. Petrascu Oct. 1987 5 p (DE88-706000; ICEFIZ-CS-12-1987) Avail: NTIS (US Sales Only) HC A02/MF A01 High critical temperature T sub c equals 119 K and onset temperature T equals 135 K was observed in Ba(0.69)Y(0.46) CuO(3.15-delta) compound. This compound corresponds to the calculated admixture of 80 percent of the superconducting Ba2YCuO(9 - delta) phase, with 20 percent of the semiconductor Y2BaCuO5 phas. A decrease in time was observed for T sub c, but also for the temperature width delta T. The zero resistence point and the onset temperature are not significantly modified after a period of 3 months. DOE Research on diffuse scattering from twist boundaries in gold is reported. In order to obtain an unambiguous measure of the diffuse scattering from the boundary, we developed a technique in which the total diffuse scattering is measured from the same specimen containing the boundary, and then not containing the boundary, and then determining any difference. This is accomplished by first measuring the diffuse scattering from the bilayer specimen containing the boundary. The specimen is then removed from its polymer film support and annealed gently at 175 C in order to convert the metastable layered bicrystal into a more stable structure consisting of columnar grains separated by short transverse boundaries. In this process, the original flat twist boundary is eliminated. The specimen is then remounted on a polymer film support in as reproducible a manner as possible, and the diffuse scattering is again measured. DOE The long reach goals are to obtain information on the atomic structure and properties of grain boundaries in bcc metals and ceramics, to understand how solute segregation influences grain boundary structure and causes boundaries to become embrittled in Fe-base alloys, to understand the role of boron and non-stoichiometry in making brittle boundaries in Ni3Al ductile, and to understand how solute segregation influences the boundary structure in ceramic materials. The topics covered are: the influence of solute segregation on the structure of grain boundaries in Fe-base alloys; and the influence of boron segregation on the structure of grain boundaries in Ni3AI. DOE database contains a growing list of references (approx. 5000) each of which is identified by a set of two letter keywords. The database is used the same way as as INSPEC's, but its fixed set of standard keywords enables the user to obtain a complete list of references on keyworded topics. Since a single keyword (or search term) such as sputtering creates a bibliography that is too long for practical use, the database is used most effectively by combining a series of keywords using Boolean algebra to identify a handful of relevant references. The structure of this document is intended to present the subset of papers concerning high T sub c films (725 papers) in a compact format as a substitute for on-line searches. Rather than listing separate bibliographies for each of the 185 keywords, a single list of all the references is contained in Section 6, and indices based on the keywords are contained in Sections 3 to 5. This is a true bibliography and does not contain any informative text. DOE Presented at the 22nd Jerusalem Symposium on Quantum Chemistry, Jerusalem, Israel, 15 May 1989 (Contract DE-AC02-76CH-00016) (DE89-013568; BNL-42831; CONF-8905146-1) Avail: NTIS HC A03/MF A01 Electron transfer matrix elements for electron exchange between various pairs of transition metal complexes in close contact have been calculated and analyzed for a variety of approach geometries for the two reactants. The coupling between the nominal metal ion donor/acceptor sites is achieved by superexchange of the hole type arising from ligand-to-metal charge transfer (LMCT), the dominant ligand-field interaction for the electron-donor ligands considered (H sub 2 O, NH sub 3, the cyclopentadienide anion). The pronounced variations of H sub if with geometry are not correlated with the separation distance of the metal ions (between which the direct overlap is negligible) and span the range from non-adiabatic to strongly adiabatic electronic coupling. The values for metallocene/metallocinium redox pairs bracket recently reported experimental values. Analysis of the results using the method of corresponding orbitals demonstrates the validity of an effective 1-electron model for the electron transfer process to within about 10 percent for the class of systems considered. A higher-order superexchange mechanism was encountered for the Co(NH sub 3) sub 6 (2+/3+) exchange process, in which the LMCT-driven hole-transport mechanism couples excited local states of the metal ions, which in turn are connected to the corresponding ground states by spin-orbit mixing. This mechanism yields on electronic transmission factor within two orders of magnitude of unity. N89-28412# Sandia National Labs., Albuquerque, NM. PHONON-DRAG THERMOELECTRIC POWER IN HIGH MAGNETIC FIELDS IN HETEROJUNCTIONS DOE S. K. Lyo 1989 (Contract DE-AC04-76DP-00789) (DE89-013921; SAND-89-0542C; CONF-890746-1) Avail: NTIS HC A02/MF A01 A theory is presented for the low-temperature (T) phonon-drag thermopower S sub xx in a semiconductor heterojunction in a strong magnetic field. Gigantic quantum oscillations (much larger than electron-diffusion contributions) are obtained. When the Landau-level width is larger than k sub B/T, the one-phonon intra-Landau-level absorption and emission processes are dominant. In the opposite limit, the two-phonon Raman processes give major contributions. The temperature and field dependences of S sub xx agree reasonably with recent data in GaAs Al sub x Ga sub 1-x/As heterojunctions. Effects of localized states on S sub xx are discussed. DOE Work is summarized for phase equilibria in II-VI quaternary systems over the last year. In general, the phase diagram depicts the geometric relationship among thermodynamic variables for phases in equilibrium with each other under an established set of conditions. Each type of thermodynamic system has a particular set of intensive variables which, when plotted against each other, best elucidate the equilibrium conditions. Isobaric, isothermal phase diagrams are used to predict solid state reactions in ternary and quaternary systems. This research has illustrated that a rigorous and methodical technique using the computer to construct quaternary phase diagrams can be successfully applied to a wide range of II-VI semiconductor systems, even for systems with solid DOE solubility. N89-28414# Sandia National Labs., Albuquerque, NM. E. L. Venturini, J. F. Kwak, D. S. Ginley, R. J. Baughman, and B. (DE89-014550; SAND-89-0506C; CONF-890718-6) Avail: NTIS HC A02/MF A01 Static magnetization data for a superconducting thin film based on the TI-Ba-Ca-Cu-O system are presented and discussed. The film, deposited by electron-beam evaporation onto a single crystal SrTiO3 substrate, consists of large grains of two superconducting structural phases with their crystallographic c axes normal to the substrate. It exhibits substantial transport critical current density, large diamagnetic shielding, and activated flux creep, consistent with strong intergranular links but weak flux pinning. N89-28415# Argonne National Lab., IL. DOE Presented at the Les Houches International Workshop on Number Theory and Physics, Les Houches, France, 7 Mar. 1989 (Contract W-31-109-eng-38) (DE89-014676; CONF-8903140-1) Avail: NTIS HC A03/MF A01 Grain boundaries are shown to be quasiperiodic tillings made of inflatable sequences of structural units. A general grain boundary is a quasiperiodic grid of dislocations with the same inflation multiplier (a quadratic irrational) in every direction. DOE |