Papers and abstracts of papers are presented concerning structures of solids, lattice dynamics, molecular dynamics, phase transitions, hydrides, magnetic moments, magnetic excitation, gases, liquids, and neutron optics. Sixty-two of the papers were processed individually. Other papers were processed separately. See CONF-760601-- in the Report Number Index. (JRD)

Problems involved in assessing health effects of chronic low-level exposures to environmental contaminants are reviewed. This problem is illustrated by a study of health effects of occupational exposure to ionizing radiation at Hanford. Hanford was established in the early forties as an installation for plutonium production. Since this time, over 33,000 workers have been employed, many in jobs involving some exposure to radiation. Yearly records of this exposure, as well as occupational data, are maintained for all such employees. The yearly exposures are measured in rems of ionizing radiation able to reach critical organs of the body. Even for those who routinely work in radiation zones, yearly readings seldom exceed one or two rems. Methods for assessing directly the health effects of continuing relatively small doses of radiation over a number of years are discussed that should be applicable to evaluating exposures to other industrial and environmental contaminants.

Optical sensors, such as solid state photodetector arrays can provide a basis for high speed, high accuracy gauging systems. The electro-optical nature of these devices requires design attention in three areas; optics, electronics and mechanical design. The interrelation of these parameters and two potential gauging concepts is discussed.

The targets used for the creation of laser produced plasmas often contain sodium, silicon and other period 3 elements. Temperature and density information can be inferred from detailed study of the characteristic radiation from these elements. The resolution capabilities of crystal spectrographs designed to look at such target radiation are discussed. Data from several types of spectrographs are compared. The fine structure of the hydrogen and helium-like silicon lines are used to illustrate spectrograph resolution. A spectrograph for examining weak characteristic radiation near 1 keV due to plasma which has been compressed with a spherical irradiation system is discussed.

A study is presented of electron density fluctuations in the ATC using both microwave and CO/sub 2/ laser scattering. Fluctuations with wavelength between 2 cm and 0.3 mm and with frequencies up to 1.5 MHz was observed. Their amplitude n/sub e//anti n/sub e/ is of the order of 10/sup -2/. Local measurements of the safety factor q and Z/sub eff/ are reported. The value of q was obtained from the shifts of injected ion orbits relative to the magnetic surfaces; Z/sub eff/ was obtained from the scattering rate of radially localized injected ions. Both these measurements indicate a peaking of Z/sub eff/ on axis. Measurements are presented of the parallel and anti-parallel fast neutral spectra which indicate very different profiles for T/sub i parallel/ and T/sub i anti-parallel/.

Measurements of the properties of subnanosecond, quenched NE111 plastic scintillators with various concentrations of acetophenone and benzophenone are presented. These quenching agents have been found to very significantly decrease the NE111 decay time. Measurements are made using UV and laser produced x-ray radiations. The scintillations are detected using a visible streak camera with 10 ps resolution. Measurements of: (1) 10-90 percent rise time, (2) FWHM, (3) decay time, (4) relative scintillator efficiencies, and (5) amplitudes vs. time measurements of the long decay component are presented. All temporal measurements are obtained from a gold cathode ultrafast x-ray streak camera, and the detailed x-ray energy spectrum above 1 keV is also measured using an array of x-ray PIN diodes equipped with the appropriate K-edge filters. Details of the experimental measurements are discussed and anticipated applications are included.

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Separate abstracts were prepared for 27 papers. For papers previously abstracted see CONF-760601-- in the Report Number Index.

There is considerable recent interest in the use of high energy (..gamma.. = 1.1), heavy (A greater than or equal to 100) ions to irradiate deuterium--tritium pellets in a reactor vessel to constitute a power source at the level of 1 GW or more. Various accelerator configurations involving storage rings have been suggested. A discussion is given of how the technology of Linear Induction Accelerators--well known to be matched to high current and short pulse length--may offer significant advantages for this application.

A brief outline of existing medical heavy-ion facilities is given. The beam specifications for future dedicated medical ion accelerators are discussed. Machines capable of delivering dose rates of approximately 1 krad/min in volumes of a few liters are shown to represent existing technology. A cost and performance analysis shows the synchrotrons to be the most economical source for the heavier ions while conventional cyclotrons seem optimal for an exclusive proton facility. It is seen that the incorporation of additional capabilities such as neutron generation or radioisotope production can be achieved at modest incremental costs. In addition to the accelerators, feasible layouts of hypothetical facilities are discussed, and three-dimensional beam scanning is shown to allow the irradiation of large volumes without sacrificing the precise dose localization capabilities of heavy-ion beams. Concepts of quality-controlled engineering and modern computer technology are introduced as a means to obtain the desired high degree of reliability and ease of operation and maintenance.

In recent years several techniques have become available to characterize the structure and chemical composition of surfaces of ceramic materials. These techniques utilize electron scattering and scattering of ions from surfaces. Low-energy electron diffraction is used to determine the surface structure, Auger electron spectroscopy and other techniques of electron spectroscopy (ultraviolet and photoelectron spectroscopies) are employed to determine the composition of the surface. In addition the oxidation state of surface atoms may be determined using these techniques. Ion scattering mass spectrometry and secondary ion mass spectrometry are also useful in characterizing surfaces and their reactions. These techniques, their applications and the results of recent studies are discussed. 12 figures, 52 references, 2 tables.

The Livermore 15 psec x-ray streak camera has been used in conjunction with 6 ..mu..m diameter pinholes to record well resolved implosion histories of DT filled laser fusion targets. The space-time compression data provide clearly identified implosion velocities, typically 3 x 10/sup 7/ cm/sec for two-sided clamshell irradiation of a 70 ..mu..m/sup D/, .5 ..mu..m wall DT filled glass microshell. Single-sided irradiation results show hydrodynamic convergence at the target center, followed by an asymmetric but two-sided target disassembly. These experiments were performed at the two arm Janus Laser facility, which typically delivered a total of 0.4 TW in a 70 psec pulse for these experiments.

This paper analyzes several important features of trapped-particle instabilities. For trapped-electron modes, the complete two-dimensional (2D) spatial structure, including the effects of magnetic shear, is numerically calculated within the framework of a differential formulation for long radial wavelength modes. Growth rates obtained for representative cases correlate reasonably well with the usual one-dimensional (1D) estimates of shear stabilization. However, the spatial structure of the mode differs markedly; e.g., it typically extends over several mode-rational surfaces. At the shorter wavelengths, where the maximum growth rates of the modes typically occur, it is necessary to introduce an integral equation formulation for calculating the radial dependence. Growth rates from this 2D analysis are significantly smaller than 1D estimates, and the poloidal mode structure exhibits a pronounced localization at the magnetic field minimum. Specific collisional mechanisms affecting the linear stability of these modes are also studied. Collisional scattering of low energy electrons can reduce the nonadiabatic trapped-electron response, and collisional broadening can strongly modify the resonant response of the untrapped electrons. The saturation of the usual form of the dissipative trapped-ion instability by mode coupling is studied analytically and numerically.

A survey of high-energy nucleus--nucleus experiments performed at the Berkeley Bevalac Facility is presented. Experimental results are divided into the general areas of peripheral and central collisions. Results on projectile and target fragmentation, total cross-section measurements, pion and photon production, and charged-particle multiplicities are stressed. Recently, there have been theoretical predictions concerning the possibility of observing new phenomena such as shock waves, pion condensates, or collapsed nuclear matter. Existing data relevant to some of these speculations are discussed. A brief discussion of future developments with high-energy nuclear beams is also presented. 27 figures, 1 table.

Irradiation experiments were performed with the two beam Nd:YAG glass laser systems, Janus(approximately less than 40 J/100 psec, approximately 0.4 TW), Cyclops (approximately less than 70 J/100 psec, approximately 0.7 TW), and Argus (approximately less than 70 J, 35 psec, approximately 2 TW). Two classes of targets have been used, glass microshells (approximately 40 to 120 ..mu..m diameter x approximately 0.75 ..mu..m wall thickness) filled with an equimolar DT mixture and disks (approximately 160 to 600 ..mu..m diameter x approximately 10 ..mu..m thick) of several compositions. The targets were supported in vacuum (pressure approximately less than 10/sup -5/ Torr) by thin glass stalks. This paper reports results related to the propagation, absorption and scattering of laser light by both spherical and planar targets. The absorption measurements cannot be explained using only inverse Bremsstrahlung. The scattered light and the plasma energy are polarization dependent, which is evidence of resonance absorption. The x-ray spectra are characterized by a thermal and a suprathermal distribution. The ''temperature'' of the hot x-rays is given by theta/sub H/ approximately equals I./sup 3/-./sup 4/ depending on the target material. Evidence is also presented which indicates that the laser radiation pressure is producing density steepening in the region …

The incentive for high density operation of a tokamak reactor was discussed. It is found that high density permits ignition in a relatively small, moderately elongated plasma with a moderate magnetic field strength. Under these conditions, neutron wall loadings approximately 4 MW/m/sup 2/ must be tolerated. The sensitivity analysis with respect to impurity effects shows that impurity control will most likely be necessary to achieve the desired plasma conditions. The charge exchange sputtered impurities are found to have an important effect so that maintaining a low neutral density in the plasma is critical. If it is assumed that neutral beams will be used to heat the plasma to ignition, high energy injection is required (approximately 250 keV) when heating is accompished at full density. A scenario is outlined where the ignition temperature is established at low density and then the fueling rate is increased to attain ignition. This approach may permit beams with energies being developed for use in TFTR to be successfully used to heat a high density device of the type described here to ignition.

A defect center with a single acceptor level at E/sub v/ + 0.08 eV appears in H/sub 2/-grown dislocation-free high-purity germanium. Its concentration changes reversibly upon annealing up to 650 K. By means of Hall-effect and conductivity measurements over a large temperature range the temperature dependence of the steady-state concentration between 450 and 720 K as well as the transients following changes in temperature were determined. The observed acceptor level is attributed to the divacancy-hydrogen complex V/sub 2/H. The complex reacts with hydrogen, dissolved in the Ge lattice or stored in traps, according to V/sub 2/H + H reversible V/sub 2/H/sub 2/. An energy level associated with the divacancy-dihydrogen complex was not observed. These results are in good agreement with the idea that hydrogen in germanium forms a ''very deep donor'' (i.e., the energy level lies inside the valence band).

In the Elmo Bumpy Torus Reactor (EBTR) study the feasibility of achieving a fusion power plant based on the EBT confinement concept was evaluated. If the present understanding of the physics can be extrapolated to reactor scale devices the reactor could operate at high beta, high power density, and at steady state. The high aspect ratio of the device eases the accessibility, structural design and remote maintenance problems which are common to low aspect ratio machines. A version of the EBTR reference design described here could be constructed with only minor extrapolations in available technology.

The Energy Research and Development Administration (ERDA) is sponsoring a program to explore the possibilities for beneficially using the temperature difference between warm surface water of the tropical oceans and the deeper colder water to operate a heat engine. Because as much as 4 to 6% of the expected demand for power in the United States by 2020 could be supplied by this source which is known as ocean thermal energy conversion, this is one of the potential alternatives being explored by the Federal Government to lessen our dependence upon conventional energy sources. One of the major technical hurdles that must be overcome to bring this alternative energy source into beneficial use is the solution to biofouling problems that are expected to impede efficient heat transfer in the power plant evaporator and condenser systems. There are allied problems in the corrosion of materials that must also be solved. In January 1976, ERDA established a project office at Battelle-Northwest whose mission it is to develop, procure and monitor projects to define, control and alleviate biofouling and corrosion problems expected in OTEC power plants. Since startup, this project office has developed a methodology to guide work in this area, assumed control of …

Required values of thermonuclear energy-gain, inertial confinement, laser-pulse energy and power for both electric power production by laser-fusion and for plutonium breeding by laser fusion-fission are obtained from simple considerations, and are tabulated for purposes of comparison. It is found that breeder requirements are very significantly less demanding, suggesting that plutonium breeding is a much more feasible near-term goal of laser fusion.

A small man-portable neutron detector was constructed using 18 /sup 3/He proportional counters arranged in three layers within a polyethylene moderator. Each counter is 25 mm in diameter by 340 mm long (sensitive length) and is filled with highly-purified /sup 3/He to a pressure of 400 kPa (4 atm). Efficiency measurements were made using a /sup 252/Cf neutron source. Detailed calculations of the detector efficiency were done using the TART Monte Carlo transport code. Calculations and measurements were compared for several source/detector configurations.

To increase the reliability of the criticality monitoring system in a diagnostic chemistry area and to reduce the number of false alarms, a new monitoring system was built using a fast-neutron detector. This paper outlines the design requirements, describes the plastic scintillation detector system as it was built, and reports on the results of several months of operation. The new monitor has proven much more useful than the gamma-detector system it replaced.

Lawrence Livermore Laboratory and Bechtel Corporation have been involved in a joint effort to conceptually design a laser fusion hybrid reactor. The design which has evolved is a depleted-uranium fueled fast-fission blanket which produces fissile plutonium and electricity. A major objective of the design study was to evaluate the feasibility of producing fissile fuel with laser fusion. This feasibility evaluation was carried out by analyzing the integrated engineering performance of the complete conceptual design and by identifying the required laser/pellet performance. The performance of the laser fusion hybrid has also been compared to a typical fast breeder reactor. The results show that the laser fusion hybrid produces enough fissile material to fuel more than six light water reactors (LWR's) of equivalent thermal power while operating in a regime which requires an order of magnitude less laser and pellet performance than pure laser fusion. In comparison to a fast breeder reactor the hybrid produces 10 times more fissile fuel. An economic analysis of the design shows that the cost of electricity in a combined hybrid-LWR scenario is insensitive to the capital cost of the hybrid, increasing by only 20 to 40 percent when the capital cost of the hybrid ranges from …

Paramagnetic ions in glass reside in a distribution of physically different environments. By using a tunable laser source, selected groups of ions within an inhomogeneously broadened absorption band are excited and line-narrowed fluorescence is observed. The technique of laser-induced fluorescence line narrowing has been applied to several rare-earth ions in glasses to investigate site-to-site variations in energy levels, probabilities for radiative and non-radiative transitions, homogeneous line broadening, and energy transfer between ions. Results and interpretations of these experiments are reviewed, and possible extensions of these techniques are discussed. 25 references, 3 fig.