An access system based on the one now in operation at the CERN ISR is recommended. Access doors would presumably be located at the entrances to the utility tunnels connecting the support buildings with the ring. Persons requesting access would insert an identity card into a scanner to activate the system. The request would be autologged, the keybank adjacent to the door would be unlocked and ISABELLE operations would be notified. The operator would then select the door, activating a TV-audio link. The person requesting entry would draw a key from the bank, show it and his film badge to the operator who would enable the door release.

The composition of a thorium metal surface has been monitored using Auger electron spectroscopy following Ar/sup +/ bombardment at different temperatures. After extended Ar/sup +/ bombardment, enough contaminated overlayers were removed to expose a surface region containing only thorium, bulk impurities, and imbedded argon. The main impurities, carbon and oxygen, differed in their behavior when the sample was annealed following bombardment. The amount of surface carbon either increased or remained constant during annealing depending upon the temperature of the sample during bombardment. The amount of surface oxygen decreased rapidly when the sample was heated above 500/sup 0/C regardless of the sample temperature during bombardment. These experiments indicate that preparation of clean, annealed thorium surfaces requires ion bombardment at temperatures > or = 400/sup 0/C.

The target chamber of a laser fusion reactor will contain small amounts of background gases. As the beam is focused, it ionizes the gas and Raman scattering is induced. Density limits on the background gas are found in order that the laser beam will not become appreciably decollimated. It is found that laser bandwidth efficiently decreases the scattering effect.

The use of a silver-zeolite halogen adsorber placed in series with a hydrogen catalytic recombiner and a cryogenic noble gas adsorber assembly constitutes a waste gas processing system (WGPS) capable of handling hydrogen and fission product gases following a Loss-of-Coolant Experiment (LOCE). This paper describes: the types and quantities of gases expected to be found at the facility after a failed-fuel LOCE; the purpose of the WGPS; and the general configuration and expected decontamination factors associated with the LOFT WGPS.

Methodology in use in the Imperial Valley for assessing the potential impact on air quality that may result from the development of geothermal resources is discussed. The installation of a network of air quality stations for characterizing the air quality and atmospheric transport properties in the valley prior to development is discussed. Analyses of geothermal fluids for various gases are performed to evaluate the potential emission rates from future geothermal power plants. The principal pollutant of concern is H/sub 2/S because of its noxious odor and potential release rate. These estimated source emission rates and the appropriate meteorological measurements are used as input to a three-dimensional, atmospheric transport code to estimate the potential changes in air quality that result from various scenarios for development of geothermal power.

The injector system for the Tandem Mirror Experiment (TMX) contains the components required to create and maintain a high-temperature, high-density plasma. These components include a streaming-plasma gun in each of the plug tanks to form the target-plasma, 24 neutral-beam source modules for injecting neutral deuterium atoms to heat and replace losses from the plasma, and a gas box system that applies a streaming cold gas to the plasma to stabilize it. This paper discusses the mechanical design problems and solutions for this injector system.

Liquid-nitrogen-cooled liners have been installed in the neutral-beam source tanks of 2XIIB. The installation has resulted in improvements in vacuum pumping, although testing is not complete. The liners are stainless-steel-flooded-type liners, using spot-welded-and-inflation construction. The natural-convection flow system must keep the liners cold during the high heat loads imposed during Ti gettering.

In the past few months, detailed experimental data have become available on laser light absorption versus angle, plasma density profiles near the critical surface, and stimulated scattering processes. In the light of these experiments, it seems timely to reassess our theoretical understanding of these phenomena. A quantitative comparison of the data with current results of plasma simulations and theory is presented and the areas where further theoretical effort is called for are pointed out. Three recent experiments done at Livermore are compared with the latest theoretical and simulation results on laser-plasma interactions. The analysis covers the following areas: (1) theory of resonance absorption on a rippled critical surface, compared with an experiment on the angle and polarization dependence of absorption; (2) theory of density profile steepening, compared with holographic interferometry measurements; and (3) theory of stimulated Brillouin scattering in long density gradients, compared with reflectivity measurements for long pulse, large focal spot experiments.

An extractor for accelerating 50 A of deuterium ions to 10 keV for injection into a metal-vapor charge-exchange cell has been designed. The beam-forming electrodes are convection cooled and capable of continuous service.

Recent experiments with high Z disks on the Argus facility have exteanded our knowledge of the temperature (inferred from the slope of the hard x-ray spectrum) of laser generated suprathermal electrons, from the previous regime of 1 less than or equal to Z less than or equal to 30 to the Z approx. = 80 regime. The systematic rise of temperature with Z is theoretically analyzed. We believe that material albedoes (electron reflectivity) which increase with Z can account for this behavior, since electrons can make multiple passes through the region of resonant electric fields and are thus reheated. We treat this effect quantitatively and obtain reasonable agreement with experiment. The effects of magnetic fields and filamentation are also examined.

The hazards associated with low-level radioactive waste, one of the nation's greatest concerns, are discussed from a health physicist's perspective. Potential biological hazards, four stages of the low-level radioactive waste disposal process, and suggested methods of reducing the risks of handling and disposal, based on previous studies, are defined. Also discussed are potential pathways of human exposure and two scenarios designed to demonstrate the complexity of modeling exposure pathways. The risks of developing a fatal cancer from exposure to the radioactive material, should it occur, is compared to other more commonly accepted risks.

In response to the increasing severity of target surface finish requirements for laser fusion experiments, it has become necessary to examine spherical targets in the Scanning Electron Microscope, prior to laser irradiation, on an orderly nondestructive basis. We have developed a new sample manipulation technique which rolls a thin wall sphere through 4..pi.. steradians, minimizes damage and allows easy recovery. The sphere is placed between two parallel plane surfaces formed in conductively coated silicone rubber on the ends of capillaries. Mechanical slides cause the capillaries to translate laterally and roll the ball bringing the entire surface of the sphere into a position for examination. Resolutions comparable with traditional mounting techniques are attained. A side looking, Si(Li) detector increases the utility of the system by allowing simultaneous energy dispersive x-ray microanalysis. The entire detector assembly slips between the secondary electron detector and the sphere rolling capillaries to collect x-rays from the target.

The rather extensive test program performed on the FFTF preheat control system resulted in successful sodium fill of one secondary heat transport loop on July 2, 1978. The data obtained during testing and the attendant operating experience gained resulted in some design changes and provided the information necessary to fully characterize system performance. Temperature excursions and deviations from preset limits of only a minor nature were encountered during preheat for sodium fill. The addition of the rate alarm feature was beneficial to operation of the preheat system and allowed early detection and correction of impending excursions.

Transport by groundwater is the most likely means of escape for radioactive waste contained in a geologic repository. The rock formations through which the groundwater flows are characterized by inhomogeneities on all distance scales. Large scale inhomogeneities cause pulses of dissolved pollutants to spread both in the direction of motion and transverse to it. This phenomenon is known as macroscopic dispersion. Similarly, inhomogeneities in the chemical properties of the rock will cause this spreading to be greater for species whose movement through the rock is retarded by waste rock chemical interactions. Previous risk analyses of nuclear waste disposal which have ignored macroscopic dispersion found that predicted radiation doses to individuals are very sensitive to the waste dissolution time. When macroscopic dispersion is incorporated into the analysis, however, the sensitivity of risk to dissolution time is greatly reduced. 6 figures, 2 tables.

A method for obtaining a constitutive relation that relates the flow stress to the equivalent plastic strain is developed. The method uses simple tension test data to suggest a functional form. This form is then used as a constitutive model in a computer program that simulates the tension test. The calculated results are compared with the experimental results and the functional form is refined until agreement is obtained between calculations and experiments. The importance of knowing the relationship between the flow stress and the plastic strain is discussed. A work hardening function is calibrated for 6061 T6 aluminum.

Recent experimental progress in the fields of photofission and electrofission of actinide nuclei is summarized. In particular, experimental results which throw light on the delineation of the characteristics of the giant resonances are highlighted. Measurements of especial interest in this regard include photofission cross-section studies with monoenergetic photons and electrofission yield and angular-distribution studies. 36 references.

The present calculations are applicable to any beam geometry with cylindrical symmetry, including the converging beam geometry (large entrance port with radius > or approx. = 10 cm), as well as the pencil-shaped beam (small porthole with radius approx. mm). The small porthole is clearly advantageous from the reactor vessel design point of view. While the physics of the latter mode of propagation may be more complex, analyses up to this point have not revealed any detrimental instability effects that will inhibit propagation. In fact, the large perpendicular velocity v/sub perpendicular/ that the pinched mode can accommodate provides a mechanism for the quenching of filamentary instability. Furthermore, this mode of propagation can withstand more ion scattering and is not subject to the upper bound on pressure (p < 10 torr) which is imposed on the converging beam mode.

Computations have been made of the parameters of a neutral-beam driven, field-reversed mirror reactor as a function of beam injection energy. Q values of 4 to 5 and a fusion power of 10 to 50 MW per cell are found at beam energies of 200 to 500 keV. Cost estimates indicate a direct capital cost of less than $1000/kW/sub e/ for multicell versions of the reactor.

Details of existing superconducting magnet failures are collected and evaluated with regard to future CTR superconducting magnet safety and reliability. Fourteen magnet systems with sixteen failures are presented. These failures are analyzed and categorized as to causative factors (e.g. hot spots, arcing, lead failures, and conductor movement). Responses of the instrumentation and protection systems during these accident situations are also presented. Repairs and present status of the magnets are described. Preliminary conclusions are: the failure rate of existing magnet systems is too high to be tolerable for CTR magnets; although failure analyses of present systems can be used as a reference for future CTR magnet safety design, the prediction of successful operation of CTR magnet systems represents a significant extrapolation from the experiences accumulated so far; much development work and repeated testing of magnet system components and sub-systems are required.

The light emission time response of quenched NElll plastic scintillators has been measured using a streak camera (20 ps resolution) and 100 to 180 ps, 1.06 ..mu..m, laser-produced, pulsed, low energy x-ray excitation. Each light output pulse was obtained by deconvolution from the film data using the x-ray temporal response measured with an x-ray sensitive streak camera (10 ps resolution). Time response parameters are presented for benzophenone and acetophenone, quenching agents which most effectively reduce the decay time of the singlet component. Full width-half-maximums less than or equal to 260 ps were observed for NElll samples quenched with greater than or equal to 2 percent benzophenone. Results are given for unquenched samples consisting of different concentrations of butyl-PBD in PVT and for the phosphor ZnO doped with Ga.

Analysis of the sensitivity of previous negative searches for magnetic monopoles shows that they constitute prior evidence against the monopole interpretation of the event reported as ''evidence for detection of a moving magnetic monopole''. The strength of the evidence varies with the unknown mass of the monopole. For M less than or equal to 10/sup 5/ GeV, odds are greater than 10/sup 6/ : 1 against. For larger masses, the limits depend strongly on assumptions about the range of monopoles and the threshold for detection of monopole tracks in obsidian. In no case are the odds, less than 8 : 1 and they may be no less than 8000 : 1 against. Since the reported event may also be due to an electrically charged heavy particle, it is probably not due to a monopole.

Construction has started on an outdoor testing station for flexible ac superconducting power transmission cables. It is intended to serve as an intermediate step between laboratory-scale experiments and qualification testing of prototype-scale cables. The permanent equipment includes a 500 W supercritical helium refrigerator using a screw compressor and multistage turbine expanders. Helium storage for 250,000 cu ft of helium at 250 psi is provided. Initially, the cables will be tested in a horizontal cryostat some 250 ft long. High-voltage 60 Hz tests will be performed with the cable in a series resonant mode with a maximum line to ground capability of 240 kV, this is adequate for a 138 kV system design. Impulse testing up to about 650 kV is planned. The cable conductor will be energized by current transformers, initially at about 4 kA and later up to fault levels of 40 kA. The refrigerator is now at the site and testing on a dummy load will commence in the Fall of 1976. The cryostat will be installed in 1977 followed about a year later by the first cable tests.

Results of recently concluded investigations of infrared laser induced photoionization of very high lying even parity levels in atomic uranium are presented. Behavior of both Rydberg and valence states is described.

Energy losses have been measured on a set of mixed matrix (CuNi, Cu, NbTi) superconducting wires at B's up to 1.5 x 10/sup 7/ G/s. The losses have been measured as a function of wire diameter, twist pitch, maximum applied field, and B. Both static and dynamic losses were measured for a field applied perpendicularly to the wire axis. The dynamic losses were measured by slowly applying an external field to a sample and then causing the field to decay exponentially in roughly 1 ms to 10 ms. Under low B (9 kG) and B (10/sup 6/ G/s) conditions the hysteretic loss dominated. At high B (21 kG) and B (1.5 x 10/sup 7/ G/s) the matrix losses became dominant. The systematic variation of the losses with the mentioned parameters will be presented and will be compared to theoretical predictions.