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.

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.

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.

Detailed neutronics and photonics calculations have been performed for analyzing prompt and residual radiations and required shielding associated with the design of a laser-fusion facility with a nominal yield of 10/sup 19/ neutrons per D--T burn pulse. The standard Livermore Monte Carlo codes and nuclear data cross section libraries were used in calculations. The Bateman equation was used to calculate the accumulation and decay of radionuclide chain products. A number of activation sensitivity experiments were conducted and the results were found to be in very good agreement within 10 percent of those calculated. It has been found that neutron yields of 2 x 10/sup 19/ per day can be conducted continuously if the reactor chamber is Kevlar-epoxy or silica, the primary shield is 0.60-m of water immediately on the chamber, and the building concrete is 1.80 m thick. These precautions result in dose equivalents below the primary protection limits inside the target room after a few hours of cool-down per each 10/sup 19/ pulse, 10 percent of the primary protection limits immediately outside the target room, and 1 percent of the natural background level at the nearest site boundary.

The following are described: oscillator/preamp alignment; chain input pointing; spatial filter pinhole alignment; output pointing, focusing, and centering system; and alignment controls. (MHR)

The Imperial Valley is a 2,000-km/sup 2/ agricultural region in Southern California with annual crop values of more than $500 million. Geothermal reserves estimated at 130 GWe-yrs were found beneath this Valley. Development of that geothermal energy should occur in the next 10 to 20 years. To ensure that development is carried out in an environmentally sound manner, Lawrence Livermore Laboratory is engaged in a 3-yr study of the environmental effects that development of geothermal power production may have on the Imperial Valley. Preliminary work is described for a computer-modeling study to determine effects of such activity in one region of the Valley upon water quality in domestic artesian water wells in an area downstream from geothermal wells. Various models are considered to estimate contaminant concentration and transport dynamics and to design optimal monitoring systems for pollution surveillance of those domestic water wells.

As a mirror fusion facility, the Tandem Mirror Experiment (TMX) at the Lawrence Livermore Laboratory (LLL) is both new and different. It utilizes over 23,000 ft/sup 2/ of work area in three buildings and consumes over 14 kWh of energy with each shot. As a systems design, the facility is broken into discreet functional regions. Among them are a mechanical vacuum pumping system, a liquid-nitrogen system, neutral-beam and magnet power supplies, tiered structures to support these supplies, a neutron-shielded vacuum vessel, a control area, and a diagnostics area. Constraints of space, time, and cost have all affected the design.