The basic operating characteristics of the Tandem Mirror Experiment, (TMX) at the Lawrence Livermore Laboratory in the USA have been established. Tandem-mirror plasmas have been produced using neutral-beam-fueled end plugs and a gas-fueled center cell. An axial potential well between the end plugs has been measured. There is direct evidence that this potential well enhances the axial confinement of the center-cell ions. The observed densities and loss currents are consistent with preliminary studies of the particle sources and losses near the magnetic axis. The observed confinement is consistent with theory when plasma fluctuations are low. When the requirement of drift-cyclotron loss-cone mode stability is violated, the plasma fluctuations degrade the center-cell confinement.

The rationale for hybrid fusion-fission reactors is the production of fissile fuel for fission reactors. A new class of reactor, the fission-suppressed hybrid promises unusually good safety features as well as the ability to support 25 light-water reactors of the same nuclear power rating, or even more high-conversion-ratio reactors such as the heavy-water type. One 4000-MW nuclear hybrid can produce 7200 kg of /sup 233/U per year. To obtain good economics, injector efficiency times plasma gain (eta/sub i/Q) should be greater than 2, the wall load should be greater than 1 MW.m/sup -2/, and the hybrid should cost less than 6 times the cost of a light-water reactor. Introduction rates for the fission-suppressed hybrid are usually rapid.

The development of hydrothermal energy for direct heat applications is being aided by twenty-two demonstration projects that are funded on a cost-sharing basis by the US Department of Energy, Division of Geothermal Energy. These projects are designed to demonstrate the technical and economic feasibility of the direct use of geothermal heat in the United States. Twelve of these projects are administered by the DOE-Idaho Operations Office with technical support from EG and G Idaho, Inc. Engineering and economic data for these projects are summarized in this paper. The data and experience being generated by these projects will be an important basis for future geothermal direct use projects.

The US Department of Energy (DOE) is involved in numerous geothermal research, development, demonstration, and loan guaranty projects in the State of California. These projects often require the preparation of both an Environmental Impact Report (EIR), as required by California Environmental Quality Act (CEQA), and an Environmental Assessment (EA) or Impact Statement (EIS) as required under NEPA. DOE adoption or utilization of information contained in EIR's to meet that agency's NEPA requirements and thereby reduce duplication of effort is dependent on four critical issues: (1) the scope of the proposed action analyzed, (2) the completeness of treatment of environmental issues, (3) the level of DOE involvement in EIR preparation, and (4) the timing of DOE involvement in EIR preparation. At this time, several constraints prevent the integration of the DOE Loan Guaranty and CEQA environmental review and documentation processes. First, the time required to complete an EIR (up to 2 years in some cases) is not compatible with DOE's goal of processing loan guaranty applications within a 4 month period. Second, the CEQA process is usually initiated and completed prior to DOE's involvement in the project. Therefore, DOE often has no role in document preparation and must verify the content …

The build-up and quasi-steady state phases of the operation of the tandem mirror experiment, TMX, and of a tandem mirror machine with inboard thermal barriers, MFTF-B, have been simulated using a fluid model of the central cell and plug plasmas. The fluid model incorporates classical radial transport, three-dimensional cold gas transport in cylindrical geometry, and neutral beam transport corrected for finite-Larmor-orbit effects in both the central cell and yin yang end plugs.

The purpose of this program is to provide employees with the motivation, knowledge and skills necessary to maintain ideal body weight throughout life. The target audience for this program, which is conducted in an industrial setting, is the employee 40 years of age or younger who is at or near his/her ideal body weight.

The Advanced Test Accelerator (ATA) is a pulsed linear induction accelerator with the following design parameters: 50 MeV, 10 kA, 70 ns, and 1 kHz in a ten-pulse burst. Acceleration is accomplished by means of 190 ferrite-loaded cells, each capable of maintaining a 250 kV voltage pulse for 70 ns across a 1-inch gap. The unique characteristic of this machine is its 1 kHz burst mode capability at very high currents. This paper dscribes the pulse power development program which used the Experimental Test Accelerator (ETA) technology as a starting base. Considerable changes have been made both electrically and mechanically in the pulse power components with special consideration being given to the design to achieve higher reliability. A prototype module which incorporates all the pulse power components has been built and tested for millions of shots. Prototype components and test results are described.

The development of hydrothermal energy for direct heat applications is being accelerated by twenty-two demonstration projects that are funded on a cost-sharing basis by the US Department of Energy, Division of Geothermal Energy. These projects are designed to demonstrate the technical and economic feasibility of the direct use of hydrothermal resources in the United States. Engineering and economic data for the projects are summarized. The data and experience being generated by these projects will serve as an important basis for future direct heat development.

A study was conducted to determine the effect of phantom size, shape and composition on the response of an albedo neutron dosimeter. The most important feature was the shape. The dose equivalent rate from a californium neutron source was determined. Ten different dose rates were determined which varied from 2.39 to 3.02 rem/h for the CF source used. (ACR)

An alloy of type 316 stainless steel with the addition of 0.23% Ti (316 + Ti) has been irradiated in the 20% cold-worked condition in the HFIR (a mixed fast and thermal neutron spectrum reactor) and tested near the irradiation temperature in the range of 300 to 600/sup 0/C. Tensile tests were performed following irradiation to fluence levels of 0.63 to 2.1 x 10/sup 26/ n/m/sup 2/ (E > 0.1 MeV) and helium levels of 200 to 1000 at. ppM. The 316 + Ti exhibited higher strength and lower ductility than similarly irradiated type 316 stainless steel (316 SS). However, the tensile elongation of 316 + Ti tends to saturate with increasing fluence at 575/sup 0/C whereas the elongation of 316 SS continues to fall for the fluences investigated. Reduction of area is similar for the two alloys, and 316 + Ti shows completely ductile rupture at 450/sup 0/C and below. The differences in strength and ductility are attributed to the influence of TiC precipitates trapping helium in the matrix.

Fabrication of Inertial Confinement Fusion (ICF) targets requires deposition of various types of coatings on microspheres. The mechanical strength, and surface finish of the coatings are of concern in ICF experiments. The tensile strength of coatings can be controlled through grain refinement, selective doping and alloy formation. We have constructed a magnetron co-sputtering system to produce variable density profile coatings with high tensile strength on microspheres.

Core snubbers, located near the neutral beam source ends of the Mirror Fusion Test Facility (MFTF) Sustaining Neutral Beam Power Supply System (SNBPSS) source cables, protect the neutral beam source extractor grid wires from overheating and sputtering during internal sparkdowns. The snubbers work by producing an induced counter-emf which limits the fault current and by absorbing the capacitive energy stored on the 80 kV source cables and power supplies. A computer program STACAL was used in snubber magnetic design to choose appropriate tape wound cores to provide 400 ..cap omega.. resistance and 25 J energy absorption. The cores are mounted horizontally in a dielectric structure. The central source cable bundle passes through the snubber and terminates on three copper buses. Multilam receptacles on the buses connect to the source module jumper cables. Corona rings and shields limit electric field stresses to allow close clearances between snubbers. A filament circuit shunt bias winding wound on a dielectric cylinder surrounds the cores. The dc voltage holdoff of a single snubber has been tested. Current and voltage behavior during capacitor bank and source cable discharges are presented.

Heat is radiated from both the vacuum vessel that houses the magnet and the heated plasma that exists at the central region of the magnets. Approximately 30 kW of heat will be transmitted to the 311 m/sup 2/ of magnet surface area from these two heat sources. We can reduce this heat load substantially by installing liquid nitrogen (LN)-filled panels around the magnets to counteract the 300/sup 0/K vessel wall temperature. When flowing the LN inside the panels, the temperature drops to 85/sup 0/K. These LN panels also serve as thermal protection for the helium pipings in the MFTF magnet system. However, near the plasma where a higher heat load is generated, we must add water panels to protect the LN panels. All the LN panels, water panels, and their manifoldings are called the magnet liners. Of the total of 344 pieces, 240 are used directly on the magnets. The support system that mounts these LN liner panels on the magnets is the topic of this paper.

A conceptual design study of a large 12-T yin-yang pair of coils, typical of the plug coils envisioned for a tandem-mirror facility to follow MFTF, has been completed. Because of its larger size and field strength, the magnetic forces are much greater than those experienced on MFTF. The main purpose of this study, therefore, is to assess the feasibility of such a device, paying particular attention to mechanical stress and conductor strain. The conductor proposed operates at 15.6 kA and consists of a rectangular half-hard copper stabilizer with a Nb-Ti insert in the low-field regions and Nb/sub 3/Sn in the high field. The coil is divided into four sections in the longitudinal direction, with steel substructure to limit the winding stress to an acceptable level. The conductor is cryostatically stabilized in superfluid He at 1.8K and 1.2 atm, with an operating heat flux of 0.8 W.cm/sup -2/.

The conductor development and the magnet design and construction for the MFTF are described. Future plans for the Mirror Program and their influence on the associated superconductor development program are discussed. Included is a summary of the progress being made to develop large, high-field, multifilamentary Nb/sub 3/Sn superconductors and the feasibility of building a 12-T yin-yang set of coils for the machine to follow MFTF. In a further look into the future, possible magnetic configurations and requirements for mirror reactors are surveyed.

In our quest to understand radiation damage in materials, it is vital that we characterize radiation sources in terms of neutron flux and spectra as well as the more-fundamental displacement damage, gas production, and transmutation rates. Such data are crucial to correlations of materials-property changes in different environments and to predictions of materials performance in inaccessible environments, such as fusion reactors. Dosimetry techniques have been developed to measure the neutron flux and spectra in diverse facilities including thermal, fast, and mixed reactors, T (d,n) and Be (d,n) accelerator sources, and high-energy spallation sources. Displacement-damage cross sections have been calculated for 36 elements spanning the periodic table. All of these exposure parameters can now be routinely measured with 10 to 15% relative accuracy at all existing radiation-effect facilities. 4 tables.

Fabrication of Inertial Confinement Fusion (ICF) targets requires deposition of various types of coatings on microspheres. The mechanical strength, and surface finish of the coatings are of concern in ICF experiments. The tensile strength of coatings can be controlled through grain refinement, selective doping and alloy formation. We have constructed a magnetron co-sputtering system to produce variable density profile coatings with high tensile strength on microspheres. The preliminary data on the properties of a Au-Cu binary alloy system by SEM and STEM analysis is presented.

We discuss the evolution of the tandem mirror reactor concept from the original conceptual reactor design (1977) through the first application of the thermal barrier concept to a reactor design (1979) to the beginning of the Mirror Advanced Reactor Study (1982).

Inertial-fusion targets were designed for use with heavy-ion accelerators as drivers in fusion energy power plants. In the interest of providing inputs for understanding the trade-offs among accelerator designs, an initial survey was carried out regarding target gain versus parameters of relevance. This was done in two stages, firstly target gain was related to the beam energy, power, focal radius, and ion range. Secondly, a more comprehensive discussion was made by posing target gain constraints on the beam-occupied phase-space volume of the linacs. This latter discussion had included some rather simplified models of accelerator final focus and beam transport in near-vacuum fusion reaction chambers. Some further analyses of the basic assumptions of this summary are also described.

We have been studying small, driven fusion reactors as candidates for a Technology Development Facility (TDF) to be used for testing reactor subsystems, components, and materials. Magnetic mirror systems are particularly interesting for this application because of their inherent steady-state operation, potentially high wall loading, and relatively small size. The systems so far studied have 14-MeV neutron wall loads ranging from 1 to 3 MW m/sup -2/ on testing surface areas of 2 to 5 m/sup 2/ with annual fluences as high as 10/sup 21/ neutrons cm/sup -2/. These devices are based on physics and engineering that has been demonstrated or is scheduled for demonstration in the next year.

Airborne temperature surveys were used to depict the small surface temperature differences related to heat flow anomalies. Zones with conductive heat flow differences of 45 +- 16 ..mu..cal/cm/sup 2/(s) had predawn surface temperature differences of 1.4 +- 0.3/sup 0/C. Airborne temperature surveys were coordinated with field temperature surveys at Long Valley, California, the site of a known geothermal resource area. The airborne temperature surveys recorded redundant, predawn temperatures at two wavelengths and at two elevations. Overall temperature corrections were determined by calibrating dry soil surface temperatures with thermistor probes. The probes measured air and soil temperatures within 2 cm of the surface, every twenty minutes, during the survey overflights.

One of the more intriguing phenomena discovered in heavy-ion physics is the seeming appearance of high energy structure in the excitation spectra of inelastically scattered heavy ions. For reasons illustrated, these may well be a phenomena unique to heavy ions and their explanation perhaps unique to TDHF.

Chairman William Ogle said the overall purpose of the meeting was to consider how the US government, and the Division of Geothermal Energy in particular, might apply its geothermal effort more effectively. Given the present situation, how does Uncle Sam make the best possible effort? On this theme, there are 4 main subquestions: (1) what government support is needed? (2) how can we improve cooperation between industry, the national laboratories, universities, and industries, and does it matter? (3) how do we transfer technology to industry? (4) What should the technical aims be for the next year or so?

As part of technical assistance to the US Nuclear Regulatory Commission (NRC, 1), a systematic format for seismic equipment qualification (EQ) was initiated. This format consists of thirty issues associated with seismic EQ. Each issue was considered as a Category of Possible Seismic EQ Requirements and Criteria. That is, seismic EQ standards might be (but presently are not formulated in terms of requirements and criteria that address each of the thirty issues. Each of the thirty issues was ranked and a minimum set identified. The current requirements in existing NRC and national standards were also evaluated against this common set of issues, and they were estimated to score 60 out of 100 overall. It is believed that the systematic format exhibited in this paper can be of assistance in obtaining a broader and more complete perspective on seismic EQ issues. This format (but especially the technique) may also be of interest in non-seismic EQ since many of the issues are common.