Separate abstracts were prepared for the papers presented in the subject area: hydrogen sources and detection.

This paper describes a maintenance problem in a fusion power plant. The problem is to specify which life limited parts should be replaced when there is an opportunity. The objective is to minimize the cost rate of replacement parts and of maintenance actions while satisfying a power plant availability constraint. The maintenance policy is to look ahead and replace all parts that will reach their life limits within a time called a screen. Longer screens yield greater system availabilities because more parts are replaced prior to their life limits.

A distributed microprocessor control and data acquisition network has been designed for implementation on the Lawrence Livermore National Laboratory 100 MeV electron/positron accelerator (LINAC). The system has been designed to be as transparent to the user as possible by stressing responsiveness, reliability, and relevance of data presented to the user. Implementation of the network will take place in modular fashion in three stages, so as to minimize disruption of normal operations. The first elements to be installed will be the beam transport system controls, beam set-up time. Beam diagnostic equipment is now being position monitors, and accelerator operating status monitors. These units will reduce beam set-up time. Beam diagnostic equipment is now being designed that will be used in a second stage implementation. This stage will concentrate on determining beam parameters and allowing the user to optimize the beam for a given parameter. The final stage will be to install experimenter data acquisition equipment. The equipment will augment the presently existing data acquisition system. The completed network will allow a more efficient operation of the LINAC, resulting in reduced experiment costs, and more controllable beam parameters, both of which are major concerns of experimenters.

This paper describes recent experience in re-evaluating the dose to an employee. This employee was plagued with skin disorders for years, but he questioned his recorded beta dose only after a recent LLNL cancer study began collecting data. He was concerned that his radiation dose recorded during the time he worked on a fission burst reactor experiment in 1963 did not represent the actual dose he received. About six months were spent gathering information, putting the information together, making necessary calculations, and reaching a reasonable result (a reasonable result being one for which the known information fits the calculated results with a minimum of inconsistencies). This paper presents the beta and gamma whole-body and hand radiation dose calculations, and compares these calculated dose rates with the meter, film, and pocket dosimeter information recorded in the health and safety log, operation log, and dosimetry record.

Studies are currently being made to design an axisymmetric modification to the TMX-Upgrade experiment. The existing TMX-Upgrade quadrupole plug and transition magnet sets are replaced by the circular coils of an axisymmetric plug. The existing TMX-Upgrade magnet set is shown. The circular coils are sectioned to show the quadrupole magnets and the flux bundle. The two end cells of this magnet set are MHD stable minimum-B plugs. From a mechanical design viewpoint, an axisymmetric design is attractively simple. One of the axisymmetric designs under consideration is the Modified Cusp. A magnet set for this designs is shown. The coils are sectioned to show their cross-section.

Cryosorption vacuum pumps continue to be the principal type of pumping systems considered for power-producing fusion reactors. In this context, a compound-pump concept is generally employed in which the helium pump is placed behind the hydrogen pump so that hydrogen will not condense on and hence block the 4.2 K helium cryosorption surface. To obtain an optimal design for such a pump, the amount of hydrogen which can reach the helium panel has been determined. Catastrophic failure of a cryosorption pump was observed in previous work when a 95% hydrogen-5% helium mixture was tested. No such failure has occurred in our studies with 4, 10, and 20% hydrogen. However, significant changes in pumping speed have been noted when only 4% hydrogen is present. Both helium and hydrogen speeds are reduced to approximately one-half to one-third of the pure compound speed. Many of the qualitative aspects of the behavior of the pump for pure helium are also observed for the hydrogen-helium mixtures. Cyclic variation in pumping speed above a helium feed rate of approx. 6 x 10/sup -6/ torr-L/s.cm/sup 2/ is one such similarity; however, at the 4% hydrogen level, the period between instabilities is longer for the mixtures.

The evolution of magnetized neutron stars with field strengths of approx. 10/sup 12/ gauss that are accreting mass onto kilometer-sized polar regions at a rate of approx. /sup 13/ M/sub 0/yr/sup -1/ is examined. Based on the results of one-dimensional calculations, one finds that stable hydrogen burning, mediated by the hot CNO-cycle, will lead to a critical helium mass in the range 10/sup 20/ to 10/sup 22/ g km/sup -2/. Owing to the extreme degeneracy of the electron gas providing pressure support, helium burning occurs as a violent thermonuclear runaway which may propagate either as a convective deflagration (Type I burst) or as a detonation wave (Type II burst). Complete combustion of helium into /sup 56/Ni releases from 10/sup 38/ to 10/sup 40/ erg km/sup -2/ and pushes hot plasma with ..beta.. > 1 above the surface of the neutron star. Rapid expansion of the plasma channels a substantial fraction of the explosion energy into magnetic field stress. Spectral properties are expected to be complex with emission from both thermal and non-thermal processes. The hard ..gamma..-outburst of several seconds softens as the event proceeds and is followed by a period, typically of several minutes duration, of softer x-ray emission as …

The Tandem Mirror Experiment-Upgrade (TMX-Upgrade) construction will be completed in 18 months at a total cost of $14.5 million. This paper describes the project planning and the management techniques used to complete the TMX-Upgrade within its allocated cost and schedule. In the planning stages of a project, before approval of the proposal, we define major project objectives, create a work breakdown structure (WBS), detail a technical description for each level of the WBS, and provide detailed bottoms-up cost estimates and summary schedules. In the operating phase, which continues throughout the project, we establish budget and schedule baselines. The reporting phase includes The Department of Energy (DOE) reviews of project status at monthly, quarterly, and semiannual intervals. These reports include cost, schedule, manpower, major procurement, and technical status information.

Inertial-fusion targets have been designed for use with heavy-ion accelerators as drivers in fusion energy power plants. We have made an initial survey of target gain versus beam energy, power, focal radius, and ion range. This provides input for understanding the trade-offs among accelerator designs.

We present results and analysis for laser-irradiations of Be, CH, Ti, and Au disk targets with 0.53 ..mu..m light in 3 to 35 J, 600 ps pulses, at nominal intensities from 3 x 10/sup 13/ to approx. 4 x 10/sup 15/ W/cm/sup 2/. The measured absorptions are higher than observed in similar 1.06 ..mu..m irradiations, and are largely consistent with modeling which shows the importance of inverse bremsstrahlung and Brillouin scattering. Observed red-shifted back-reflected light shows that Brillouin is operating at low to moderate levels. The measured fluxes of multi-keV x-rays indicate low hot-electron fractions, with temperatures which are consistent with resonance absorption. Measurements show efficient conversion of absorbed light into sub-keV x-rays, with time-, angular-, and spatial-emission distributions which are generally consistent with non-LTE modeling using inhibited thermal electron transport.

Recent studies at Lawrence Livermore National Laboratory (LLNL) with a bounce-averaged Fokker-Planck code indicate that the energetic electron tail formed by electron-cyclotron resonant heating (ECRH) at the second harmonic is not Maxwellian. We present the results of our bounce-averaged Fokker-Planck code along with some simple analytic models of hot-electron distribution functions.

Chemical decomposition models have been deduced from the available chemical kinetic data on the thermal decomposition of HMX, TATB, RDX, and TNT. A thermal conduction model is used in which the thermal conductivity of the reacting explosive decreases linearly with the mass fraction reacted to that of the gaseous products. These reactive heat flow models are used to predict the time to explosion versus reciprocal temperature curves from several heavily confined explosive tests. Good agreement is obtained between experimental and calculated explosion times for the pure explosives HMX, TATB, RDX, and TNT, mixtures such as RX-26-AF (HMX/TATB), Octol (HMX/TNT), and Comp B (RDX/TNT), and for PBX 9404, an HMX-based explosive containing an energetic nitrocellulose binder.

Three models have been developed to estimate the effects of air pollutants on vegetation at the photosynthetic process (PHOTO), plant (GROWl), and community (SILVA) levels of resolution. PHOTO simulates the enhancement of photosynthesis at low H/sub 2/S levels, depression of photosynthesis at high H/sub 2/S levels, and the threshold effects for sulfur pollutants. GROWl simulates the growth and development of a plant during a growing season. GROWl has been used to assess the effects on sugar beets of geothermal energy development in the Imperial Valley, California. SILVA is a community-level model simulating the effects of SO/sub 2/ on growth, species composition, and succession, for the mixed conifer forest types of the Sierra Nevada, California.