A technique for modeling quasiparticle excitation energies and rotational parameters in odd-odd deformed nuclei has been used to construct sets of discrete states with energy 0 to 1.5 MeV in /sup 176/Lu and /sup 236/Np. These data were used as part of the input for calculation of isomer production cross-section ratios in the /sup 175/Lu(n,..gamma..)/sup 176/Lu and /sup 237/Np(n,2n)/sup 236/Np reactions. In order to achieve agreement with experiment, it has been found necessary to include in the modeled set many rotational bands (35 to 95), which are comprised of hundreds of levels with their gamma-ray branching ratios. It is essential that enough bands be included to produce a representative selection of K quantum numbers in the de-excitation cascade. 20 refs., 3 figs., 3 tabs.

Isomer ratio calculations were made for the reactions: /sup 175/Lu(n,..gamma..)/sup 176m,g/Lu, /sup 175/Lu(n,2n)/sup 174m,g/Lu, /sup 237/Np(n,2n)/sup 236m,g/Np, /sup 241/Am(n,..gamma..)/sup 242m,g/Am, and /sup 243/Am(n,..gamma..)/sup 244m,g/Am using modeled level structures in the deformed, odd-odd product nuclei. The hundreds of discrete levels and their gamma-ray branching ratios provided by the modeling are necessary to achieve agreement with experiment. Many rotational bands must be included in order to obtain a sufficiently representative selection of K quantum numbers. The levels of each band must be extended to appropriately high values of angular momentum.

We have derived absolute dipole strength-function information for /sup 176/Lu from an average resonance capture study of /sup 175/Lu with 2-keV neutrons and from neutron capture cross-section measurements with neutrons from 30 keV to about 1 MeV. We found that we needed to increase our previous estimate of the relative M1/E1 strengths near 5 MeV by a factor of 3 and to revise downward the absolute magnitude of our E1 strength function. We accomplished the latter, while still maintaining continuity with the photonuclear data, by adjusting the one free parameter in our line shape. The present E1 and M1 strengths now seem correct both near the neutron separation energy and also around 1 MeV.

The data for negative ion reflection yields is analyzed using a backscattering model for the secondary emission coefficient. The enhancement of the secondary emission coefficient is discussed in terms of reflection, formation, and survival probabilities. The yield of negative ions from alkali/transition metal surfaces by low energy atoms emitted from the ion-source discharge is calculated. Volume production of negative ions generated by plasma-surface interactions in a low-work-function-surface bucket-discharge is discussed.

A key objective of the US Inertial Confinement Fusion Program is to obtain high yield (100-1000 MJ) implosions in a laboratory environment. This requires high grain from an inertial fusion target from a driver capable of delivering about 10 MJ. Recent results have been sufficiently encouraging that the US Department of Energy is planning for such a capability called the Laboratory Microfusion Facility (LMF). In the past two years, we have conducted implosion-related experiments with approximately 20 kJ of 0.35-{mu}m laser light in 1-ns temporally flat-topped pulses. These experiments were done with the Nova laser, the primary US facility devoted to radiatively driven inertial confinement fusion. Our results show that we can accurately model a significant fraction of the phenomena required to obtain the fuel conditions needed for high gain. Both the x-ray conversion efficiency and the growth of Rayleigh-Taylor hydrodynamic instabilities are shown to be at acceptable levels. Targets designed so that the shape of the stagnated fuel can be imaged show that the x-ray drive in our hohlraums can be made isotropic to better than 3%. With this optimized drive and temporally unshaped laser pulses many critical implosion parameters are measured on targets designed for higher density. Good …

We have measured relative line intensities of the K x-ray spectra of Si, Cl, and Ca from laser-produced plasmas to assess their usefulness as a plasma diagnostic. The different elements are added at low concentrations to CH disks which are irradiated at 5 x 10/sup 14/ W/cm/sup 2/ with a 0.53 ..mu..m laser pulse of 20 Joules at 1 nsec. The concentration of each element is kept low in order not to change the Z of the plasma, and therefore the plasma dynamics. The various spectra are measured with a time-resolved spectrograph to obtain line intensities as a function of time over the length of the laser pulse. These relative intensities of various He-like and H-like lines are compared with calculations from a steady-state level population code. The results give good consistency among the various line ratios. Agreement is not as good for analysis of the Li-like satellite lines. Modelling of the Li-like lines need further investigation. 10 references, 9 figures.

The International Atomic Energy Agency is preparing a Safety Series publication on practical approaches for evaluating the reliability of the predictions made by environmental radiological assessment models. This publication identifies factors that affect the reliability of these predictions and discusses methods for quantifying uncertainty. Emphasis is placed on understanding the quantity of interest specified by the assessment question and distinguishing between stochastic variability and lack of knowledge about either the true value or the true distribution of values for quantity of interest. Among the many approaches discussed, model testing using independent data sets (model validation) is considered the best method for evaluating the accuracy in model predictions. Analytical and numerical methods for propagating the uncertainties in model parameters are presented and the strengths and weaknesses of model intercomparison exercises are also discussed. It is recognized that subjective judgment is employed throughout the entire modelling process, and quantitative reliability statements must be subjectively obtained when models are applied to different situations from those under which they have been tested. (6 refs.)

In order to anticipate problems from the radioactivation of neutral beam sources as a result of testing, a code has been developed which calculates both the radioactivities produced and the dose rates resulting therefrom. The code ACDOS2 requires neutron source strength and spectral distribution as input, or alternately, the source strength can be calculated internally from an input of neutral beam source parameters. A variety of simple geometries can be specified, and up to 12 times of interest following the shutdown of the neutron source. Radiation attenuating and daughter radioactivities are treated accurately. ACDOS2 is also of use for neutron-induced radioactivation problems involving accelerators, fusion reactors, or fission reactors.

For heating plasmas and for current drive in some fusion reactors, high energy neutral beams may be required. The high neutralization efficiency of H/sup -/ or D/sup -/ ions makes them favorable to form neutral atoms with energies in excess of 160 keV. It has been shown that a steady-state H/sup -/ ion beam with current greater than 1 A can be generated by a surface conversion type source with Mo being used as the converter material. In order to achieve the proper cesium coverage and thereby increasing the H/sup -/ ion yield, the application of porous cesium-dispensing converters is being investigated. It is also possible to optimize the H/sup -/ production by choosing the proper converter material. In this paper, we compare the negative ion yield generated by different materials (such as Mo, Ti, V, Nb, Pt, Pd, Rh, Cu, Ta, Al, Au, LaB/sub 6/ and stainless-steel) in the pure hydrogen and cesium-hydrogen modes of operation.

Volume-produced H/sup -/ ions have been extracted from a multi-cusp ion source by using a standard extraction system. In addition, a molybdenum converter is installed in the source to generate surface-produced H/sup -/ ions. The H/sup -/ ion yield is measured by a mass spectrometer. Without cesium, the production of H/sup -/ ions by the surface process is very small compared with those generated by volume production. However, the presence of cesium can greatly enhance the surface production yield. The energy spectrum shows that the surface-generated H/sup -/ ions contain two distinct groups when cesium is added to the discharge. The energy of one group is essentially that of the sheath potential and appears to be produced by a desorption process. The second group of H/sup -/ ions have slightly higher energies and appear to be formed by a reflection process. Different types of converter materials have also been tested.

Analysis of recent conceptual designs reveals that commercial fusion power systems will raise issues of occupational and public health and safety. This paper focuses on radioactive wastes from fusion reactor materials activated by neutrons. The analysis shows that different selections of materials and neutronic designs can make differences in orders-of-magnitude of the kinds and amounts of radioactivity to be expected. By careful and early evaluation of the impacts of the selections on waste management, designers can produce fusion power systems with radiation from waste well below today's limits for occupational and public health and safety.

Article discussing M-shell x-ray-production cross sections in thin targets of ₇₉Au, ₈₂Pb, ₈₃Bi, and ₉₂U by 0.3 - 2.6-MeV ₁⁴H+ and ₂⁴He+ ions.

Before small-angle neutron scattering (SANS), chain conformation studies were limited to light and small angle x-ray scattering techniques, usually in dilute solution. SANS from blends of normal and labeled molecules could give direct information on chain conformation in bulk polymers. Water-soluble polymers may be examined in H/sub 2/O/D/sub 2/O mixtures using contrast variation methods to provide further information on polymer structure. This paper reviews some of the information provided by this technique using examples of experiments performed at the National Center for Small-Angle Scattering Research (NCSASR).

Although it has been recognized for some time that the rate of reactive uptake of gases in cloudwater can depend on the value of the mass-accommodation coefficient (..cap alpha..) describing interfacial mass transport (MT), definitive evaluation of such rates is only now becoming possible with the availability of measurements of ..cap alpha.. for gases of atmospheric interest at air-water interfaces. Examination of MT limitation to the rate of in-cloud aqueous-phase oxidation of SO/sub 2/ by O/sub 3/ and H/sub 2/O/sub 2/ shows that despite the low value of ..cap alpha../sub O3/ (5 /times/ 10/sup /minus/4/), interfacial MT of this species is not limiting under essentially all conditions of interest; the high values of ..cap alpha.. for SO/sub 2/ (greater than or equal to 0.2) and H/sub 2/O/sub 2/ (greater than or equal to 0.08) indicate no interfacial MT limitation for these species also. Although gas- and aqueous-phase MT can be limiting under certain extremes of conditions, treating the system as under chemical kinetic control is generally an excellent approximation. Interfacial MT limitation also is found not to hinder the rate of H/sub 2/O/sub 2/ formation by aqueous-phase disproportionation of HO/sub 2/. Finally, the rapid uptake of N/sub 2/O/sub 5/ by …

Article discussing research on L- and M-shell x-ray production cross sections of Nd, Gd, Ho, Yb, Au, and Pb by 25-MeV carbon and 32-MeV oxygen ions.

Some data sets dealing with the hazards of low-level radiation are discussed. It is concluded that none of these reports, individually or collectively, changes appreciably or even significantly the evaluations of possible low-level radiation effects that have been made by several authoritative national and international groups. (ACR)

Three basic comparisons can be made between weapon system development and energy system development in the US--driving factors, system lifetime, and development time. Weapon system development and response is determined by a perceived threat to national security. Because the threat can change radically in this high technology atmosphere, weapon systems are usually designed for a 5 to 20 year lifetime. Development time from idea to capability is about 20 years on the average. In contrast, energy system development has been influenced by economics--demand, supply, return on investment--until the recent threat created by our dependence on oil. Energy systems are expected to operate 20 to 50 years and even longer. Development time is correspondingly long, i.e., 40 years from idea to large-scale use. The US needs to adopt a ''defense-oriented'' approach to protect its threatened energy security. Geothermal energy from hot dry rock is a new concept. The Hot Dry Rock Program is designed to minimize development time and may become a prime example of how a recognized threat to energy security can be answered by combined government/industry effort.

This report includes the Roster of registered Architects as of October 1980.

The Office of Energy Research was recently asked to perform a study of Large Scale Systems in order to facilitate the development of a true large systems theory. It was decided to ask experts in the fields of electrical engineering, chemical engineering and manufacturing/operations research for their ideas concerning large scale systems research. The author was asked to distribute a questionnaire among these experts to find out their opinions concerning recent accomplishments and future research directions in large scale systems research. He was also requested to convene a conference which included three experts in each area as panel members to discuss the general area of large scale systems research. The conference was held on March 26--27, 1984 in Pittsburgh with nine panel members, and 15 other attendees. The present report is a summary of the ideas presented and the recommendations proposed by the attendees.

This volume contains the written proceedings of the Symposium on High Temperature and Materials Chemistry held in Berkeley, California on October 24--25, 1989. The Symposium was sponsored by the Materials and Chemical Sciences Division of Lawrence Berkeley Laboratory and by the College of Chemistry of the University of California at Berkeley to discuss directions, trends, and accomplishments in the field of high temperature and materials chemistry. Its purpose was to provide a snapshot of high temperature and materials chemistry and, in so doing, to define status and directions.

This report contains short papers and abstracts on the following main topics: Ion-atom collision theory; laser physics; spectroscopy of atoms; spectroscopy of ions; and high velocity collisions.