From international conference on bone mineral measurement; Chicago, Illinois, USA (12 Oct 1973). Abstracts of papers presented at the international conference on bone mineral measurement are presented. The papers were grouped into two sessions: a physical session including papers on measuring techniques, errors, interpretation and correlations, dual photon techniques, and data handling and exchange; a biomedical session including papers on bone disease, osteoporosis, normative data, non-disease influences, renal, and activity and inactivity. (ERB)

None

The solution of a generalized Langevin equation is referred to as a stochastic process. If the external forcing function is Gaussian white noise, the forward Kolmogarov equation yields the transition probability density function. Nonlinear problems must be handled by approximation procedures e.g., perturbation theories, eigenfunction expansions, and nonlinear optimization procedures. After some comments on the first two of these, attention is directed to the third, and the method of statistical linearization is used to demonstrate a relation to the former two. Nonlinear stochastic systems exhibiting sustained or forced oscillations and the centered nonlinear Schroedinger equation in the presence of Gaussian white noise excitation are considered as examples. 5 figures, 2 tables. (RWR)

Under sponsorship of the Division of Applied Technology of AEC, Los Alamos Scientific Laboratory is investigating the possibilities and problems of extracting energy from geothermal reservoirs which do not spontaneously yield useful amounts of steam or hot water. The system for accomplishing this which is being developed first is a pressurized-water circulation loop intended for use in relatively impermeable hot rock. It will consist of two holes connected through the hot rock by a very large hydraulic fracture and connected at the surface through the primary heat exchanger of an energy utilization system. Preliminary experiments in a hole 2576 ft (0.7852 km) deep, extending about 470 ft (143 m) into the Precambrian basement rock underlying the Jemez Plateau of north-central New Mexico, revealed no unexpected difficulties in drilling or hydraulically fracturing such rock at a temperature of approximately 100 C, and demonstrated a permeability low enough so that it appeared probable that pressurized water could be contained by the basement rock. Similar experiments are in progress in a second hole, now 6701 ft (2.043 km) deep, about 1.5 miles (2.4km ) south of the first one. Here the bottomhole temperature is about 146 C, and again no unexpected difficulty was …

Some initial experiments are described which form part of a new program aimed at significantly extending the range of high pressures and densities which may be explored in laboratory equation-of-state (EOS) experiments. These experiments will utilize high-energy lasers, such as those employed in the Laser Fusion Program at Lawrence Livermore Laboratory (LLL), to generate intense shock waves in materials of interest.

Atomics International and Lawrence Livermore Laboratory are involved in the conceptual design of a laser fusion power plant incorporating the lithium fall target chamber. In this paper we discuss some of the more important design considerations for the target chamber and evaluate its nuclear performance. Sizing and configuration of the fall, hydraulic effects, and mechanical design considerations are addressed. The nuclear aspects examined include tritium breeding, energy deposition, and radiation damage.

The Climax stock at NTS was the site of weapons effects tests and is to be used for radwaste disposal studies. The layout of Climax and proposed experiments is illustrated. Geology of Climax is described briefly. Thermal tests showed the thermal conductivity to be essentially isotropic, only slightly temperature-dependent, and 3.0 W/m-/sup 0/K. Permeability is less than 1 nanodarcy. Plans for a spent fuel storage test and for rock mechanics tests are described. (DLC)

High Z discs have been irradiated with 1.06 ..mu.. laser light at intensities between 7 x 10/sup 13/ and 3 x 10/sup 15/ W/cm, and pulse lengths between 200 and 1000 ps. Due to the high Z, inverse bremsstrahlung becomes an important absorption effect and competes strongly with resonance absorption and stimulated scattering. We find that inhibited electron thermal conduction and non-LTE ionization physics are important. Their inclusion in the LASNEX modeling results in steepened temperature and density profiles near critical, thus producing a several keV underdense corona. These conditions bring what would otherwise be 100% inverse bremsstrahlung absorption down to the experimentally observed values (50% at 10/sup 14/ W/cm). The non-LTE physics is essential to correctly compute the level populations of the high Z atoms moving rapidly through a steep density gradient into the corona. This modeling also shows that x-rays are emitted in a thin overdense region, and on a time scale 50% longer than the laser pulse. Both of these effects are seen in the experiments.

One of the most difficult technology problems in an inertially confined fusion reactor is the survival of the structure from the repeated stresses caused by the microexplosion products. To mitigate the damage from the microexplosion products, a thick lithium fall can be circulated in front of the structure. This fall will absorb the short-ranged products and moderate and attenuate the neutrons. This paper discusses the response of the fall to the microexplosion products, and estimates the resulting loading and stresses in the first structural wall.

The Los Alamos Scientific Laboratory has an unirradiated enriched uranium reprocessing facility. Various types of solutions are generated in this facility, including distillates and raffinates containing ppm of uranium and concentrated solutions with up to 400 grams U/t. In addition to uranyl nitrate and HNO{sub 3}, the solutions may also contain zirconium, niobium, fluoride, and small amounts of many metals. A uranium solution assay system (USAS) has been installed to allow accurate and more timely process control, accountability, and criticality data to be obtained. The USAS assays are made by a variety of techniques that depend upon state-of-the-art high-resolution Ge(Li) gamma-ray spectroscopy integrated with an interactive, user-oriented computer software package. Tight control of the system`s performance is maintained by constantly monitoring the USAS status. Daily measurement control sequences are required, and the user is forced by the software to perform these sequences. Routine assays require 400 or 1000 seconds for a precision of 0.5% over the concentration range of 5--400 g/t. A comparison of the USAS precision and accuracy with that obtained by traditional destructive analytical chemistry techniques (colorimetric and volumetric) is presented.

None

None

None

The plateout distribution of gamma-emitting nuclides in the primary circuit of the Peach Bottom HTGR at end-of-life has been determined by in situ gamma scanning. The specific activity was mapped by scanning the accessible ducting at 12 locations with a Ge(Li) detector and by axially traversing 79 steam generator tubes with travelling CdTe detectors from the water side. Following destructive removal of trepan samples, a travelling intrinsic germanium detector was inserted sequentially into two vertical ducts and the plateout mapped along 6-m runs of ducting. Calibration measurements on mockups allowed reduction of the spectra to specific activity. The measured plateout profiles were in excellent agreement with those predicted with the PAD code. The dominant gamma emitters were Cs-137 and Cs-134; their relative distributions were similar. Little local structure to the plateout in the ducts was observed, only a gradual decrease in specific activity in the direction of coolant flow. In the steam generator, a significant entrance effect was observed in the superheater section; the activity was highest where the inlet jet impinged and lowest at the ends of the bundle despite the presence of a flow baffle. The effect damped out with penetration into the bundle, and the axial profile …

The nuclear processes considered in a recent LLL assessment of electronuclear breeding of fissile material are described. The nuclear cross sections and neutron yields measured in the MTA program (1949-1954), and the nuclear cascade calculations carried out then and in more recent times are briefly described. The probable advantage of deuterons over protons as particles to be accelerated is mentioned, and the need for a series of experiments to determine the choice of particle, optimum accelerator parameters and target system design is stressed.

A conceptual model of a neutral-beam injector was used to examine the effect of beam-line components on reactor performance. Criteria were established to optimize a reactor's reliability and minimize its cost.

The effects of D. C. electric fields on high lying Rydberg and valence states in atomic uranium have been studied. Results of measurements of Stark shifts, lifetime lengthening via l-mixing, critical fields for ionization, barrier tunneling, and the appearance of zero-field parity forbidden transitions are presented for atomic uranium along with the observation of field induced autoionization of valence states. 3 figs. (GHT)

Geothermal energy development research at the Lawrence Livermore Laboratory through 1976 has been aimed at solving the problems associated with the use of high-temperature, high-salinity brines found in the Salton Sea Geothermal Field for their practical conversion to electrical energy. Specifically, part of the program has been oriented toward solving the problems of scale and solids deposition and corrosion of system components that are exposed to the highly mineralized brines. Brine acidification was found to be a promising method for controlling scale and solids deposition. Titanium, zirconium, and chromium-molybdenum alloys were shown to be the best economical corrosion-resistant materials for use in various parts of a total-flow turbine system. Scale and solids control and materials tests for conversion systems based on brine flashing are currently being evaluated. Some initial results and test plans are discussed.

The particle beam parameters needed for inertial fusion can be achieved with conventional accelerator technology if heavy ion machines attain the level of performance of the most intense high energy proton machines. Many of the problems posed by this goal pertain to the low energy portions of the accelerator system. In particular, the implied particle current in the rf linac is 10/sup 3/--10/sup 4/ times the values achieved with existing heavy ion machines. Much of this discrepancy is simply attributable to the great differences between the design considerations relevant to accelerators for fusion and those which have determined the performance of the existing machines. The basic concept chosen at Argonne National Laboratory is cavities containing single drift tubes mounted on lambda/4 supports. Such structures pose the least problem for the beam transport system, and one cavity is placed between adjacent quadrupole magnets. The average voltage gain of the first cells of the low velocity section is moderate; and, although probably acceptable and improved by the end of the 10 MV section, the low initial gain adds to the motivation provided by the transport problem to increase the preinjector voltage substantially above 750 kV.

None

None

None

None

None