Some solutions to problems of compressing and containing tritium gas to 200 MPa at 700 K are discussed The principal emphasis is on commercial compressors and high-pressure equipment that can be modified easily by the researcher for safe use with tritium. Experience with metal belows and diaphragm compressors has been favorable. Selection of materials, fittings and gauges for high- pressure tritium work also is reviewed briefly.

The Arab oil embargo of 1973 focused national attention on energy problems. A national focus on development of energy sources alternative to consumption of hydrocarbons led to the initiation of research studies of reservoir engineering of geothermal systems, funded by the National Science Foundation. At that time it appeared that only two significant reservoir engineering studies of geothermal reservoirs had been completed. Many meetings concerning development of geothermal resources were held from 1973 through the date of the first Stanford Geothermal Reservoir Engineering workshop December 15-17, 1975. These meetings were similar in that many reports dealt with the objectives of planned research projects rather than with results. The first reservoir engineering workshop held under the Stanford Geothermal Program was singular in that for the first time most participants were reporting on progress inactive research programs rather than on work planned. This was true for both laboratory experimental studies and for field experiments in producing geothermal systems. The Proceedings of the December 1975 workshop (SGP-TR-12) is a remarkable document in that results of both field operations and laboratory studies were freely presented and exchanged by all participants. With this in mind the second reservoir engineering workshop was planned for December 1976. …

This volume includes the talks given on January 20, 1975, at a symposium in Berkeley on the occasion of the celebration of the 25th anniversary of the discovery of berkelium and californium. Talks were given at this symposium by the four people involved in the discovery of these elements and by a number of people who have made significant contributions in the intervening years to the investigation of their nuclear and chemical properties. The papers are being published here, without editing, in the form in which they were submitted by the authors in the months following the anniversary symposium, and they reflect rather faithfully the remarks made on that occasion.

Primary recoil distributions and specific damage energies have been computed for high energy deuteron-breakup neutrons in Cu, Nb, and Au. The calculations are based on theoretical neutron cross sections, and consider in particular a d-Be spectrum broadly peaked at 15 MeV with some neutrons above 30 MeV. The theoretical results are similar to corresponding calculations for monoenergetic 15-MeV neutrons and are in good agreement with range measurements of (n,2n) recoils generated by high energy d-Be neutrons in Nb and Au. The calculations are also consistent with recent d-Be neutron sputtering experiments in Nb and Au and demonstrate the usefulness of deuteron-breakup neutron sources for simulating fusion neutron effects. (auth)

Studies are presented of personnel exposures to $sup 252$Cf neutrons and gamma radiation during dosimetry experiments in mouse phantoms, fission foil detectors, and small tissue equivalent ionization chambers. Sensitivity of film badge emulsions to observed levels of $sup 252$Cf neutrons is discussed. Long- term personnel exposure histories are presented. Comparisons are made between neutron dose calculated from observed neutron-gamma ratios and the dose observed in neutron emulsions. Shielding used during experiments is described. (auth)

Aspects of low-dose, low-temperature irradiation experiments, and elevated-temperature experiments are reviewed. Information and data are included on methods of determining lattice atom displacement thresholds, lattice damage rates measured by changes in resistivity, ion damage, and neutron damage. (JRD)

Electron irradiation (2 MeV, up to 6 x 10$sup 18$ e/cm$sup 2$) decreased the yield stress of iron single crystals in the temperature range from 4.2 to 80$sup 0$K. The softening effect was highly dependent on the tensile axis orientation. The temperature and strain rate dependency of the yield stress was increased by the irradiation. The annealing of the softening took place between 90 and 150$sup 0$K. The observation is consistent with an intrinsic solid solution softening mechanism based on the enhancement of screw dislocation motion due to dispersed interstitials. (auth)

A brief review of the TFTR is given in terms of the physical size of the experiment in relation to existing and future tokamaks. Some break-even criteria are mentioned. (MOW)

In August, 1968, President Johnson announced that the people of Bikini Atoll would be able to return to their homeland. Thereafter, similar approval was given for the return of the peoples of Enewetak. These two regions, which comprised the Pacific Nuclear Testing Areas from 1946 to 1958, will probably be repopulated by the original inhabitants and their families within the next year. As part of its continuing responsibility to insure the public health and safety in connection with the nuclear programs under its sponsorship, ERDA (formerly AEC) has contracted Brookhaven National Laboratory to establish radiological safety and environmental monitoring programs for the returning Bikini and Enewetak peoples. These programs are described in the following paper. They are designed to define the external radiation environment, assess radiation doses from internal emitters in the human food chain, make long range predictions of total doses and dose commitments to individuals and to each population group, and to suggest actions which will minimize doses via the more significant pathways. (auth)

Physician acceptance of computer-enhanced radionuclide scan results, presented in the form of small Polaroid pictures, has been very limited for a number of subjective reasons. A new recorder was designed and constructed that presents the results of computer augmented scans through a medium that is quite familiar to doctors, the standard 14 in. x 17 in. x-ray film. (auth)

The skin thickness of blisters formed on polycrystalline niobium by $sup 4$He$sup +$ irradiation at room temperature for energies from 15 to 80 keV have been measured. Similar measurements were conducted for 10 keV $sup 4$He$sup +$ irradiation at 500$sup 0$C to increase blister exfoliation, and thereby allow examination of a larger number of blister skins. For energies smaller than 100 keV the skin thicknesses are compared with the projected range and the damage- energy distributions constructed from moments interpolated from Winterbon's tabulated values. For energies of 10 and 15 keV the projected ranges and damage- energy distributions have also been computed with a Monte Carlo program. For energies larger than 100 keV the projected ranges of $sup 4$He$sup +$ in Nb were calculated using either Brice's formalism or the one given by Schiott. The thicknesses for 60 and 80 keV, and those reported earlier for 100 to 1500 keV correlate well with calculated projected ranges. For energies lower than 60 keV the measured thicknesses are larger than the calculated ranges.

The sensitivity of neutron energy production to the impurity trapping of injected neutral beams is considered. This process is affected by inherent low-Z contamination of the tritium pre-heat plasma, by the species composition of the neutral beam, and by the entrance angle of the beam. The sensitivities of the process to these variables, and to the variation of wall material are compared. One finds that successful use of a low-Z, low-sputtering material can appreciably lengthen the useful pulse length. (auth)

The results clearly indicate that damage function analysis might be usefully applied to define both the neutron and primary recoil energy dependence of sputtering yields. Even with relatively large data errors, it appears that it is possible to both detect the existence and indicate the form of the deviation of sputtering yield from linear damage energy dependence (if such deviation exists). This information would be very useful in developing improved models of the sputtering phenomena.

Studies have been conducted to find materials with microstructures which minimize the formation of blisters. A promising class of materials appears to be sintered metal powder with small average grain sizes and low atomic number Z. Studies of the surface erosion of sintered aluminum powder (SAP 895) and of aluminum held at 400$sup 0$C due to blistering by 100 keV helium ions have been conducted and the results are compared to those obtained earlier for room temperature irradiation. A significant reduction of the erosion rate in SAP 895 in comparison to annealed aluminum and SAP 930 is observed. In addition results on the blistering of sintered beryllium powder (type I) irradiated at room temperature and 600$sup 0$C by 100 keV helium ions are given. These results will be compared with those reported recently for vacuum cast beryllium foil and a foil of sintered beryllium powder (type II) which was fabricated differently, than type I. For room temperature irradiation only a few blisters could be observed in sintered beryllium powder type I and type II and they are smaller in size and in number than in vacuum cast beryllium. For irradiation at 600$sup 0$C large scale exfoliation of blisters was observed …

As part of the structural response research program being conducted for ERDA, the response behavior of high-rise buildings in Las Vegas, Nevada, due to ground motion caused by underground nuclear explosions (UNEs) at the Nevada Test Site (NTS) has been measured for the past 12 years. Results obtained include variation in dynamic response properties as a function of amplitude of motion, influence of nonstructural partitions in the building response, and comparison of calculated and measured response. These data for three reinforced concrete high- rise buildings, all designed as moment-resisting space frames are presented. (auth)

Measurements of the elemental composition of the vacuum vessel wall surface and impurity influx into ATC during high power beam-heated discharges are combined with previous measurements of power balance and scaling laws to give a self consistent model of plasma-wall interaction in ATC. It is shown that plasma charge exchange induced desorption is the main cause of impurity influx during neutral beam injection. Impurities change the net power balance in these beam- heated discharges by approximately 15 percent. (auth)

Visible, ultraviolet, and infrared optical emission results from low- energy (20 eV-10 keV) particle-surface collisions. Several distinct kinds of collision induced optical radiation are discussed which provide fundamental information on particle-solid collision processes. Line radiation arises from excited states of sputtered surface constituents and backscattered beam particles. This radiation uniquely identifies the quantum state of sputtered or reflected particles, provides a method for identifying neutral atoms sputtered from the surface, and serves as the basis for a sensitive surface analysis technique. Broadband radiation from the bulk of the solid is attributed to the transfer of projectile energy to the electrons in the solid. Continuum emission observed well in front of transition metal targets is believed to arise from excited atom clusters (diatomic, triatomic, etc.) ejected from the solid in the sputtering process. Application of sputtered atom optical radiation for surface and depth profile analysis is demonstrated for the case of submonolayer quantities of chromium on silicon and aluminum implanted in SiO$sub 2$.

A method of separating the trivalent actinides, mainly Am and Cm, from trivalent lanthanides is presented. This method embodies the sequential use of two different solvent extractants; the first extractant would remove the heavy lanthanides from the lighter lanthanides and Am--Cm, while the second would extract Am--Cm in preference to the lighter lanthanides. In this scheme, no additional complexing agents are required. Thus, waste disposal and corrosion problems are minimized. Overall separation factors for Am--Cm from lanthanide fission products in reactor wastes may be as high as several thousand. (auth)

Processing of nuclear medicine images is generally performed by essentially linear methods with the non-negativity condition being applied as the only non-linear process. The various methods used: matrix methods in signal space and Fourier or Hadamard transforms in frequency or sequency space are essentially equivalent. Further improvement in images can be obtained by the use of inherently non-linear methods. The recent development of an approximation to a least-difference method (as opposed to a least-square method) has led to an appreciation of the effects of data bounding and to the development of a more powerful process. Data bounding (modification of statistically improbable data values) is an inherently non-linear method with considerable promise. Strong bounding depending on two-dimensional least-squares fitting yields a reduction of mottling (buttermilk effect) not attainable with linear processes. A pre- bounding process removing very bad points is used to protect the strong bounding process from incorrectly modifying data points due to the weight of an extreme but yet unbounded point as the fitting area approaches it. (auth)

A review of laser-compression experiments is given. Diagrams illustrating various compression data are described. (MOW)

The recent studies of particle emission from cold-rolled and annealed niobium under 14.1-MeV neutron impact were extended to a heavily etched, polycrystalline niobium surface and to cold worked vanadium surfaces with different degrees of microstructure. The type and amount of material released and deposited on collector surfaces facing the irradiated targets were determined by three analytical techniques. Two types of deposits were found for certain types of surfaces--one in the form of chunks; the other as a fractional atom layer covering the surface. The chunks vary significantly in size. The small number of chunks observed suggests that the ejection of chunks is a relatively rare event in comparison to the total number of primary knock-on events produced by 14-MeV neutrons in near surface regions. Estimates of the total sputtering yield based on the chunk deposits and on the fractional atom layer deposit will be given. (auth)

The stress introduced into a material in a monoenergetic helium-ion implantation is calculated for an ion beam with a gaussian intensity distribution. An effective beam spot of the order of several millimeters was chosen as typical of blistering experiments. The sample is assumed to be semi-infinite and isotropic. The ion distribution is cylindrically symmetric with a gaussian depth profile. The parameters defining the distribution are consistent with incident ion energies of approximately 40 and approximately 400 keV in both nickel and niobium. The volume expansion caused by the implanted ions is assumed to be proportional to the local helium concentration; the validity of this assumption is discussed. The maximum shear stress is calculated as a function of depth, and the volume expansion per helium atom required to produce plastic deformation at the experimentally observed critical doses in niobium is found to be of the order of one atomic volume.

The surface damage to insulating barium alumino-silicate glass coatings due to irradiation by 100 and 250 keV deuterons and helium ions at room temperature and at 300$sup 0$C has been studied. Blisters are observed after irradiation at room temperature with both deuterons and helium ions with energies of 100 and 250 keV. For deuteron irradiation a large fraction of the blisters have diameters which are approximately 3 to 5 times larger than the diameter observed with helium ions for identical irradiation conditions, but the density of blisters is nearly an order of magnitude lower. For irradiation at 300$sup 0$C, no blisters are observed with either type of particle. The sharp rise in permeation rate with temperature is thought to be responsible for this behavior. The blister skin thicknesses have been measured and correlated with calculated projected-range values.

Reflection of 50 eV to 10 keV H atoms from polycrystalline Cu, Nb and Au targets has been calculated using the binary collision cascade program MARLOWE. The fractions of particles and energy reflected (backscattered) increase with increasing atomic number of the target and decrease with increasing incident energy. The results indicate that the effects of polycrystallinity are modest, reducing the amorphous reflection coefficients by about 25 percent. The calculations agree quite well with the experimental data for Cu and Au, but are about a factor of two larger than is observed for Nb.