The 150 keV neutral beam test facility provides for the testing and development of neutral beam injectors and beam systems of the class that will be needed for the Tokamak Fusion Test Reactor (TFTR) and The Next Step (TNS). The test facility can simulate a complete beam line injection system and can provide a wide range of experimental operating conditions. Herein is offered a general description of the facility's capabilities and a discussion of present system performance.

Four neutral beam lines have been designed, constructed, and tested by the Oak Ridge National Laboratory (ORNL) in cooperation with the Princeton Plasma Physics Laboratory (PPPL) for application on the Princeton Large Torus (PLT) at PPPL. Two neutral beam lines are counterinjectors and two are coinjectors for a total neutral beam power of greater than 3 MW at 40 keV and up to 300 msec. Each beam line utilizes a 40-kV times 60-A modified duoPIGatron ion source with a close-coupled, 1.0-m long gas cell. Species ratios produced by the ion source are 84:13:3:E: E/2:E/3 for H/sup 0/ components delivered to the torus. The arc efficiency is less than 1 kW of arc power per ampere of beam current. Gas efficiency is approximately 50 percent with a total gas throughput of approximately 20 T-l/sec including supplemental gas to the gas cell. Two LHe cryocondensation pumps are used, one in the ion source tank with a speed of approximately 400,000 l/sec and the other in the drift tube with a speed of approximately 20,000 l/sec. The first beam line has been operated on PLT and has delivered 500 kW to the tokamak calorimeter for 150 msec. Initial heating results at 400 kW …

Systems ecology techniques have been useful in simulating the fate and dynamics of radionuclides in forest ecosystems. The applications of systems models in this context are twofold: projection of the time-dependent distribution of radioisotopes among various ecosystems components, and manipulation of the modeled system to determine the sensitivity of components to variation in transfer coefficients and, thereby, identify critical fluxes affecting system behavior. The present paper describes a systems model that projects the possible fate of plutonium in a deciduous forest ecosystem. The isotopes of interest are /sup 239/Pu and /sup 240/Pu which have physical half lives of 2.44 x 10/sup 4/ and 6540 years, respectively. These isotopes are indistinguishable by alpha spectrometry hence /sup 239/Pu is used to refer to both.

Measurements have been made of the total back-scattered D/sup -/ yields from Cs, Rb, K, Na and Li surfaces bombarded with D/sub 2//sup +/ and D/sub 3//sup +/ in the energy range 0.05 to 3.5 keV/nucleon. All measurements were made at a background pressure less than 10/sup -9/ Torr and the alkali-metal surfaces were evaporated onto a substrate in situ to assure uncontaminated surfaces. For each target, the D/sup -/ yield is at a maximum (as high as 12% per incident deuteron for Cs) between 150 and 300 eV/nucleon, and at any measured energy, the D/sup -/ yield decreases from Cs to Li in the order given above.

During the last ten years, photoelectron angular distributions have been used extensively to study the dynamics of the photoionization process in atoms and molecules. Some major advances in this body of work are reviewed with special emphasis on results emerging since the last Conference on VUV Radiation Physics three years ago. By far the greatest progress has occurred for atoms, where interest is focussed on improving zero-order (Hartree-Slater, Cooper-Zare) understanding of the asymmetry parameter ..beta..(epsilon), by considering electron correlations, relativistic effects, and anisotropic final-state interactions. The study of the rare gases has benefitted from extensive coordination between experiment and theory, whereas work on nonspherical atoms has been mainly theoretical, with the only measurements being performed very recently on atomic oxygen. Angular distribution studies on molecules are in a much earlier stage of development. Progress has been impeded by the lack of practical, realistic theoretical methods and wavelength-dependent measurements, both of which are becoming available only now. This recent work, together with selected topics from earlier resonance-line work on molecules will be reviewed. In addition, a new class of angular-dependent studies of molecules will be discussed--the angular distribution of nonthermal ions formed by dissociative photoionization--which provides information complementary to the related …

There are three perspectives with which to view the interaction of Corbicula and power plants: as a fouling agent; as an important part of the natural ecosystem; and as a potential species for use in waste heat aquaculture. The first two of these interactions are essentially negative in character, since they involve avoidance of impacts either of Corbicula on power plant operation or of power plant operation on Corbicula. Condenser fouling by these claims has been controlled by mechanical means or by continuous chlorination. Our data support the potential for using heated water to control fouling and a model for determining required thermal dosing is presented. Preliminary data also indicate potential for control by combining simultaneous short-term exposure to hot water and chlorine. The third of the interactions is essentially positive in character. The use of thermal effluents in Corbicula aquaculture systems is proposed.

Twenty papers were included covering the Edna Delcambre Test Well, legal studies, environmental studies, economic studies, and resource utilization. Separate abstracts were prepared for each paper. (MHR)

Neutralization of H/sup -/ beams by a hydrogen plasma is discussed. Optimum target thickness and maximum neutralization efficiency as a function of the fraction of the hydrogen target gas ionized is calculated for different H/sup -/ beam energies. Also, the variation of neutralization efficiency with respect to target thickness for different H/sup -/ beam energies is computed. The dispersion of the neutralized beam by a magnetic field for different energies and different values of B . z is found. Finally, a type of plasma jet is proposed, which may be suitable for a compact H/sup -/ neutralizer.

Walker Branch Watershed is located on the Oak Ridge Reservation in the Ridge and Valley section of Tennessee. The watershed (97 ha consisting of 2 subwatersheds) is underlain by Knox Dolomite; soils formed over the dolomitic substrate are deep, well-drained Typic Paleudults. The watershed is forested. The overstory is predominantly oak-hickory with lesser amounts of pine and mesic hardwoods. The Walker Branch Watershed Project was initiated in 1967 to: relate the productivity and water quality of the stream to the productivity and nutrient balance of the adjacent terrestrial ecosystem; relate the net loss of nutrient elements to the rate of nutrient cycling; define the relationship between the hydrologic cycle and nutrient flux; provide benchmark information on natural terrestrial-aquatic ecosystems for comparison with man-modified situations; and to enable the measurement of environmental degradation caused by man's cultural practices. Research has been completed or is on-going in several distinct, but related, areas: ecosystem analysis of essential element dynamics (N, P, K, Ca, Mg and C), atmospheric and hydrologic input-output processes, trace element biogeochemistry (e.g., Cd, Pb, Zn) and sulfur. Research objectives have been approached by analysis of the role of important biological and physical processes, and the development of mathematical models.

Experimental measurements of the production of H/sup -/ from surfaces bombarded with hydrogen are reviewed. Some measurements of H/sup +/ and H/sup 0/ production from surfaces are also discussed with particular emphasis on work which might be relevant to ion source applications.

An apparatus was constructed for measurement of the density and volumetric thermal expansion of high temperature molten materials using the gamma attenuation technique. It was found that significant improvements in overall experimental precision could be realized by employing an automatic gain control in the linear section of the gamma counting system. This device reduced errors due to system gain shifts and thereby increased the precision of the gamma counting. Corrections were also made for the dead time of the electronics system. A preliminary experimental investigation of the precision of the method was made by measuring small dimensional steps of a tool steel block at a single temperature. A fractional length increment ..delta..l/l of 1% was determined to 1%, equivalent to a length change precision of 10/sup -4/ cm/cm. In addition, the precision of the experimental technique was analytically examined for both absolute and relative density determinations. Three analytical expressions used to reduce data for liquid density determinations were evaluated for their precision. Each allows use of a different set of input data parameters, which can be chosen based on experimental considerations. Using experimentally reasonable values for the precision of the parameters yields a similar resultant density precision from the three …

The formation of negative ions by hydrogen collisions on cesium-coated surfaces is discussed in the limiting cases where the resident cesium is either in the purely ionic state or in the purely atomic state. The survival fraction for negative ions moving away from a metal surface is calculated using a method employing complex eigenvalues. The fraction of surviving ions is found to be larger than calculated by previous workers. The secondary emission coefficient for negative ion production by incident atoms with energies of ten to one hundred electron volts is estimated to be in the range thirty to fifty percent. The secondary emission coefficient is found to be a sensitive function of the thickness of the alkali adsorbate coating for ion energies in the range below a few hundred electron volts.

Changes in the topology of the Fermi surfaces of metals occur with variation of temperature or stoichiometry in a number of metallic systems of current interest. Pressure generated by a variety of techniques has proven to be the most useful experimental variable in the study of these transitions, but in most cases only solid He techniques yield sufficiently hydrostatic conditions to permit direct measurements of the Fermi surface as a function of pressure.

Separate abstracts were prepared for 30 papers presented.

The topics considered in the seven sessions were nuclear methods in atmospheric research; nuclear and atomic methodology; nuclear methods in tracer applications; energy exploration, production, and utilization; nuclear methods in environmental monitoring; nuclear methods in water research; and nuclear methods in biological research. Individual abstracts were prepared for each paper. (JSR)

Based on the Oak Ridge National Laboratory (ORNL) source development program, ways to create a uniform and dense plasma are briefly reviewed. The positive ions so created will be accelerated towards a surface convertor for producing negative ions. The convertor will be used for reducing the electrons in the extraction region. The significant results and features of this study are presented.

This article discusses K-shell x-rays of selected elements from Nb through Gd for incident protons and alpha particles from 0.6 to 2.4 MeV.

Some examples of atomic-related research to the fusion energy program are described. An overall spectrum of radiation from ORMAK in the 40 to 70 A range is shown. Power losses through impurities are discussed. (MOW)

Experimental and theoretical research on production of negative ion beams is described. Results from a double charge-exchange experiment include 10 ms pulses of 100 ma of D/sup -/ accelerated to 60 kV. Equilibrium fractions of D/sup -/ in several metal vapors are presented. Mechanisms and measurements of D/sup -/ on surfaces are described, and a scheme is shown for producing high current, high energy beams originating on surfaces.

Abstracts are included for approximately 100 of the papers presented at the meeting. The following sessions were held at the conference: (1) electron ionization and excitation rates, (2) radiation from low density plasmas, (3) electron-ion cross sections and rates, (4) oscillator strengths and atomic structure, (5) spectroscopy and atomic structure, (6) astrophysical plasmas, (7) particle transport, (8) ion-atom cross sections and rates, (9) wall effects in laboratory plasmas, (10) spectroscopy and photoionization, and (11) radiation from high density plasmas. (MOW)

The concept of cost-benefit analysis in relation to the assessment of various factors causing stress on natural ecosystems is discussed. It is pointed out that if stress is considered in the context of a deviation from some homeostatic condition, we do face a number of technical and socially related questions. The technical questions are those concerning the need to define in rigorous scientific terms the meaning of ecosystem homeostasis. What is the significance, both temporally and spatially, of a deviation from such homeostasis, and of the elucidation in quantitative terms of the acceptability and nonacceptability of such a deviation. The latter, of course, puts us into our role as scientist-citizens. There we enter the realm of value judgment where we provide only one of many inputs which need to be considered by an institutional decision-maker.

The newly formed SAFE Subcommittee of the Cross Section Evaluation Working Group is charged with the responsibility for providing, reviewing, and testing several ENDF/B special purpose evaluated files. This responsibility currently encompasses dosimetry, activation, hydrogen and helium production, and radioactive decay data required by a variety of users. New formats have been approved by CSEWG for the inclusion of the activation and hydrogen and helium production cross-section libraries. The decay data will be in the same format as that already employed by the Fission Product and Actinide Subcommittee of CSEWG. While an extensive dosimetry file was available on the ENDF/B-IV library for fast reactor applications, other data are needed to extend the range of applications, especially to higher incident neutron energies. This Subcommittee has long-range plans to provide evaluated neutron interaction data that can be recommended for use in many specialized applications. 1 figure, 3 tables

Walker Branch Watershed, a 97.5 ha deciduous forest catchment on dolomitic terrain, received annual precipitation averaging 151.1 cm over a six-year period from 1970-1976. Approximately 56 percent of this precipitation left the watershed as streamflow. Soil evaporation and canopy interception with subsequent evaporation loss were well represented by relationships derived for eastern hardwoods and amounted to about 12 percent of precipitation. Transpiration accounted for the remainder (31 percent) of the water loss from the watershed. Seasonal precipitation-streamflow balances show that precipitation is relatively uniformly distributed throughout the year, while streamflow varies seasonally with high flows from December through May and low flows from June through November. Baseflow discharge patterns from the two subcatchments are different, the smaller basin yielding relatively more than the larger one. This difference is thought to be due to groundwater exchange between the two through channels in the dolomitic bedrock. The hydrologic data base is used extensively in nutrient and trace element cycling studies and in development of mechanistic hydrologic models.

Short summaries of conference papers are presented. Some of the conference topics included transport properties, defect levels, superionic conductors, radiation effects, John-Teller effect, electron-lattice interactions, and relaxed excited states. (SDF)