Since September, 1952, Lawrence Livermore Laboratory has conducted pioneering research in applied science. A vital part of this activity has been the development of a variety of high vacuum and ultrahigh vacuum systems. Leaks occur in everything, including vacuum systems. The mass spectrometer leak detection equipment is described.

The rate of pitch-angle scattering in a beam-driven Tokomak is proportional to Z/sub eff/ when neutral deuterium is injected parallel or antiparallel to the toroidal field B/sub T/. The energy spectrum of neutrons produced by D--D or D--T reactions is sensitive to the angular distribution of reacting energetic deuterons so that a measurement of the spectrum may be used to infer Z/sub eff/. Energy spectra of neutrons emitted parallel to B/sub T/ during simultaneous co- and counter-injection were calculated for the case of 120-keV beams by using a PPPL code. The results were then convoluted with spectrometer lineshapes determined experimentally for a system used to measure neutron spectra during a 1.0-s source pulse. Results indicate that Z/sub eff/ in the range of 1 to 4 may be determined with uncertainties of +- 0.25 for D--D plasma and +- 0.5 for D--T plasma, provided the ion temperature T/sub i/ is well known. However, the spectrometer energy resolution is not adequate to determine T/sub i/ directly from a neutron--spectrum measurement. In the absence of accurate T/sub i/ data, the uncertainty in Z/sub eff/ is approximately +- 1. In either case, impurity identification is not established by this type of measurement.

The CORA code is a steady state/transient, core thermal hydraulics code for the FFTF Reactor. A brief overview of the code development and use is presented.

The MARK I boiling water reactor (BWR) containment system is comprised of a light-bulb-shaped reactor compartment connected through vent pipes to a torus-shaped and partially water-filled pressure suppression chamber, or the wetwell. During either a normally occurring safety relief valve (SRV) discharge or a hypothetical loss-of-coolant accident (LOCA), air or steam is forced into the wetwell water pool for condensation and results in hydrodynamically induced loads on the torus shell. An analytical program is described which employs the finite element method to investigate the influence of torus wall flexibility on hydrodynamically induced pressure and the resultant force on the torus shell surface. The shell flexibility is characterized by the diameter-to-thickness ratio which is varied from the perfectly rigid case to the nominal plant condition. The general conclusion reached is that torus wall flexibility decreases both the maximum pressure seen by the shell wall and the total vertical load resulted from the hydrodynamically induced pressure.

One organization's approach to designing complex, interrelated databases is described. The problems encountered and the techniques developed are discussed. A set of software tools to aid the designer and to produce an initial database design directly is presented. 5 figures.

Materials accounting for special nuclear material in future fuel cycle facilities will draw heavily on sophisticated data-analysis techniques. Decision analysis, which combines elements of estimation theory, decision theory, and systems analysis, can be used to reduce errors caused by subjective data evaluation and to condense large collections of data to a smaller set of more descriptive statistics. The methods and requirements of decision analysis are discussed and illustrated by a conceptual design example of an advanced materials accounting system for a plutonium nitrate-to-oxide conversion facility.

A subcommittee of the American Crystallographic Association (ACA) was formed to recommend some guidelines that would improve the overall quality of published powder diffraction data. An analysis of the Powder Diffraction File shows that many of the well-known techniques for obtaining good quality data are often not being applied, and hence there is a need for the establishment of publication standards. A major recommendation from this subcommittee is the use of a standard data-form at the author/referee level of publication. The proposed data-form is divided into five sections: sample characterizaton, technique, unit cell data, references, and the powder data. The information asked for in these five sections represents what, in most cases, the referee and editor can reasonably expect of experimenters seeking to publish their powder data. An example of a filled-out form is shown, and instructions for completing the form are given. Another recommendation is that the ACA request that the International Union of Crystallography consider implementing these recommendations in all IUCr journals.

Experiments have been performed with a 125-kJ plasma focus to investigate mechanisms for rapid coupling of inductively-stored energy into plasmas. The coupling can take place through the formation of an electron or ion beam that deposits its energy in a target or directly by the penetration of the magnetic field into a resistive plasma. Some preliminary results from experiments of both types are described. The experiments use a replaceable conical anode tip that is intended to guide the focus to within a few millimeters of the axis, where it can suddenly deliver energy either to a small target or to particles that are accelerated. X-ray and fast-ion diagnostics have been used to study the effects.

A unique model of fusion product (fp) slowing down and thermalization in field-reversed mirror (FRM) plasmas has been developed. It couples the Hill's spherical vortex representation of a field-reversed equilibrium with a monte carlo treatment of coulomb scattering, and thus provides a complete picture of fps from birth through their thermal diffusion. The incorporation of drag and scattering effects allows the code to address both the energy deposition and the ash buildup question. Results of several test cases are presented along with selected results from FRM studies.

New laboratory data are reported on the effect of confining (lithostatic) pressure, pore-water pressure, and principal stress difference on permeability of Westerly granite and White Lake gneissic granite. Permeabilities as low as 10/sup -19/ cm/sup 2/ (10/sup -11/ D) have been measured successfully, using a transient technique. Principal strains, electrical conductivity, and compressional velocity are determined simultaneously. Applied loads on the 15-cm diameter by 28-cm long test sample are controlled automatically and all data are taken by a microcomputer. Results on the gneissic granite indicate permeabilities of 10/sup -18/ to 10/sup -19/ cm/sup 2/ that appear to be unaffected either by effective pressure or by stress. The granite yields permeabilities of 4x10/sup -16/ cm/sup 2/ that decrease by a factor of two with pressure and vary by a factor of two with stress. When compared to the initial value, compressional velocities increase by 4% and conductivity decreases by 50% as pressure is increased to 50 MPa in the gneissic granite. In granite, these become 3% and 58%, respectively. At pressure, loading of the granite of 0.5 of failure stress increases conductivity by about 20%.

The probabilistic approach to nuclear reactor safety is playing an increasingly significant role. For the liquid-metal fast breeder reactor (LMFBR) in particular, the ultimate application of this approach could be to determine the probability of achieving the goal of a specific line-of-assurance (LOA). Meanwhile a more pressing problem is one of quantifying the uncertainty in a calculated consequence for hypothetical core disruptive accident (HCDA) using large codes. Such uncertainty arises from imperfect modeling of phenomenology and/or from inaccuracy in input data. A method is presented to determine the confidence level in consequences calculated by a large computer code due to the known uncertainties in input invariables. A particular application was made to the initial time of pin failure in a transient overpower HCDA calculated by the code MELT-IIIA in order to demonstrate the method. A probability distribution function (pdf) for the time of failure was first constructed, then the confidence level for predicting this failure parameter within a desired range was determined.

A comparison is made between three different dynamic analysis methods commonly used in the analysis of nuclear facilities. The methods are applied to a typical non-reactor type nuclear facility; namely, an early configuration of the High Performance Fuel Laboratory which was to have been designed and constructed to house an automated fuel process line on the Hanford Reservation near Richland, Washington. The fuel to be handled was mixed plutonium and uranium in powder and pellet form which, therefore, required design for severe earthquake and tornado conditions. The structure is a two-story reinforced concrete shear wall building with a high bay on one end. The comparison is made for earthquake motion in the lateral horizontal direction only. The first method employs a three degree of freedom spring mass system with the masses lumped at the three floor and roof slab levels. After shears are obtained they are distributed to the shear walls in proportion to their stiffnesses. Floor and roof slabs are assumed rigid but eccentricities are accounted for in the shear distribution. The second method utilizes a pseudo three-dimensional stick model. The shear walls and horizontal floor and roof diaphram are modeled as three dimensional beam elements using the SAP …

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Recent experiments with high Z disks on the Argus facility have exteanded our knowledge of the temperature (inferred from the slope of the hard x-ray spectrum) of laser generated suprathermal electrons, from the previous regime of 1 less than or equal to Z less than or equal to 30 to the Z approx. = 80 regime. The systematic rise of temperature with Z is theoretically analyzed. We believe that material albedoes (electron reflectivity) which increase with Z can account for this behavior, since electrons can make multiple passes through the region of resonant electric fields and are thus reheated. We treat this effect quantitatively and obtain reasonable agreement with experiment. The effects of magnetic fields and filamentation are also examined.

In our laser fusion microsphere production, large, thin gel-microspheres are formed before the chemicals are fused into glass. In this transient stage,, the gel-microspheres are found to be highly permeable to argon and many other inert gases. When the gel transforms to glass, the argon gas, for example, is trapped within to form argon filled, fusion target quality, glass microspheres. On the average, the partial pressure of the argon fills attained in this process is around 2 x 10/sup 4/ Pa at room temperature.

A system for measuring argon contents in individual laser fusion targets using a getter pumped closed volume quadrupole mass spectrometer has been developed. Accuracy of 10% can be obtained, limited by the calibration standard and electron multiplier drift. Measurements are simple, unambiguous and can be performed at up to one per hour with a sensitivity equivalent to 1 x 10/sup 3/ Pa (.01 atm) argon in a 140 ..mu..m internal diameter sphere.

The Fusion Materials Irradiation Test Facility (FMIT) is a high-energy, high-flux neutron source for fusion materials development. The FMIT linear accelerator will produce a 35 MeV beam of deuterons that generates high-energy neutrons by a nuclear stripping reaction with flowing liquid lithium targets. The targets will be located in two identical irradiation test cells, either of which will provide an irradiation volume of 10 cm/sup 3/ at a neutron flux of 10/sup 15/ n/cm/sup 2/-s and 500 cm/sup 3/ at a flux of 10/sup 14/ n/cm/sup 2/-s. FMIT has been authorized by the US Congress and will be constructed and operated by the Hanford Engineering Development Laboratory (HEDL) at Richland, Washington, in collaboration with the Los Alamos Scientific Laboratory (LASL) which is providing the accelerator design. The project is currently entering the detailed design phase, targeting for start of construction in early 1980 and operaion in 1983-84. Research and development programs are underway at both HEDL and LASL to resolve uncertainties in the lithium target and accelerator designs.

A method is described whereby the absolute radiative quantum efficiency of paramagnetic ions in liquids or solids can be determined from photoacoustic measurements. 1 figure.

Livermore results are reviewed and compared with recent measurements of high energy ions in the plasma focus device at other laboratories. We will also discuss diagnostic techniques for measuring high energy ions including nuclear activation, particle track detectors, solid state (silicon PIN) detectors, and neutron time-of-flight measurements.

The theory for photoacoustic-induced stress in condensed media is developed both for near-field and far-field conditions.

Attenuation results from geometric spreading and from absorption. The former is almost independent of crustal geology or physiographic region. The latter depends strongly on crustal geology and the state of the earth's upper mantle. Except for very high-frequency waves, absorption does not affect ground motion at distances less than 25 to 50 km. Thus, in the near-field zone, the attenuation in the eastern United States will be similar to that in the western United States. Most of the differences in ground motion can be accounted for by differences in attenuation caused by differences in absorption. The other important factor is that for some Western earthquakes the fault breaks the earth's surface, resulting in larger ground motion. No Eastern earthquakes are known to have broken the earth's surface by faulting. The stress drop of Eastern earthquakes may be higher than for Western earthquakes of the same seismic moment, which would affect the high-frequency spectral content. This factor is believed to be of much less significance than differences in absorption in explaining the differences in ground motion between the East and the West. 6 figures.

We have successfully developed a new process for making strong, smooth, thick SiO/sub 2/ films on hemispherical Kovar mandrels of various sizes designed for multishell Laser Fusion Targets. The surface finish obtainable with a 13 ..mu..m thick SiO/sub 3/ coating on a 260 ..mu..m dia. mandrel is approximately 30 nm peak-to-peak, with a few defects of roughly 0.3 ..mu..m deep. The rf magnetron sputtered SiO/sub 2/ films were dense and crystalline.

A crossed molecular beam study was made of the reactions of U with inorganic oxidizers (O/sub 2/, NO, SO/sub 2/, N/sub 2/O, CO/sub 2/), water, alcohols, acetone, and halogenated methanes. Results show that U in the gas phase behaves very much like most other heavy metals, and may be called a heavy Ba or Sn atom. 8 figures. (DLC)

On the basis of time-integrated emittance measurements, several different types of field emitter diodes were characterized at 1 to 3 kA, 1 MeV. These measurements were part of the design effort for the injector system of a linear induction accelerator, to be used as a flash x-ray source at Lawrence Livermore Laboratory. The experimental parameters were the cathode type, the anode mesh texture, the diode spacing and voltage, and the level of collimation of the emerging beam. Experimental results are presented that show that over a wide range, the emittance was proportional to the level of collimation. For any one diode, with the spacing left fixed, the emittance was found to be essentially independent of the diode voltage and current. Differential focusing of different energy beam components affects most strongly the peripheral components of the beam, and strong collimation was found to minimize the effects of momentum spread on the emittance. The lowest emittances (30 to 40 mr-cm at 400 A) were obtained with a foil-type cathode in a ball-over-plane configuration, using an etched tungsten mesh anode, and collimating the beam to one quarter of the total current.