Initiation and growth of a crack in the Charpy V-notch test was investigated by performing both static and impact controlled deflection tests. Test specimens were deformed to various deflections, heat-tinted to mark crack extension and broken apart at low temperature to allow extension measurements. Measurement of the crack extension provided an estimate of crack initiation as defined by different criteria. Crack initiation starts well before maximum load, and is dependent on the definition of ''initiation''. Using a definition of first micro-initiation away from the ductile blunting, computer model predictions agreed favorably with the experimental results.

A /sup 1///sub 5/-scale test facility of a pressure-suppression system from a Mark I boiling water reactor was instrumented with seven types of transducers to obtain high-accuracy, dynamic loading data during a hypothetical loss-of-coolant accident. A total of 27 air tests have been completed with an average of 175 transducers recorded for each test. An end-to-end calibration of the total measurement system was run to establish accuracy of the data. The instrumentation verified the analysis of the dynamic loading of the pressure-suppression system.

Crack initiation and growth in the Charpy V-notch test are investigated for controlled deflections of the specimen applied both by slow bending and by impact. Charpy test specimens were deformed to various deflections, heat-tinted to mark the crack extensions, and broken apart at low temperature to allow measurement of the crack extensions. These measurements provide estimates of crack initiation as defined by various criteria. The loading point at which crack initiation occurs depends on the particular definition being used for ''initiation,'' but in all cases it is well before the maximum load is reached. When initiation is defined as the first observable micro-initiation away from the ductile blunting of the notch root, the experimental results are in good agreement with computer modeling predictions.

Nb/sub 3/Ge films fabricated by magnetron sputtering at substrate temperatures T/sub s/, from 600 to 850/sup 0/C and film thicknesses of 1 to 5 ..mu..m have been analyzed with respect to transition temperature T/sub c/, critical current density as a function of applied field J/sub c/(H), and grain size. J/sub c/ at 5Tesla shows a strong dependence on T/sub s/, decreasing by more than an order of magnitude as T/sub s/ increases from 700 to 815/sup 0/C. This decrease will be related to grain diameter D. Results will be presented which suggest a lower J/sub c/(H) in thicker films prepared at a fixed T/sub s/ is caused by increased grain diameters as the films grow in thickness. Evidence will be presented showing these results to be consistent with grain boundaries being the dominant pinning mechanism in these films.

Obtaining diffraction-limited images in the presence of atmospheric turbulence is a topic of current interest. Two types of approaches have evolved: real-time correction and speckle imaging. A speckle imaging reconstruction method was developed by use of an ''optimal'' filtering approach. This method is based on a nonlinear integral equation which is solved by principle value decomposition. The method was implemented on a CDC 7600 for study. The restoration algorithm is discussed and its performance is illustrated. 7 figures.

A solenoid coil, 105 cm inside the 167 cm outside diameter, has been constructed and tested to study the performance of the stabilized Nb--Ti conductor to be used in the Mirror Fusion Test Facility (MFTF) being built at Lawrence Livermore Laboratory. The insulation system of the test coil is identical to that envisioned for MFTF. Cold-weld joints were made in the conductor at the start and finish of each layer; heaters were fitted to some of these joints and also to the conductor at various locations in the winding. This paper gives details of the construction of the coil and the results of the tests carried out to determine its propagation and recovery characteristics.

The principal objectives of the SLPX (Superconducting Long-Pulse Experiment) are: (1) to demonstrate quasi-steady operation of 3 to 5 MA hydrogen and deuterium tokamak plasmas at high temperature and high thermal wall loading, and (2) to develop reliable operation of prototypical tokamak reactor magnetics systems featuring a toroidal assembly of high-field niobium-tin coils, and a system of pulsed niobium-titanium superconducting poloidal-field coils. This paper describes the status of the engineering design features of the SLPX, with emphasis on the magnetics systems. The toroidal-field coils have an aperture of 3.1 x 4.8 m and can operate with a maximum field at the conductor of 12 T. The superconducting poloidal field magnetics system consists of a pulsed NbTi central solenoid and a set of dc NbTi equilibrium-field coils. The entire machine is enclosed in an outer vacuum container equipped with re-entrant ports that provide ambient access to the room-temperature plasma vessel.

A two-phase turbine, using a low-quality steam-water mixture as a working fluid, was designed, built, and tested in the laboratory. Two-phase fluids are found naturally in most geothermal fields throughout the world and can also be used in the conversion of waste heat from industrial sources. The thermodynamic and fluid-dynamic properties of such fluid mixtures are reviewed, with specific reference to the selection and design of an appropriate expander. Various types of practically realizable expanders are considered, and the choice of a single-stage, axial-flow, impulse turbine is explained. Also the basic design parameters, including sizing and blade and nozzle geometry, are described.