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Interest in interactive 3-D graphics has exploded of late, fueled by (a) the allure of using scientific visualization to go where no-one has gone before'' and (b) by the development of new input devices which overcome some of the limitations imposed in the past by technology, yet which may be ill-suited to the kinds of interaction required by researchers active in scientific visualization. To resolve this tension, we propose a flat 5-D'' environment in which 2-D graphics are augmented by exploiting multiple human sensory modalities using cheap, conventional hardware readily available with personal computers and workstations. We discuss how interactions basic to 3-D scientific visualization, like searching a solution space and comparing two such spaces, are effectively carried out in our environment. Finally, we describe 3DMOVE, an experimental microworld we have implemented to test out some of our ideas. 40 refs., 4 figs.

High surface electric fields have been obtained in the first tests of a superconducting rf quadrupole device. The rf quadrupole fields were generated between niobium vanes 6.5 cm in length, with an edge radius of 2 mm, and with a beam aperture of 6 mm diameter. In tests at 4.2 K, the 64 MHz device operated cw at peak surface electric fields of 128 MV/m. Virtually no electron loading was observed at fields below 100 MV/m. It was possible to operate at surface fields of 210 MV/m in pulses of 1 msec duration using a 2.5 kW rf source. For the vane geometry tested, more than 10 square centimeters of surface support a field greater than 90% of the peak field. The present result indicates that electric fields greater than 100 MV/m can be obtained over an appreciable area, sufficient for some accelerator applications. It also shows that superconducting rf technology may provide an extended range of options for rf quadrupole design. 7 refs., 4 figs.

Differential geometry provides a natural family of coordinate systems, the Frenet frame, in which to specify the geometric properties of magnet winding. By a modification of the Euler-Bernoulli thin rod model, the strain energy is defined with respect to this frame. Then it is minimized by a direct method from the calculus of variations. The mathematics, its implementation in a computer program, and some analysis of an SSC dipole by the program will be described. 16 refs.

A series of experiments was conducted using SRL 165 synthetic waste glass to investigate the effects of surface preparation and leaching solution composition on the alteration of the glass. Samples of glass with as-cast surfaces produced smooth reaction layers and some evidence for precipitation of secondary phases from solution. Secondary phases were more abundant in samples reacted in deionized water than for those reacted in a silicate solution. Samples with saw-cut surfaces showed a large reduction in surface roughness after 7 days of reaction in either solution. Reaction in silicate solution for up to 91 days produced no further change in surface morphology, while reaction in DIW produced a spongy surface that formed the substrate for further surface layer development. The differences in the surface morphology of the samples may create microclimates that control the details of development of alteration layers on the glass; however, the concentrations of elements in leaching solutions show differences of 50% or less between samples prepared with different surface conditions for tests of a few months duration. 6 refs., 7 figs., 1 tab.

An examination of a coherency criteria for high velocity jets is discussed in this paper. An analysis of the classical Pugh, Eichelberger, Rostoker jetting theory is used to develop an equation that defines the maximum coherent jet velocity as a function of the liner material sound speed, the liner beta angle, and the magnitude direction of the liner collapse velocity vector. The liner material sound speed is assumed to be the liner material shock velocity at the time of liner material collapse. This shock velocity is a function of the collapse pressure in the stagnation region and thus varies with time and position along the liner. The analysis indicates that coherent jets at velocities greater than three times the liner shock velocity are possible with some combinations of the beta and collapse vector angles while incoherent jets at velocities equal to two times the liner shock velocity could occur with other combinations. The objectives of this paper are to examine the theory used to calculate jet velocity and to develop a criteria for calculating the maximum coherent jet tip velocity. 13 refs., 6 figs.

A preliminary measurement of the properties of W and Z production along with accompanying jets has been made in {anti p}p collisions at 1.8 TeV using the CDF detector at Fermilab. Distributions of jet multiplicity, and boson E{sub T}, with and without selection on jet multiplicity, were obtained. Agreement was found with perturbative QCD predictions.

In the analysis of magnetic flux creep experiments it is assumed that, at a given temperature, the pinning energy which must be overcome by thermal activation depends on the magnetic induction and its gradient by U(B,{nabla}B){congruent} U{sub p}(B)(1-{nabla}B/{nabla}B{sub max}){sup n} where U{sub p} is the pinning well depth and {nabla}B{sub max} corresponds to the critical current density with no thermal activation. Customarily, n is assumed to be unity and any unusual temperature dependence of U{sub p} is then ascribed to a distribution of well depths. However, realistic assumptions about the shape of the pinning potential yield 3/2 {approx lt} n {approx lt} 2, which yields an apparent distribution of well depths in the conventional analysis. Simple models will be used to illustrate the characteristics of these two quite different origins for the apparent temperature dependence of well depth obtained from magnetic flux creep rates. 13 refs., 8 figs.

We present the design of a 250 GHz, 400 MW Cyclotron Auto Resonance Maser (CARM) oscillator driven by a 1 KA, 2 MeV electron beam produced by the induction linac at the ARC facility of LLNL. The oscillator circuit is designed as a feedback amplifier operating in the TE{sub 11} mode at ten times cutoff terminated at each end with Bragg reflectors. Theory and cold test results are in good agreement for a manufactured Bragg reflector using 50 {mu}m corrugations to ensure mode purity. The CARM is to be operational by February 1990. 3 figs., 2 tabs.

Sintered bars of Y-Ba-Cu oxide were partially melted using a quartz halogen lamp zone heating apparatus. The resulting multiphase samples showed varying degrees of melt texturing.'' It was found that the addition of YBa{sub 2}CuO{sub 5} powders to the sintered YBa{sub 2}Cu{sub 3}O{sub 7} prior to the zone melting process enhanced the growth of large textured grains. The best value of the critical current density was {approximately}10{sup 3} A/cm{sup 2} at 1.0 T and 77 K for the starting composition of YBa{sub 2}Cu{sub 3}O{sub 7} {sm bullet} (0.2)Y{sub 2}BaCuO{sub 5}. 11 refs., 5 figs.

The remnant magnetic flux distribution in a single crystal and a sintered polycrystal was examined using the magnetic particle decoration technique. The single crystal, which was heavily twinned, showed only local order in the flux lattice. This was probably due to lattice distortions caused by interaction between twin boundaries and fluxons. In the polycrystal, flux pinning effectiveness was seen to vary significantly between grains, depending on size and orientation. Grains with the c axis nearly perpendicular to the applied magnetic field were most effective at pinning flux. Some features of the decoration patterns implied that the flux distribution was influenced by more than just the grains at the sample surface. 7 refs., 6 figs.

Differentiating characteristics of magnetic confinement systems having externally generated magnetic fields that are open'' are listed and discussed in the light of their several potential advantages for fusion power systems. It is pointed out that at this stage of fusion research high-Q'' (as deduced from long energy confinement times) is not necessarily the most relevant criterion by which to judge the potential of alternate fusion approaches for the economic generation of fusion power. An example is given of a hypothetical open-geometry fusion power system where low-Q operation is essential to meeting one of its main objectives (low neutron power flux).

Transient electrical potentials can be generated in plasmas by utilizing impulsive mirror-generated forces acting on the plasma electrons together with ion inertia to cause momentary charge imbalance. In the Mirrortron such potentials are generated by applying a rapidly rising (tens of nanoseconds) localized mirror field to the central region of a hot-electron plasma confined between static mirrors. Because of the loss-cone nature of the electron distribution the sudden appearance of the pulsed mirror tends to expel electrons, whereas the ion density remains nearly constant. The quasi-neutrality condition then operates to create an electrical potential the equipotential surfaces of which can be shown theoretically to be congruent with surfaces of constant B. An alternative way of generating transient potentials is to apply a pulse of high-power microwaves to a plasma residing on a magnetic field with a longitudinal gradient. This technique resembles one employed in the Pleiade experiments. At gigawatt power levels, such as those produced by a Free Electron Laser, the production of very high transient potentials is predicted. Fusion-relevant applications of these ideas include heavy-ion drivers for inertial fusion, and the possibility of employing these techniques to enhance the longitudinal confinement of fusion plasmas in multiple-mirror systems. 23 refs., …

Differential-algebraic equation (DAE) boundary value problems arise in a variety of applications, including optimal control and parameter estimation for constrained systems. In this paper we survey these applications and explore some of the difficulties associated with solving the resulting DAE systems. For finite difference methods, the need to maintain stability in the differential part of the system often necessitates the use of methods based on symmetric discretizations. However, these methods can suffer from instability and loss of accuracy when applied to certain DAE systems. We describe a new class of methods, Projected Implicit Runge-Kutta Methods, which overcomes these difficulties. We give convergence and stability results, and present numerical experiments which illustrate the effectiveness of the new methods. 20 refs., 1 tab.