Recent advances in solid-state modulators now permit the design of a new class of high current accelerators. These new accelerators will be able to operate in burst mode at frequencies of several MHz with unprecedented flexibility and precision in pulse format. These new modulators can drive accelerators to high average powers that far exceed those of any other technology and can be used to enable precision beam manipulations. New insulator technology combined with novel pulse forming lines and switching may enable the construction of a new type of high gradient, high current accelerator. Recent developments in these areas will be reviewed.

We consider the case of several scalar fields, charged under a number of U(1) factors, acquiring vacuum expectation values due to anomalous U(1). We demonstrate how to make redefinitions at the superfield level in order to account for tree-level exchange of vector supermultiplets in the effective supergravity theory of the light fields in the supersymmetric vacuum phase. Our approach builds up on previous results that we obtained in a more elementary case. We find that the modular weights of light fields are typically shifted from their original values, allowing an interpretation in terms of the preservation of modular invariance in the effective theory. We address various subtleties in defining unitary gauge that are associated with the noncanonical Kahler potential of modular invariant supergravity, the vacuum degeneracy, and the role of the dilaton field. We discuss the effective superpotential for the light fields and note how proton decay operators may be obtained when the heavy fields are integrated out of the theory at the tree-level. We also address how our formalism may be extended to describe the generalized Green-Schwarz mechanism for multiple anomalous U(1)'s that occur in four-dimensional Type I and Type IIB string constructions.

The possibility to use various target materials are studied for a 2 MW neutrino superbeam facility that can be built at Fermilab utilizing the Main Injector and a Proton Driver. A simple target solution found is a thick graphite rod taking a broad proton beam.

There are four important factors which influence the magnitude of the magnetic heat capacity near the magnetic ordering transition temperature. These include the theoretical magnetic entropy, the deGennes factor, crystalline electric field, and the RKKY (Ruderman-Kittel-Kasuya-Yosida) interaction. The lattice contribution to the heat capacity also needs to be considered since it is the sum of the lattice and magnetic contributions which give rise to the heat capacity maxima. The lattice heat capacity depends on the chemical composition, crystal structure and temperature. As a result, one can obtain large changes in the heat capacity maxima by alloying. Several ternary intermetallic systems have been examined in light of these criteria. A number of deviations from the expected behaviors have been found and are discussed.

The presence of actinides in spent fuel destined for a geologic repository such as the proposed Yucca Mountain Repository causes a substantial long term heat load, causes the radiotoxicity of the waste to remain high for tens of thousands of years, and contributes significantly to the long-term dose rate once waste packages begin to fail. Examples, mostly based on the current design of the proposed repository, are considered to illustrate the potential impact of actinide removal on each of these factors. The analyses show that removal of 90 to 99% of the actinides may significantly increase in the capacity of a repository. In addition, the radiotoxicity of the waste may be reduced to a value less than that of the uranium ore from which the fuel was manufactured within the 10,000-year regulatory period. For example, removal of 99.9% of the actinides reduces the radiotoxicity to a level less than that of the original ore in less than 400 years. Finally, removal of 99% of the actinides could reduce the peak long-term dose rate, estimated to occur after about 270,000 years, by as much as a factor of 60.

The structural transformations that occur in diamondlike carbon coatings with increasing hydrogen content have been investigated by Raman spectroscopy, transmission electron microscopy, electron diffraction, and electron-energy-loss spectroscopy. Friction tests were performed with uncoated steel balls against coated substrates at contact stresses of 1 GPa in ambient air (relative humidity = 30 - 40%), dry air (relative humidity < 1%), and dry nitrogen (< 1%). The lowest friction coefficient (f < 0.02) was obtained for the most hydrogenated sample in dry nitrogen, where the formation of a third-body layer was observed on the steel surface. Raman spectra obtained from the counterfaces after sliding in humid and dry air revealed a remarkable increase and narrowing of the ''D'' and ''G'' peaks with decreasing humidity. Analysis of peak positions and I(D)/I(G) ratios pointed to an increasing order and an enlargement of the sp{sup 2} clusters under friction. The shape and position of the carbon K-edge spectra for the transfer layer are affected the same way, although evidence of extended graphite layer formation was not observed. Development of these differing trends was correlated with the hydrogen-to-carbon ratio of the gas precursor used during the synthesis and with the type of surrounding atmosphere.

Five different experiments on thermal heating of explosive materials have been performed. Three experiments thermally exploded PBX 9501 (HMX/Estane/BDNPA-F; 9512.512.5 wt %) donor charges while two others thermally exploded LX-04 (HMX/Viton A; 85/15 wt %). These donor charges were encased in 304 stainless steel. The transmitted two-dimensional pressure waves were measured by gauges in acceptor cylinders of Teflon, PBX 9501, or LX-04 that were in contact with the donors' steel case. A fifth experiment measured the pressure in an acceptor charge of PBX 9501 that had a 100 mm stand-off from the top of the steel case of the thermally cooked off PBX 9501 donor charge. Reactive flow hydrodynamic modeling using a rapid deflagration velocity of approximately 500 m/s was able to reproduce the pressure gauge records for both the in contact and stand off experiments that used PBX 9501 donors and acceptors.

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A series of batch heatup experiments and a limited set of continuous data studies have provided qualitative evidence that several mechanisms for hydrogen production other than simple real-time radiolysis are causing unexpectedly high hydrogen emissions from some drums of transuranic solidified organic wastes.