Exceptional progress has been made in mathematical algorithm research leading to optimized mesh partitions for the highly unstructured grids occurring in finite element applications in solid mechanics. Today another research challenge presents itself. Research is needed to include boundary conditions into the algorithms for partitioning meshes. We describe below two methods we use currently to accomplish this and propose a more general approach be developed which would apply to our problems today as well as to the coupled models we envision for the future. Finally, we suggest research be considered that would incorporate partitioning methods into parallel mesh generation.

This report presents analytical results of air samples collected from trenches at the Low Level Burial Grounds. The samples were collected with SUMMA canisters and were analyzed by gas chromatography-mass spectrometry using a modified EPA TO-14 procedure. The data suggest that the vent pipes of the 218-W-4C trenches had elevated concentrations of volatile organic compounds. The ambient air samples collected at the 218-W-5 {number_sign}31 facility, an open trench that does not contain any waste at this time, did not show any target compounds above the method detection limit.

We describe recent experiments at the Lawrence Livermore National Laboratory (LLNL) to produce a table-top x-ray laser. Using a combination of long 800 ps and short {approximately}1 ps high power laser pulses with {approximately} 6 J in each beam, a transient collisionally excited Ne-like ion x-ray laser scheme has been investigated. We present results of high x-ray laser gain for the Ne- like Ti 3p-3s J=O-l transition at 326 {Angstrom} and have achieved gL product of 15 for target lengths up to 1 cm. We have extended the transient collisional scheme to shorter wavelengths using the Ni-like analog, specifically the 4d-4p J=O-l of Ni-like Pd at 147 {Angstrom}.

This paper describes the content of an L-mode database that has been compiled with data from Alcator C-Mod, ASDEX, DIII, DIII-D, FTU, JET, JFT-2M, JT-60, PBX-M, PDX, T-10, TEXTOR, TFTR, and Tore-Supra. The database consists of a total of 2938 entries, 1881 of which are in the L-phase while 922 are ohmically heated only (OH). Each entry contains up to 95 descriptive parameters, including global and kinetic information, machine conditioning, and configuration. The paper presents a description of the database and the variables contained therein, and it also presents global and thermal scalings along with predictions for ITER.

The operational characteristics and performance of the two channel 10 Megawatt MHD feedback control system as installed by Los Alamos National Laboratory on the Columbia University HBT-EP tokamak are described. In the present configuration, driving independent 300 {micro}H saddle coil sets, each channel can deliver 1100 Amperes and 16 kV peak to peak. Full power bandwidth is about 12 kHz, with capabilities at reduced power to 30 kHz. The present system topology is designed to suppress magnetohydrodynamic activity with m=2, n=1 symmetry. Application of either static (single phase) or rotating (twin phased) magnetic perturbations shows the ability to spin up or slow down the plasma, and also prevent (or cause) so-called ''mode-locking''. Open loop and active feedback experiments using a digital signal processor (DSP) have been performed on the HBT-EP tokamak and initial results show the ability to manipulate the plasma MHD mode frequency.

This paper presents the initial electrical and mechanical design of two phase-locked 30 Megawatt RMS, 150 kHz oscillator systems used for current drive and plasma sustainment of the ''Translation, Confinement, and Sustainment'' (TCS) field reversed configuration (FRC) plasma. By the application of orthogonally-placed saddle coils on the surface of the glass vacuum vessel, the phase-controlled rotating magnetic field perturbation will induce an electric field in the plasma which should counter the intrinsic ohmic decay of the plasma, and maintain the FRC. Each system utilizes a bank of 6 parallel magnetically beamed ML8618 triodes. These devices are rated at 250 Amperes cathode current and a 45 kV plate voltage. An advantage of the magnetically beamed triode is their extreme efficiency, requiring only 2.5 kW of filament and a few amps and a few kV of grid drive. Each 3.5 uH saddle coil is configured with an adjustable tank circuit (for tuning). Assuming no losses and a nominal 18 kV plate voltage, the tubes can circulate about 30 kV and 9 kA (pk to pk) in the saddle coil antenna, a circulating power of over 33 megawatts RMS. On each cycle the tubes can kick in up to 1500 Amperes, providing a …

A small-scale demonstration of a new photocatalytic membrane reactor was undertaken at the X-623 Groundwater Treatment Facility at the Portsmouth Gaseous Diffusion Plant. The photocatalytic membrane reactor initially removed between 60 and 65% of the TCE in a single pass. It also removed significant amounts of three additional compounds (including completely removing one of the compounds). It is believed that these compounds were vinyl chloride, and two isomers of dichloroethylene. Within three days from startup, high suspended solids (mainly bacteria) contained in the feedwater tank caused plugging of the system`s prefilter. The high concentration of bacteria was the result of a previously unknown large amount of activated carbon present in the feed tank prior to addition of the groundwater. It was also later discovered that fine colloidal silt particles had fouled the photocatalytic membranes and reduced their activity yielding only about a 20% reduction of TCE. The silt particles were determined to be between 50 and 100 nm and were able to pass through the 500 nm (0.5 {mu}m) diameter pores of the prefilter. The results of this field test demonstrated the potential for success of the deployment of this technology, the simplicity, flexibility, and operability of the process and …