An all solid-state kicker pulser for a high current induction accelerator (the Dual-Axis Radiographic Hydrodynamic Test facility DARHT-2) has been designed and fabricated. This kicker pulser uses multiple solid state modulators stacked in an inductive-adder configuration. Each modulator is comprised of multiple metal-oxide-semiconductor field-effect transistors (MOSFETs) which quickly switch the energy storage capacitors across a magnetic induction core. Metglas is used as the core material to minimize loss. Voltage from each modulator is inductively added by a voltage summing stalk and delivered to a 50 ohm output cable. A lumped element circuit model of the inductive adder has been developed to optimize the performance of the pulser. Results for several stalk geometries will be compared with experimental data.

The Inner and Outer modules of the Central Solenoid Model Coil (CSMC) were built by US and Japanese home teams in collaboration with European and Russian teams to demonstrate the feasibility of a superconducting Central Solenoid for ITER and other large tokamak reactors. The CSMC mass is about 120 t, OD is about 3.6 m and the stored energy is 640 MJ at 46 kA and peak field of 13 T. Testing of the CSMC and the CS Insert took place at Japan Atomic Energy Research Institute (JAERI) from mid March until mid August 2000. This paper presents the main results of the tests performed.

We present results from the Sustained Spheromak Physics Experiment (SSPX) at LLNL, which has been built to study energy confinement in spheromak plasmas sustained for up to 2 ms by coaxial DC helicity injection. Peak toroidal currents as high as 600kA have been obtained in the 1m dia. (0.23m minor radius) device using injection currents between 200-400kA; these currents generate edge poloidal fields in the range of 0.2-0.4T. The internal field and current profiles are inferred from edge field measurements using the CORSICA code. Density and impurity control is obtained using baking, glow discharge cleansing, and titanium gettering, after which long plasma decay times ({tau} {ge} 1.5ms) are observed and impurity radiation losses are reduced from {approx}50% to <20% of the input energy. Thomson scattering measurements show peaked electron temperature and pressure profiles with T{sub e} (0){approx}120eV and {beta}{sub e}{approx}7%. Edge field measurements show the presence of n=1 modes during the formation phase, as has been observed in other spheromaks. This mode dies away during sustainment and decay so that edge fluctuation levels as low as 1% have been measured. These results are compared with numerical simulations using the NIMROD code.

Initial measurements are reported for the Mercury laser system, a scalable driver for rep-rated high energy density physics research. The performance goals include 10% electrical efficiency at 10 Hz and 100 J with a 2-10 ns pulse length.

A thick flowing layer of liquid (e.g., flibe-a molten salt, or Sn{sub 80}Li{sub 20}--a liquid metal) protects the structural walls of the magnetic fusion configuration so that they can last the life of the plant even with intense 14 MeV neutron bombardment from the D-T fusion reaction, The surface temperature of the liquid rises as it passes from the inlet nozzles to the exit nozzles due to absorption of line and bremsstrahlung radiation, and neutrons. The surface temperature can be reduced by enhanced turbulent convection of hot surface liquid into the cooler interior. This surface temperature is affected by the temperature of liquid from a heat transport and energy recovery system. The evaporative flux from the wall driven by the surface temperature must also result in an acceptable impurity level in the core plasma. The shielding of the core by the edge plasma is modeled with a 2D-transport code for the DT and impurity ions; these impurity ions are either swept out to the divertor, or diffuse to the hot plasma core. An auxiliary plasma between the edge plasma and the liquid wall may further attenuate evaporating flux of atoms and molecules by ionization near the wall.

PVODE is a high-performance ordinary differential equation solver for the types of initial value problems (IVPs) that arise in large-scale computational simulations. often, one wants to compute sensitivities with respect to certain parameters in the IVP. They discuss the use of automatic differentiation (AD) to compute these sensitivities in the context of PVODE. Results on a simple test problem indicate that the use of AD-generated derivative code can reduce the time to solution over finite difference approximations.

The DARHT TI accelerator uses a pulsed high current electron beam and Eiremsstrahlung converter target to generate an intense x-ray source for radiography. For the past several years, we have been performing an investigation of the possible adverse effects of (1) backstreaming ion emission from the Bremsstrahlung converter target and (2) the interaction of the resultant plasma with the electron beam during subsequent pulses. These effects would manifest themselves in a static focusing system as a rapidly varying x-ray spot. To study these effects, we are conducting beam-target interaction experiments on the ETA-I1 accelerator (a 6.0 MeV, 2.5 kA, 70 ns FWHM pulsed induction LINAC). We have determined spot dynamics and characterized the resultant plasma for various configurations. Our experiments show that the first effect is not strongly present when the beam initially interacts with the target. Electron beam pulses delivered to the target after formation of a plasm are strongly affected, however. We have also performed initial experiments to determine the effect of the beam propagating through the plasma. This data shows that the head of the beam is relatively robust, but that backstreaming ions from the plasma can induce a dynamic focus toward the tail of the beam. …

A new method for the solution of the unsteady Euler equations has been developed. The method combines staggered grid Lagrangian techniques with structured local adaptive mesh refinement (AMR). This method is a precursor to a more general adaptive arbitrary Lagrangian Eulerian (ALE-AMR) algorithm under development, which will facilitate the solution of problems currently at and beyond the boundary of soluble problems by traditional ALE methods by focusing computational resources where they are required. Many of the core issues involved in the development of the ALE-AMR method hinge upon the integration of AMR with a Lagrange step, which is the focus of the work described here. The novel components of the method are mainly driven by the need to reconcile traditional AMR techniques, which are typically employed on stationary meshes with cell-centered quantities, with the staggered grids and grid motion employed by Lagrangian methods. These new algorithmic components are first developed in one dimension and are then generalized to two dimensions. Solutions of several model problems involving shock hydrodynamics are presented and discussed.

We describe a coded aperture, gamma-ray imager which uses a CsI(Na) scintillator coupled to an Hamamatsu R3292 position-sensitive photomultiplier tube (PSPMT) as the position-sensitive detector. We have modified the normal resistor divider readout of the PSPMT to allow use of nearly the full 10 cm diameter active area of the PSPMT with a single scintillator crystal one centimeter thick. This is a significant performance improvement over that obtained with the standard readout technique where the linearity and position resolution start to degrade at radii as small as 3.5 cm with a crystal 0.75 crn thick. This represents a recovery of over 60% of the PSPMT active area. The performance increase allows the construction of an imager with a field of view 20 resolution elements in diameter with useful quantum efficiency from 60-700 keV. In this paper we describe the readout technique, its implementation in a coded aperture imager and the performance of that imager.

The goal of this joint LLNL-CalEnergy project is to develop a method for precipitating marketable silica from spent Salton Sea Geothermal Field (SSGF) brines. Many markets for silica exist. We have initially targeted production of silica as a rubber additive. Silica reinforced rubber gives tires less rolling resistance, greater tear strength, and better adhesion to steel belts. Previous silica precipitates produced by CalEnergy from Salton Sea brines were not suitable as rubber additives. They did not to disperse well in the rubber precursors and produced inferior rubber. CalEnergy currently minimizes silica scaling in some of their production facilities by acidifying the brine pH. The rate of silica precipitation slows down as the pH is lowered, so that energy extraction and brine reinfection are possible without unacceptable amounts of scaling even with more than 700 ppm SiO{sub 2} in solution. We are adding a step in which a small amount of base is added to the acidified brine to precipitate silica before reinfection. By carefully controlling the type, rate, and amount of base addition, we can optimize the properties of the precipitate to approach those of an ideal rubber additive.

A common coil design for a high-field accelerator dipole magnet using a Nb{sub 3}Sn cable with the React-and-Wind approach is pursued by a collaboration between Fermilab and LBNL. The design requirements for the cable include a high operating current so that a field of 10-11 T can be produced, together with a low critical current degradation due to bending around a 90 mm radius. A program, using ITER strands of the internal tin type, was launched to develop the optimal cable design for React-and-Wind common coil magnets. Three prototype cable designs, all 15 mill wide, were fabricated: a 41-strand cable with 0.7 mm diameter strands; a 57-strand cable with 0.5 mm diameter strands; and a 259 strand multi-level cable with a 6-around-1 sub-element using 0.3 mm diameter wire. Two versions of these cables were fabricated: one with no core and one with a stainless steel core. Additionally, the possibility of a wide (22 mm) cable made from 0.7 mm strand was explored. This paper describes the first results of the cable program including reports on cable fabrication and reaction, first winding tests and first results of the measurement of the critical current degradation due to cabling and bending.

The magnet group at LBNL is currently in the process of developing high-field accelerator magnets for use in future colliders. One of the primary challenges is to provide a design which is cost-effective and simple to manufacture, at the same time resulting in good training performance and field quality adequate for accelerator operation. Recent studies have focused on a racetrack geometry that has the virtues of simplicity and conductor compatibility. The results have been applied to the design of a series of prototype high-field magnets based on Nb{sub 3}Sn conductor.

We discuss dynamics of N=2 supersymmetric SU(n_c) gaugetheories with n_f quark hypermultiplets. Upon N=1 perturbation ofintroducing a finite mass for the adjoint chiral multiplet, we show thatthe flavor U(n_f) symmetry is dynamically broken to U(r) times U(n_f-r),where r\leq [n_f/2]is an integer. This flavor symmetry breaking occursdue to the condensates of magnetic degrees of freedom which acquireflavor quantum numbers due to the quark zero modes. We briefly comment onthe USp(2n_c) gauge theories. This talk is based on works with GiuseppeCarlino and Ken Konishi, hep-th/0001036 and hep-th/0005076.

We advocate a new approach to study models of fermion massesand mixings, namely anarchy proposed in hep-ph/9911341. In this approach,we scan the O(1) coefficients randomly. We argue that this is the correctapproach when the fundamental theory is sufficiently complicated.Assuming there is no physical distinction among three generations ofneutrinos, the probability distributions in MNS mixing angles can bepredicted independent of the choice of the measure. This is because themixing angles are distributed according to the Haar measure of the Liegroups whose elements diagonalize the mass matrices. The near-maximalmixings, as observed in the atmospheric neutrino data and as required inthe LMA solution to the solar neutrino problem, are highly probable. Asmall hierarchy between the Delta m2 for the atmospheric and the solarneutrinos is obtained very easily; the complex seesaw case gives ahierarchy of a factor of 20 as the most probable one, even though thisconclusion is more measure-dependent. U_e3 has to be just below thecurrent limit from the CHOOZ experiment. The CP-violating parameter sindelta is preferred to be maximal. We present a simple SU(5)-likeextension of anarchy to the charged-lepton and quark sectors which workswell phenomenologically.

A protocol has been developed for use in the disposition of concrete from Decontamination and Decommissioning (D&D) projects. The purpose of this protocol is to assist U.S. Department of Energy (DOE) sites in releasing concrete for re-use within the DOE complex. Current regulations allow sites to release surface-contaminated materials if they contain very low amounts of radioactivity and to possibly release materials with volumetric contamination, or higher levels of surface contamination on a case-bycase basis. In all cases, an ALARA (as low as reasonably achievable) analysis that evaluates the risks of releasing volumetrically contaminated concrete or concrete with higher levels of surface contamination, is required. To evaluate the dose impacts of re-using radioactively contaminated material, the measured radiation levels (pCi/g or disintegrations per minute (dpm)/100 cm2) must be converted to the estimated dose (mrem/yr) that would be received by affected individuals. The dose depends on the amounts and types of isotopes present and the time, distance, and method of exposure (e.g., inhalation or external exposure). For each disposition alternative, the protocol provides a systematic method to evaluate the impact of the dose on affected individuals. The cost impacts of re-using concrete also need to be evaluated. They too depend on …

An experimental and calculational study has been performed to understand and prevent inadvertent activation of the criticality alarm system (CAS) from fuel-handling operations at the Irradiated Fuel Storage Facility. In conjunction with the study, the CAS neutron detectors were tested to verify the design specifications for gamma rejection capability and zero response limit. A minimum physical restrictive boundary around the CAS location was established based on a gamma ray dose rate limit of 10 rad/hr. The canister loaded with spent nuclear fuel must be moved in the area outside the exclusion zone so as not to trigger a false alarm from the CAS detectors.

It is time to reconsider entombment of nuclear reactors and other facilities. Decommissioning worker exposure and safety, transportation, cost, potential loss of LLW disposal capacity, and need for strong technical basis are shared drivers for the renewed interest in developing the entombment D&D option. Entombment relies on retarding the release of radionuclides for a very long period, a number of factors must be considered prior to selection and implementation of entombment. A technical basis for addressing and evaluating these factors with associated stakeholder acceptance of the technology is needed before entombment becomes an accepted D&D option.

Investigators at the Idaho National Engineering and Environmental Laboratory (INEEL) are developing technologies that will enhance the feasibility of generating electrical power from a hydrothermal resource. One of the concepts investigated is the use of modified inlet conditions in geothermal binary power plant turbines to increase the power generation. An inlet condition of interest allows the expanding vapor to enter the two-phase region, a mode of operation typically avoided because of concern that condensate would form and damage the turbine, degrading performance. INEEL investigators postulated that initially a supersaturated vapor would be supported, and that no turbine damage would occur. This paper summarizes the investigation of these expansions that began with testing of their condensation behavior, and culminated with the incorporation of these expansions into the operation of several commercial binary plant turbines.

The technical basis and stakeholder acceptance of entombment technology is necessary before entombment becomes a decontamination and decommissioning (D&D) option for nuclear reactors. The authors present a research and development (R&D) approach addressing technical basis and stakeholder acceptance of entombment technology. The approach includes a consortium and the conceptual R&D program.

Preferential flow paths are expected in many groundwater systems and must be located because they can greatly affect contaminant transport. The fundamental characteristics of radiogenic isotope ratios in chemically evolving waters make them highly effective as preferential flow path indicators. These ratios tend to be more easily interpreted than solute-concentration data because their response to water-rock interaction is less complex. We demonstrate this approach with groundwater {sup 87}Sr/{sup 86}Sr ratios in the Snake River Plain aquifer within and near the Idaho National Engineering and Environmental Laboratory. These data reveal slow-flow zones as lower {sup 87}Sr/{sup 86}Sr areas created by prolonged interaction with the host basalts and a relatively fast flowing zone as a high {sup 87}Sr/{sup 86}Sr area.

Cleanup of the Hanford Site is currently planned to take until 2046 and another approximately $SOB. In the summer of 1999, Fluor Hanford initiated an ''Accelerated Closure Team'' to evaluate opportunities to reduce this long schedule and high cost for the parts of the Hanford Site which they manage. To-date, this breakthrough team has developed two approaches which will move > 50 million curies away from the Columbia River sooner than planned and at a significantly reduced cost. The approaches successfully applied so far are presently being applied to other opportunities at Hanford.

Work on radiological systems and components needs to be accomplished using techniques that reduce radiation dose to workers, limit contamination spread, and minimize radioactive waste. One of the best methods to control contamination spread is to use localized ventilation to capture radioactive material and keep it from spreading. The Fluor Hanford ALARA Center teaches workers how to use ventilation in partnership with other engineered controls and this has resulted in improved work practices, minimized the impact on adjacent work operations, and decreased the amount of radioactive waste generated. This presentation will emphasize how the workers are trained to use localized ventilation for contamination control.

The Lawrence Berkeley National Laboratory is preparing to upgrade the Advanced Light Source (ALS) with three superconducting dipoles (Superbends). In this paper we present the final magnet system design which incorporates R&D test results and addresses the ALS operational concerns of alignment, availability, and economy. The design incorporates conduction-cooled Nb-Ti windings and HTS current leads, epoxy-glass suspension straps, and a Gifford-McMahon cryocooler to supply steady state refrigeration. We also present the current status of fabrication and testing.

The management practices, procedures, and processes that are suited to managing Management and Operation (M&O) type of contracts at Department of Energy (DOE) sites, which were cost reimbursement with award fee, are not well suited to managing contracts where fee is determined by performance metrics. Thus a different style of management, requiring substantial revamping of the management process, is needed. This shift in philosophy also requires a dramatic shift in culture. This paper will describe how these changes are being managed at the River Protection Project (RPP), located at the DOE's Hanford Site in Washington State, one of DOE's largest and highest risk environmental clean-up project.