In today's commercially available counter-select-grade CdZnTe crystals for radiation detector applications, the thermal ionization energies of the traps and their types, whether electron or hole traps, were measured. The measurements were successfully done using thermoelectric emission spectroscopy (TEES) and thermally stimulated conductivity (TSC). For reliability, the electrical contacts to the sample were found to be very important and, instead of Au Schottky contacts, In Ohmic contacts had to be used. For the filling of the traps, photoexcitation was done at zero bias, at 20K and at wavelengths which gave the maximum bulk photoexcitation for the sample. Between the temperature range from 20 to 400 K, the TSC current was found to be on the order of {approximately} 10,000 times or even larger than the TEES current, in agreement with theory, but only TEES could resolve the trap type and was sensitive to the deep traps. Large concentration of hole traps at 0.1 and 0.6 eV were observed and smaller contraction of electron traps at 0.4 eV was seen. These deep traps cause compensation in the material and also cause trapping that degrades the radiation detection measurement.

We study dynamical flavor symmetry breaking in the context of a class of N=1 supersymmetric SU(n_c) and USp(2 n_c) gauge theories, constructed from the exactly solvable N=2 theories by perturbing them with small adjoint and generic bare hypermultiplet (quark) masses. We find that the flavor U(n_f) symmetry in SU(n_c) theories is dynamically broken to $U(r)\times U(n_f-r)$ groups for $n_f \leq n_c$. In the r=1 case the dynamical symmetry breaking is caused by the condensation of monopoles in the $\underlinen_f$ representation. For general r, however, the monopoles in the $\underline_n_fC_r$ representation, whose condensation could explain the flavor symmetry breaking but would produce too-many Nambu--Goldstone multiplets, actually"break up'' into"magnetic quarks'' which condense and induce confinement and the symmetry breaking. In USp(2n_c) theories with $n_f\leq n_c + 1$, the flavor SO(2n_f) symmetry is dynamically broken to U(n_f), but with no description in terms of a weakly coupled local field theory. In both SU(n_c) and USp(2 n_c) theories, with larger numbers of quark flavors, besides the vacua with these properties, there exist also vacua with no flavor symmetry breaking.

Device simulations of (1) the laterally-contacted-unipolar-nuclear detector (LUND), (2) the SpectrumPlus, (3) and the coplanar grid made of Cd{sub 0.9}Zn{sub 0.1}Te (CZT) were performed for {sup 137}Cs irradiation by 662.15 keV gamma-rays. Realistic and controlled simulations of the gamma-ray interactions with the CZT material were done using the MCNP4B2 Monte Carlo program, and the detector responses were simulated using the Sandia three-dimensional multielectrode simulation program (SandTMSP). The simulations were done for the best and the worst expected carrier nobilities and lifetimes of currently commercially available CZT materials for radiation detector applications. For the simulated unipolar devices, the active device volumes were relatively large and the energy resolutions were fairly good, but these performance characteristics were found to be very sensitive to the materials properties. The internal electric fields, the weighting potentials, and the charge induced efficiency maps were calculated to give insights into the operation of these devices.

Optical properties of Cd{sub 0.9}Zn{sub 0.1}Te (CZT) were studied by variable angle spectroscopic ellipsometry (VASE). Measurements made by VASE were performed on CZT and CdTe samples in air at room temperature at multiple angles of incidence. A parametric function model was employed in the VASE analysis to determine the dielectric functions {var_epsilon}={var_epsilon}{sub 1} + i{var_epsilon}{sub 2} in the range of 0.75 to 6.24 eV. A two-oscillator analytical model was used to describe the dielectric response of native oxides on CZT. Surface oxide optical properties and thickness on CZT were also determined in conjunction with the VASE measurement and analysis of a CdTe sample. Two samples of CZT of different oxide thicknesses were measured and their optical constants were coupled together in a multiple-sample, multiple-model VASE analysis to resolve correlations between fitting parameters. Effective medium approximation (EMA) was used to describe the optical properties of the CZT oxide with roughness. A Kramers-Kronig self-consistency check of the real and imaginary parts of the Cd{sub 0.9}Zn{sub 0.1} dielectric functions was performed over the energy range 0.75 to 6.24 eV. A five-Lorentz-oscillator model was employed to describe the dielectric response of CZT in the range of 1.6 to 6.24 eV. Intensity transmission measurements were …

In this paper, we compare the effectiveness of three preconditioning strategies in simulations of variably saturated flow. Using Richards' equation as our model, we solve the nonlinear system using a Newton-Krylov method. Since Krylov solvers can stagnate, resulting in slow convergence, we investigate different strategies of preconditioning the Jacobian system. Our work uses a multigrid method to solve the preconditioning systems, with three different approximations to the Jacobian matrix. One approximation lags the nonlinearities, the second results from discarding selected off-diagonal contributions, and the third matrix considered is the full Jacobian. Results indicate that although the Jacobian is more accurate, its usage as a preconditioning matrix should be limited, as it requires much more storage than the simpler approximations. Also, simply lagging the nonlinearities gives a preconditioning matrix that is almost as effective as the full Jacobian but much easier to compute.

A program has been initiated for the purpose of developing the chemical separations technologies necessary to support a large Accelerator Transmutation of Waste (ATW) system capable of dealing with the projected inventory of spent fuel from the commercial nuclear power stations in the United States. The first several years of the program will be directed toward an elucidation of related technical issues and to the establishment, by means of comprehensive trade studies, of an optimum configuration of the elements of the chemical processing infrastructure required for support of the total ATW system. By adopting this sort of disciplined systems engineering approach, it is expected that development and demonstration costs can be minimized and that it will be possible to deploy an ATW system that is an environmentally sound and economically viable venture.

The Solenoidal Tracker At RHIC (STAR) is a large acceptance collider detector, commissioned for operation at Brookhaven National Laboratory in 1999. STAR is designed to measure the momentum and identify several thousands of particles per event. About 300 Terabytes of data will be generated each year. To handle such a huge amount of data, sophisticated data structures and associated tools were developed. The main features of these data structures are: Data structure is a complicated but flexible set of C++ objects; All data objects are persistent, we do not maintain separate transient and persistent data structures; Persistence of data structure is based on ROOT[?] I/O implementation; Part of ROOT I/O was modified to meet STAR requirements; and The modification of ROOT I/O allows to support automatic schema evolution of STAR data structures. Automatic tools allow reading of old data into new environments. In this paper we present our experience with maintenance of big and complicated OO data structures, especially concerning schema evolution.

Electrical characteristics of hybrid power sources consisting of Li-ion cells and double-layer capacitors were studied at 25 C and {minus}20 C. The cells were initially evaluated for pulse performance and then measured in hybrid modes of operation where they were coupled with the high-power capacitors. Cells manufactured by Panasonic measured at 25 C delivered full capacities of 0.76 Ah for pulses up to 3A and cells from A and T delivered full capacities of 0.73 Ah for pulses up to 4A. Measured cell resistances were 0.15 ohms and 0.12 ohms, respectively. These measurements were repeated at {minus}20 C. Direct coupling of the cells and capacitors (coupled hybrid) using 10F Panasonic capacitors in a 8F series/parallel combination extended the full capacity pulse limits (3.0V threshold) to 5.6A for the Panasonic cells and to 9A for the A and T cells. A similar arrangement using 100F capacitors from Elna in a 60F combination increased the Panasonic cell limit to 10 A. Operation in an uncoupled hybrid mode using uncoupled cell/capacitor discharge allowed fill cell capacity usage at 25 C up to the capacitor discharge limit and showed a factor of 5 improvement in delivered capacity at {minus}20 C.

To minimize the viscous flow losses in a microsystem for chemical analysis, the authors have investigated gas flow in long capillary tubes and microchannels to characterize the flow behavior. Both experimental results and theoretical predictions indicate that gas flow in long and narrow channels, as in capillary tubes or rectangular channels, compressibility effect is very important. This leads to a higher mass flow rate than predicted by the incompressible flow model. Different computational fluid dynamics (CFD) codes have been applied to simulate this flow problem. While some existing CFD codes have difficulties to model this problem, other codes, such as MPSalsa, predict a converged and reasonably accurate solution. This difficulty may be caused by numerical solution technique in these computer codes being optimized for incompressible flow problems rather than for compressible low-speed flow problems.

The Solenoidal Tracker At RHIC (STAR) is a large acceptance collider detector, at Brookhaven National Laboratory. Most of the detailed knowledge on the STAR detector is implemented into a GEANT3 based simulation model. This knowledge certainly is valuable for the new STAR OO software. STAR ROOT-based framework was upgraded to provide tools to access this model via a set of TVolume classes. In this paper we present our experience with migration of the GEANT3 based detector simulation for STAR to an OO model.

This multidisciplinary team approach to waste container handling, developed within the Grassroots Ergonomics process, presents participatory ergonomic interpretations of quantitative and qualitative aspects of this process resulting in a peer developed training. The lower back, shoulders, and wrists were identified as frequently injured areas, so these working postures were a primary focus for the creation of the workers' training. Handling procedures were analyzed by the team to identify common cycles involving one 5 gallon (60 pounds), two 5 gallons (60 and 54 pounds), 30 gallon (216 pounds), and 55 gallon (482 pounds) containers: lowering from transporting to/from transport vehicles, loading/unloading on transport vehicles, and loading onto pallet. Eleven experienced waste container handlers participated in this field analysis. Ergonomic exposure assessment tools measuring these field activities included posture analysis, posture targeting, Lumbar Motion Monitor{trademark} (LMM), and surface electromyography (sEMG) for the erector spinae, infraspinatus, and upper trapezius muscles. Posture analysis indicates that waste container handlers maintained non-neutral lower back postures (flexion, lateral bending, and rotation) for a mean of 51.7% of the time across all activities. The right wrist was in non-neutral postures (radial, ulnar, extension, and flexion) a mean of 30.5% of the time and the left wrist 31.4%. Non-neutral …

Short pulse laser damage and ablation of amorphous, diamond-like carbon films is investigated. Material removal is due to fracture of the film and ejection of large fragments, which exhibit a broadband emission of microsecond duration.

Sol-gel processing of materials is plagued by shrinkage during polymerization of the alkoxide monomers and processing (aging and drying) of the resulting gels. The authors have developed a new class of hybrid organic-inorganic materials based on the solventless ring-opening polymerization (ROP) of monomers bearing the 2,2,5,5-tetramethyl-2,5-disilaoxacyclopentyl group, which permits them to drastically reduce shrinkage in sol-gel processed materials. Because the monomers are polymerized through a chain growth mechanism catalyzed by base rather than the step growth mechanism normally used in sol-gel systems, hydrolysis and condensation products are entirely eliminated. Furthermore, since water is not required for hydrolysis, an alcohol solvent is not necessary. Monomers with two disilaoxacyclopentyl groups, separated by a rigid phenylene group or a more flexible alkylene group, were prepared through disilylation of the corresponding diacetylenes, followed by ring closure and hydrogenation. Anionic polymerization of these materials, either neat or with 2,2,5,5-tetramethyl-2,5-disila-1-oxacyclopentane as a copolymer, affords thermally stable transparent gels with no visible shrinkage. These materials provide an easy route to the introduction of sol-gel type materials in encapsulation of microelectronics, which they have successfully demonstrated.

The Solenoidal Tracker At RHIC (STAR) is a-large acceptance collider detector, commissioned at Brookhaven National Laboratory in 1999. STAR has developed a software framework supporting simulation, reconstruction and analysis in offline production, interactive physics analysis and online monitoring environments that is well matched both to STAR's present status of transition between Fortran and C++ based software and to STAR's evolution to a fully OO software base. This paper presents the results of two years effort developing a modular C++ framework based on the ROOT package that encompasses both wrapped Fortran components (legacy simulation and reconstruction code) served by IDL-defined data structures, and fully OO components (all physics analysis code) served by a recently developed object model for event data. The framework supports chained components, which can themselves be composite subchains, with components (''makers'') managing ''data sets'' they have created and are responsible for. An St-DataSet class from which data sets and makers inherit allows the construction of hierarchical organizations of components and data, and centralizes almost all system tasks such as data set navigation, I/O, database access, and inter-component communication. This paper will present an overview of this system, now deployed and well exercised in production environments with real and …

Differential scanning calorimetry (DSC) analysis was used to identify thermal reactions in Sony-type lithium-ion cells and to correlate these reactions with interactions of cell constituents and reaction products. An electrochemical half-cell was used to cycle the anode and cathode materials and to set the state-of-charge (SOC). Three temperature regions of interaction were identified and associated with the SOC (degree of Li intercalation) of the cell. Anodes were shown to undergo exothermic reactions as low as 80 C involving decomposition of the solid electrolyte interphase (SEI) layer. The LiPF{sub 6} salt in the electrolyte (EC:PC:DEC/1M LiPF{sub 6}) was seen to play an essential role in this reaction. DSC analysis of the anodes from disassembled Sony cells showed similar behavior to the half-cell anodes with a strong exotherm beginning in the 80 C--90 C range. Exothermic reactions were also observed in the 200 C--300 C region between the intercalated lithium anodes, the LiPF{sub 6} salt, and the PVDF binder. These reactions were followed by a high-temperature reaction region, 300 C--400 C, also involving the PVDF binder and the intercalated lithium anodes. Cathode exothermic reactions with the PVDF binder were observed above 200 C and increased with the SOC (decreasing Li content in …

A computer model for systems analysis of heavy ion drivers has been developed and used to evaluate driver designs for inertial fusion energy (IFE). The present work examines a driver for a close-coupled target design that requires less total beam energy but also smaller beam spots sizes than previous target designs. Design parameters and a cost estimate for a 160 beam, 3.3 MJ driver using rubidium ions (A = 85) are reported, and the sensitivity of the results to variations in selected design parameters is given.

The change in software language and methodology by CDF and D0 to object-oriented from procedural Fortran is significant. Both experiments requested dedicated expertise that could be applied to software design, coding, advice and review. The Fermilab Run II offline computing outside review panel agreed strongly with the request and recommended that the Fermilab Computing Division hire dedicated OO expertise for the CDF/D0/Computing Division joint project effort. This was done and the two experts have been an invaluable addition to the CDF and D0 upgrade software projects and to the Computing Division in general. These experts have encouraged common approaches and increased the overall quality of the upgrade software. Advice on OO techniques and specific advice on C++ coding has been used. Recently a set of software reviews has been accomplished. This has been a very successful instance of a targeted application of computing expertise, and constitutes a very interesting study of how to move toward modern computing methodologies in HEP.

Detailed measurements of CP violation in B meson decay are on the horizon. Here the author reviews the status of current measurements of sin 2{beta} made at LEP and CDF. These yield an average of sin 2{beta} = 0.82 {+-} 0.39, giving 97% confidence that {beta} is greater than 0, evidence that CP violation occurs in B decay. He reviews predictions for the precision one can expect on sin 2{beta} and sin 2{alpha} in the next few years.

Experiments are being prepared at the Fermilab Tevatron and the CERN Large Hadron Collider that promise to deliver extraordinary insights into the nature of spontaneous symmetry breaking, and the role of supersymmetry in the universe. This article reviews the goals, challenges, and designs of these experiments. The first hadron collider, the ISR at CERN, has to overcome two initial obstacles. The first was low luminosity, which steadily improved over time. The second was the broad angular spread of interesting events. In this regard Maurice Jacob noted (1): The answer is ... sophisticated detectors covering at least the whole central region (45{degree} {le} {theta} {le} 135{degree}) and full azimuth. This statement, while obvious today, reflects the major revelation of the ISR period that hadrons have partonic substructure. The result was an unexpectedly strong hadronic yield at large transverse momentum (p{sub T}). Partly because of this, the ISR missed the discovery of the J/{psi} and later missed the {Upsilon}. The ISR era was therefore somewhat less auspicious than it might have been. It did however make important contributions in areas such as jet production and charm excitation and it paved the way for the SPS collider, also at CERN.

In this paper we present results from the measurement of the gamma ray yield in the reaction of 34-MeV protons on Cu, Ag and Au. The protons were produced by the University of Washington superconducting linac. The gamma rays were measured using a large NaI and two large BaF{sub 2} detectors. Angular distributions were obtained for each of the three targets. Data for the Cu and Ag target were taken at six lab angles between 35 and 135 degrees, while data were taken at eight lab angles between 35 and 135 degrees for the Au target. The data were compared to several models. These included Hauser-Feshbach and direct-semidirect (DSD) calculations. We also compared the measurements to proton-nucleus bremsstrahlung calculations. The bremsstrahlung calculations greatly underpredicted the cross section and produced an angular distribution which was too flat. The Hauser-Feshbach calculations reproduced the yield of the softer portion of the spectrum reasonably well for all three targets. The DSD calculations reproduced the yield and angular distributions quite well for energies above about 20 MeV. However, the yields were underpredicted in the 15-18 MeV region, which suggests that multistep mechanisms may be needed for this target.

Lawrence Livermore National Laboratory (LLNL) has conducted design and testing activities of the Nondestructive Assay/Evaluation (NDA/NDE) system that will be installed to support the Plutonium Ceramification Test Facility (PuCTF). PuCTF immobilizes plutonium using the ceramic can-in-canister technology. The overall function of the NDA/NDE System is to ensure that sintered pucks contain the appropriate materials for ceramification process control, special nuclear materials (SNM) accountability, and repository acceptance. The system accepts sample pucks from the ceramification system, performs measurements, and determines if the product pucks are acceptable. This report details the conceptual system that is being developed.

The ultimate goal of the Department of Energy (DOE) Immobilization Project is to develop, construct, and operate facilities that will immobilize between 17 to 50 tonnes (MT) of U.S. surplus weapons-usable plutonium materials in waste forms that meet the ''spent fuel'' standard and are acceptable for disposal in a geologic repository. Using the ceramic can-in-canister technology selected for immobilization, surplus plutonium materials will be chemically combined into ceramic forms which will be encapsulated within large canisters of high level waste (HLW) glass. Deployment of the immobilization capability should occur by 2008 and be completed within 10 years. In support of this goal, the DOE Office of Fissile Materials Disposition (MD) is conducting development and testing (D&T) activities at four DOE laboratories under the technical leadership of Lawrence Livermore National Laboratory (LLNL). The Savannah River Site has been selected as the site for the planned Plutonium Immobilization Plant (PIP). The D&T effort, now in its third year, will establish the technical bases for the design, construction, and operation of the U. S. capability to immobilize surplus plutonium in a suitable and cost-effective manner. Based on the D&T effort and on the development of a conceptual design of the PIP, automation is …

Useful products generated from interferometric synthetic aperture radar (IFSAR) complex data include height measurement, coherent change detection, and classification. The IFSAR coherence is a spatial measure of complex correlation between two collects, a product of IFSAR signal processing. A tacit assumption in such IFSAR signal processing is that one height target exists in each range-Doppler cell. This paper presents simulations of IFSAR coherence if two targets with different heights exist in a given range-Doppler cell, a condition in IFSAR collections produced by layover. It also includes airborne IFSAR data confirming the simulation results. The paper concludes by exploring the implications of the results on IFSAR classification and height measurements.

The authors describe a method for designing the acceleration systems for a muon collider, with particular application and examples for a high energy muon collider. This paper primarily concentrates on design considerations coming from longitudinal motion, but some transverse issues are briefly discussed.