We have been using the 3d PIC code WARP6 to model the behavior of beams in a heavy ion induction accelerator; such linacs are candidates for an ICF driver. Improvements have been added to the code to model an axially confined beam using comoving axial electric fields to simulate the confining ears'' applied to the accelerating pulses in a real system. We have also added a facility for modeling a beam in a round pipe, applying a capacity matrix to each axial Fourier mode in turn. These additions are described along with results, such as the effect of pipe shape on the beam quality degradation from quadrupole misalignments. 5 refs., 6 figs., 1 tab.

The goal of the continuous air monitor (CAM) system at the Los Alamos National Laboratory`s Plutonium Facility (PF-4) is to have a flow rate of 1 cubic feet per minute (cfm) drawn through the CAMs. However, design limitations in the house vacuum result in many CAMs having less than 1 cfm being drawn through them. Reduced flow rates through CAMs present a compromise in worker protection. Laboratory Health and Safety personnel and DOE officials established a flow rate of 0.5 cfm or less as operationally unacceptable. This report quantitatively estimated the difference in risk to workers from a reduced flow rate of 0.5 cfm relative to the risk inherent with a flow rate of 1 cfm. I calculated risk in terms of Committed Effective Dose Equivalent (CEDE) and used units of rem. Estimates for the increase in risk for 0.5 cfm compared to 1 cfm ranged from 0.32 rem to 3.3 rem. The difference in the minimum alarm concentration between 0.5 cfm and I cfm was also compared and was estimated to range from 0.4 rem to 4 rem.

We study the structure of the moduli spaces of vacua and superpotentials of N = 2 supersymmetric gauge theories in three dimensions. By analyzing the instanton corrections, we compute the exact superpotentials and determine the quantum Coulomb and Higgs branches of the theories in the weak coupling regions. We find candidates for non-trivial N = 2 superconformal field theories at the singularities of the moduli spaces. The analysis is carried out explicitly for gauge groups U(N{sub c}) and SU(N{sub c}) with N{sub f} flavors. We show that the field theory results are in complete agreement with the intersecting branes picture. We also compute the exact superpotentials for arbitrary gauge groups and arbitrary matter content.

We could become convinced that a particular theory of very-high-energy physics is correct if (1) it has a tightly constrained structure and is linked strongly enough with observed particle interactions, or (2) it predicts new physics beyond the standard model which is discovered. The author makes the case that experiments of this decade and the next allow the possibility that we might become convinced that grand unification, a candidate theory of the second type, is correct.

The STAR experiment at RHIC is a TPC-based, general purpose detector designed to obtain charged particle spectra, with an emphasis on hadrons over a large phase space. An electromagnetic calorimeter provides measurement of e's, {gamma}'s, {pi}{sup 0}'s and jets. Data-taking with Au + Au collisions at {radical}5 = 200 GeV/c{sup 2} begins in Fall 1999. The STAR experiment's investigation of techniques and signals using hard probes to study the high energy-density matter at RHIC and to search for quark-gluon plasma formation will be described.

New short-pulse laser technology has made possible the production of extremely bright laser sources. The use of these new techniques on large scale Nd:Glass based laser systems would make it possible to produce 1000 TW (Petawatt) pulses. Such pulses would yield focused intensities exceeding 10{sup 21}W/cm{sup 2} corresponding to an electric field in excess of 100 e/a{sub 0}{sup 2} and an energy density equivalent to that of a 10 keV blackbody. Such a source would have important applications in x-ray laser research and lead to a fundamentally new class of experiments in atomic, nuclear, solid state, plasma and high-energy density physics. Such a facility could be constructed with existing chirped-pulse'' technology. A one-year period of research addressing outstanding technical questions can extend the technology resulting in a more compact and cost effective design. For this reason, we are seeking a Director's Initiative grant in the amount of $590,000 for FY89 to investigate these issues. An equivalent amount in personnel and facilities would be provided by Y-Division. The study will include development of a chirped-pulse'' front-end capable of producing laser pulses of 2 J at 1.053 {mu}m with a 1 psec pulsewidth laser. Upon completion, this front-end will be installed on …

The Westinghouse Savannah River Technology Center was requested by it`s sister site, West Valley Nuclear Service (WVNS), to develop a remote inspection system to gather wall thickness readings of their High Level Waste Tanks. WVNS management chose to take a proactive approach to gain current information on two tanks t hat had been in service since the early 70`s. The tanks contain high level waste, are buried underground, and have only two access ports to an annular space between the tank and the secondary concrete vault. A specialized remote system was proposed to provide both a visual surveillance and ultrasonic thickness measurements of the tank walls. A magnetic wheeled crawler was the basis for the remote delivery system integrated with an off-the-shelf Ultrasonic Data Acquisition System. A development program was initiated for Savannah River Technology Center (SRTC) to design, fabricate, and test a remote system based on the Crawler. The system was completed and involved three crawlers to perform the needed tasks, an Ultrasonic Crawler, a Camera Crawler, and a Surface Prep Crawler. The crawlers were computer controlled so that their operation could be done remotely and their position on the wall could be tracked. The Ultrasonic Crawler controls were …

Future applications of simulators in process control will see activities with high return on investment in areas such as concurrent engineering, hardware-in-the-loop controller testing, process fault detection, and Internet-retrievable simulation models and tools. These applications are based on advancing technology in the field of simulation technology. In this paper, the advancing technology will be reviewed, and projections to future uses of simulators in process control will be made.

Increasing the content limits of radioactive material packagings can save money and increase transportation safety by decreasing the total number of shipments required to transport large quantities of material. The contents of drum packages can be limited by unacceptable containment vessel pressures and temperatures due to the thermal properties of the insulation. The purpose of this work is to understand and predict the effects of insulation properties on containment system performance.

Differences are investigated in pion source sizes derived using {pi}{sup +}{pi}{sup +} and {pi}{sup -}{pi}{sup -} pairs in the large statistics data set collected with the E866 Forward Spectrometer for central Au+Au collisions at 11.6 A. {center_dot} GeV/c in AGS Experiment E866. These differences in source radii are interpreted using a simple classical description for the Coulomb and the transverse-momentum (p{sub T}) dependent source radius parameters. An estimated effective net charge responsible for the distortion is considerably smaller than the expected total projectile participant protons, which suggests that the system undergoes a rapid expansion in the longitudinal direction before freezeout. This picture is consistent with the results derived from the {pi}{sup -}/{pi}{sup +} singles yield ratios for the same reactions.

The deposition of compositionally modulated (Bi{sub 1-x}Sb{sub x}){sub 2}(Te{sub 1-y}Se{sub y}){sub 3} thermoelectric multilayer films by magnetron sputtering has been demonstrated. Structures with a period of 140{Angstrom} are shown to be stable to interdiffusion at the high deposition temperatures necessary for growth of single layer crystalline films with ZT {gt} 0.5. These multilayers are of the correct dimension to exhibit the electronic properties of quantum well structures. Furthermore it is shown that the Seebeck coefficient of the films is not degraded by the presence of this multilayer structure. It may be possible to synthesize a multilayer thermoelectric material with enhanced ZT by maximizing the barrier height through optimization of the composition of the barrier.

The STAR experiment at RHIC is a large acceptance detector. The electromagnetic calorimeter (EMC) will provide a sensitive trigger to study high p{sub t} jets and hard photons in AuAu, pp, and pAu collisions. The capability for the EMC to trigger on jets and direct photons was studied for trigger level 0. Trigger efficiencies and expected process rates were obtained for pp reactions. Results from pp interactions will be essential to the interpretation of AuAu results as well as for the spin physics program. These studies were performed with the standard STAR software chain which includes GEANT and EMC simulations. The HIJING event generator was used to provide input for the simulations.

When the Relativistic Heavy Ion Collider (RHIC) at BNL begins operation in the Fall of 1999, heavy ions will be accelerated in collider mode for the first time, and a new energy regime will be entered for Heavy Ion Physics. The Solenoidal Tracker At RHIC (STAR) detector has a near 4{pi} coverage and is dedicated to taking hadronic measurements. A large volume Time Projection Chamber placed in a solenoidal magnet at 0.5T is used to track and identify the many thousands of produced particles. STAR will measure many observables simultaneously on an event-by-event basis to study signatures of a possible QGP phase transition and the space-time evolution of the collision process. The goal is to obtain a fundamental understanding of the microscopic structure of hadronic interactions, at the level of quarks and gluons, at high energy densities. This paper outlines the physics STAR intends to study during the first year of operation.

Currently, there is interest in utilizing lignin, a major constituent of biomass, as a renewable source of chemicals and fuels. High yields of liquid products can be obtained from the flash or fast pyrolysis of biomass, but the reaction pathways that lead to product formation are not understood. To provide insight into the primary reaction pathways under process relevant conditions, we are investigating the flash vacuum pyrolysis (FVP) of lignin model compounds at 500 C. This presentation will focus on the FVP of {beta}-ether linkages containing aromatic methoxy groups and the reaction pathways of methoxy-substituted phenoxy radicals.