The Department of Energy (DOE) has given the Spallation Neutron Source (SNS) project approval to begin Title I design of the proposed facility to be built at Oak Ridge National Laboratory (ORNL) and construction is scheduled to commence in FY01 . The SNS initially will consist of an accelerator system capable of delivering an {approximately}0.5 microsecond pulse of 1 GeV protons, at a 60 Hz frequency, with 1 MW of beam power, into a single target station. The SNS will eventually be upgraded to a 2 MW facility with two target stations (a 60 Hz station and a 10 Hz station). The radiation transport analysis, which includes the neutronic, shielding, activation, and safety analyses, is critical to the design of an intense high-energy accelerator facility like the proposed SNS, and the Monte Carlo method is the cornerstone of the radiation transport analyses.

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A new frontier in physics originated with programs at two Brookhaven National Laboratory facilities--the Cosmotron and the Alternating Gradient Synchrotron. The development of this frontier over a half century is described, as it turned from conventional nuclear physics to the hypernuclei and the study of strange matter.

Criticality safety analyses often require detailed modeling of complex geometries. Effective visualization tools can enhance checking the accuracy of these models. This report describes the KENO3D visualization tool developed at the Oak Ridge National Laboratory (ORNL) to provide interactive visualization of KENO V.a and KENO-VI criticality safety models. The development of KENO3D is part of the current efforts to enhance the SCALE (Standardized Computer Analyses for Licensing Evaluations) computer software system.

OAK-B135 University of Washington Lab Report to SNEAP, 1999. The NPL tandem Van de Graaff accelerator chains ran 1869 hours between 9/1/98 and 8/31/99. The DEIS ran 356 hours and the SpIS ran 667. There were 28 experiment-days in which the LINAC and tandem were used together and seven days when the tandem was used, with one of the external ion sources, as a tandem. Four of these were with light ions and three with heavy ions. There were 68 days of Tandem Terminal Ion Source (TIS) development or repair, and 46 days of TIS installation or removal or changing TIS ion species. The TIS/tandem was used a total of 70 days to deliver p, d, {sup 3}He, or {sup 4}He beams for use by an experimenter. There were 47 experiment-days during which the injector deck was used to generate C{sub 60} or LiF{sub 3} clusters, which were then investigated without further acceleration. They had 25 tank openings over the year. There were three scheduled openings for the installation or removal of the TIS, and seven to change the TIS ion species. There were 10 openings for {sup 4}He ion source and column resistor gradient development. There were four openings …

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E885, an experiment performed at the Brookhaven National Laboratory Alternate Gradient Synchrotron (BNL AGS) achieved high sensitivity in a search for {Lambda}{Lambda} hypernuclei, {Xi} hypernuclei, and the H particle. Evidence was found for {Xi} hypernuclei. Possible extensions of the methods used are discussed.

Design parameters for the target region of the Spallation Neutron Source were calculated by following histories of 1 GeV protons and their shower of particles with the Monte Carlo code MCNPX. In particular, neutron currents, radiation damages, doses and heat distributions for the target region of the facility along the path of the proton beam are presented from the point of view of the perturbation effects of the proton beam window.

The authors have developed a research prototype device for low level detection of SEB, ricin, botulinum toxin and ovalbumin in liquid samples. This hand-held, low power device analyzes samples by capillary zone electrophoresis (CZE) and capillary gel electrophoresis (CGE) in a parallel microchannel format, and provides sensitive detection of fluorescently-tagged analytes using miniature 392 nm diode laser-induced fluorescence. They have successfully demonstrated simultaneous parallel channel separations, fully automated high voltage control of fluidics and automated data analysis with toxin identification and semi-quantitation in the presence of aerosol backgrounds in a stand-alone self-contained unit. Tests of the fully integrated device indicate high sensitivity detection (as low as 5 nM) and cycle times of 5-10 minutes.

The design of reactivity monitoring systems for accelerator-driven systems must be investigated to ensure that such systems remain subcritical during operation. The Monte Carlo codes LAHET and MCNP-DSP were combined together to facilitate the design of reactivity monitoring systems. The coupling of LAHET and MCNP-DSP provides a tool that can be used to simulate a variety of subcritical measurements such as the pulsed neutron, Rossi-{alpha}, or noise analysis measurements.

We present a simple method to deal with caustics in the semiclassical approximation to the partition function of a one-dimensional quantum system. The procedure, which makes use of complex trajectories, is applied to the quartic double-well potential.

It is empirically observed that the non-leptonic decay of strange hadrons is enhanced when the change in isospin is 1/2. This is generalized in the ''{Delta}I = 1/2 rule'' that states that all such decays proceed predominantly through {Delta}I = 1/2 amplitudes. However, there is no definitive explanation for this apparently universal rule. Non-mesonic decay of {Lambda}-hypernuclei can occur through a weak decay process {Lambda}N {r_arrow} {eta}N. When stimulated by a neutron, two neutrons are emitted from the nucleus, and when stimulated by a proton, a proton and neutron are emitted. By measuring the relative decay widths ({Gamma}{sub n}/{Gamma}{sub p}) in the full set of s-shell hypernuclei, a sensitive test of the {Delta}I = 1/2 rule, and the determination of its applicability to non-mesonic decays can be made. In addition, information about the spin-isospin dependence of the weak decay process can be extracted. A measurement of {Gamma}{sub n}/{Gamma}{sub p}, to an accuracy of even 50% will be sufficient to address important issues relating to the {Delta}I = 1/2 rule and to the weak decay process. The experiment will measure the ratio {Gamma}{sub n}/{Gamma}{sub p}, following the decay of {sup 4}H which is produced by a stopped K{sup {minus}} beam in …

OAK-B135 Tandem Terminal Ion Source. The terminal ion source (TIS) was used in several experiments during this reporting period, all for the {sup 7}Be({gamma}){sup 8}B experiment. Most of the runs used {sup 1}H{sup +} at terminal voltages from 0.3 MV to 1.5 MV. One of the runs used {sup 2}H{sup +} at terminal voltage of 1.4 MV. The other run used {sup 4}He{sup +} at a terminal voltage of 1.37 MV. The list of experiments run with the TIS to date is given in table 1 below. The tank was opened four times for unscheduled source repairs. On one occasion the tank was opened to replace the einzel lens power supply which had failed. The 10 kV unit was replaced with a 15 kV unit. The second time the tank was opened to repair the extractor supply which was damaged by a tank spark. On the next occasion the tank was opened to replace a source canal which had sputtered away. Finally, the tank was opened to replace the discharge bottle which had been coated with aluminum sputtered from the exit canal.