The Defense Threat Reduction Agency, DTRA, is a federal agency charged with safeguarding the nation from weapons of mass destruction, in particular nuclear weapons such as crude devices, and radiological dispersal devices (RDD), also known as dirty bombs. Both of which could be delivered using unconventional means such as by transporting them by a car or boat. Two years ago DTRA partnered with NNSA to evaluate commercially available technologies that could be deployed quickly to defend against threats posed by unconventional nuclear weapons under a program called the Unconventional Nuclear Warfare Defense (UNWD) Program. Lawrence Livermore National Laboratory (LLNL) was one of several National laboratories that participated in this program, which consisted in developing, deploying, and demonstrating detection systems suitable for military base protection. Two key contributions to this program by the LLNL team were the development of two Radiation Detection Buoys (RDB) deployed at Naval Base in Kings Bay in Georgia, and the Detection and Tracking System (DTS) demonstrated at Fort Leonard Wood Missouri, headquarters for the Total Force's Maneuver Support Center (MANSCEN). The RDB's were designed to detect the potential transportation of an unconventional nuclear or radiological weapon by a boat. The RDB's consisted of two commercial marine …

Our ability to simulate physical processes numerically is constrained by our ability to solve the resulting linear systems, prompting substantial research into the development of multiscale iterative methods capable of solving these linear systems with an optimal amount of effort. Overcoming the limitations of geometric multigrid methods to simple geometries and differential equations, algebraic multigrid methods construct the multigrid hierarchy based only on the given matrix. While this allows for efficient black-box solution of the linear systems associated with discretizations of many elliptic differential equations, it also results in a lack of robustness due to assumptions made on the near-null spaces of these matrices. This paper introduces an extension to algebraic multigrid methods that removes the need to make such assumptions by utilizing an adaptive process. The principles which guide the adaptivity are highlighted, as well as their application to algebraic multigrid solution of certain symmetric positive-definite linear systems.

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To achieve high focal spot intensities in heavy ion fusion, the ion beam must be compressed longitudinally by factors of ten to one hundred before it is focused onto the target. The longitudinal compression is achieved by imposing an initial velocity profile tilt on the drifting beam. In this paper, the problem of longitudinal drift compression of intense charged particle beams is solved analytically for the two important cases corresponding to a cold beam, and a pressure-dominated beam, using a one-dimensional warm-fluid model describing the longitudinal beam dynamics.

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We examine various options for calibration of NIF neutron detectors in the energy region E<14 MeV. These options include: downscatter of D-T fusion neutrons using plastic targets; nuclear reactions at a Tandem Van de Graaf accelerator; and ''white'' neutrons from a pulsed spallation source. As an example of the spallation option, we present some calibration data that was recently obtained with a single crystal CVD diamond detector at the Weapons Neutron Research facility (WNR) at LANL.

We present first principles, computational predictions of a porous, nano-structured semiconductor material that will reversibly store hydrogen for fuel cell applications. The material is competitive with current metal hydride storage materials, but contains only carbon and silicon, reducing both its cost and environmental impact. Additionally, unlike metal hydrides, the core skeleton structure of this material is unaltered when cycling from full hydrogen storage to full hydrogen depletion, removing engineering complications associated with expansion/contraction of the material.

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We examine the effect of the collective force due to coherent synchrotron radiation (CSR) in an electron storage ring with small bending radius. In a computation based on time-domain integration of the nonlinear Vlasov equation, we find the threshold current for a longitudinal microwave instability induced by CSR alone. The model accounts for suppression of radiation at long wave lengths due to shielding by the vacuum chamber. In a calculation just above threshold, small ripples in the charge distribution build up over a fraction of a synchrotron period, but then die out to yield a relatively smooth but altered distribution with eventual oscillations in bunch length. The instability evolves from small noise on an initial smooth bunch of r.m.s.length much greater than the shielding cutoff. The paper includes a derivation and extensive analysis of the complete impedance function Z for synchrotron radiation with parallel plate shielding. We find corrections to the lowest approximation to the coherent force which involve ''off-diagonal'' values of Z, that is, fields with phase velocity not equal to the particle velocity.

Medium carbon steel (MCS) is the candidate material for rock bolts to reinforce the borehole liners and emplacement drifts of the proposed Yucca Mountain (YM) high-level nuclear waste repository. Corrosion performance of this structural steel -AISI 1040- was investigated by techniques such as linear polarization, electrochemical impedance spectroscopy (EIS), and laboratory immersion tests in lab simulated concentrated YM ground waters. Corrosion rates of the steel were determined for the temperatures in the range from 25 C to 85 C, for the ionic concentrations of 1 time (1x), 10 times (10x), and hundred times (100x) ground waters. The MCS corroded uniformly at the penetration rates of 35-200 {micro}m/year in the de-aerated YM waters, and 200-1000 {micro}m/year in the aerated waters. Increasing temperatures in the de-aerated waters increased the corrosion rates of the steel. However, increasing ionic concentrations influenced the corrosion rates only slightly. In the aerated 1x and 10x waters, increasing temperatures increased the rates of MCS significantly. Inhibitive precipitates, which formed in the aerated 100x waters at higher temperatures (65 C and up) decreased the corrosion rates to the values that obtained for the de-aerated YM aqueous environments. The steel suffered pitting corrosion in the both de-aerated and aerated hot …

Weekly newspaper from Dallas, Texas that includes local, state, and national news and advertising of interest to the Lesbian, Gay, Bisexual, and Transgender (LGBT) community.

Calculational assessment and experimental verification of certain neutron cross sections that are related to widely needed new medical isotopes. Experiments were performed at the Oregon State University TRIGA Reactor and the High Flux Irradiation Reactor at Oak Ridge National Laboratory.

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We have measured the production of hv {approx} 4.7 keV x-rays from low-density Ti-doped aerogel ({rho} {approx} 3 mg/cc) targets at the OMEGA laser facility (University of Rochester), with the goal of maximizing x-ray output. Forty OMEGA beams ({lambda}{sub L} = 0.351 {micro}m) illuminated the two cylindrical faces of the target with a total power that ranged from 7 to 14 TW. The laser fully ionizes the target (n{sub e}/n{sub crit} {le} 0.1), and a laser-bleaching wave excites, supersonically, the high-Z emitter ions in the sample. Heating in the target was imaged with gated x-ray framing cameras and an x-ray streak camera. Ti K-shell x-ray emission was spectrally resolved with a two-channel crystal spectrometer and also with a set of filtered aluminum x-ray diodes, both instruments provide absolute measurement of the multi-keV x-ray emission. We find between 40 - 260 J of output with 4.67 {le} hv {le} 5.0 keV. Radiation-hydrodynamic calculations predict late time enhancement of the x-ray power due first to axial stagnation of the heating waves, then, ablatively-driven radial compression from the target walls.

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Funeral program for Mrs. Minerva Louise James Watson, born January 1, 1921 and died April 3, 2004. The funeral was held April 9, 2004 at Mt. Zion First Baptist Church, officiated by Rev. Kenneth A. Allen, Sr. Funeral arrangements were made through Carter-Taylor-Williams Mortuary, and she was buried in Southern Memorial Park in San Antonio, Texas.

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Understanding the transition-crossing process is crucial for improving Booster performance at high intensity. The synchronous phase appears to drop toward 90{sup o} right after transition regardless of beam intensity, more so at higher beam intensity. The implication is that the effective rf voltage (RFSUM) will run into a limit right after transition when the synchronous phase reaches 90{sup o} for high intensity beam. A reduction in RFSUM is also observed at the same time. Solutions, such as raising the rf voltage during the transition period or controlling the RFSUM reduction by increasing longitudinal emittance before transition, are potentially important for high intensity operation.