Cratering is a subject that has been studied by many investigators for many years for many purposes. These purposes range from experimental studies of physical properties to large scale excavations using explosive charges of kiloton size. In the past ten years considerable effort has been devoted to cratering experiments for the purposes of determining the effects of cratering by nuclear explosions, with recent accent on Plowshare applications. From the large amount of data available for craters in alluvian has been possible to establish very reliable relationships between charge size, depth of bursty crater radii, and crater depths. In addition it has been possible to construct a preliminary theory of the mechanics of explosive crater formation. The available experimental data for nuclear and high explosive craters are reviewed, with particular emphasis on the data for desert alluvium, and the pertinent relationships are derived. A theory of the important cratering mechanisms, which has been evolved on the basis of these data and data from other sources, is outlined. (auth)

As the first part of a study to evaluate the economics of the various steps leading to and including the permanent disposal of high-activity liquid and solid radioactive waste, costs of interim liquid storage of acid and alkaline Purex and Thorex wastes were estimated for storage times of 0.5 to 30 years. A 6- ton/day plant was assumed, processing 1500 tons/year of uranium converter fuel at a burnup of 10,000 Mwd/ton and 270 tons/year of thorium converter fuel at a burnup of 20,000 Mwd/ton. Tanks of Savannah River design were assumed, with stainless steel construction for acid wastes and mild steel construction for neutralized wastes. The operating cycle of each tank was assumed to consist of equal filling and emptying periods plus a full (or dead) period. With interim storage time defined as filling time plus full time, tank costs were minimum when full time was 40 to 70% of the interim storage time, using present worth considerations. For waste storage times of 0.5 to 30 years, costs ranged from 2.2 x 10/sup -3/ to 9.5 x 10/sup -3/ mill/kwh/sub e/ for acid wastes and from 1.7 x 10/sup -3/ to 5.1 x 10/sup -3/ mill/kwh/sub e/ for neutralized wastes. …

At the stage of the antiproton-nucleon annihilation chain of events relevant to propulsion the annihilation produces energetic charged pions and gamma rays. If annihilation occurs in a complex nucleus, protons, neutrons, and other nuclear fragments are also produced. The charge, number, and energy of the annihilation products are such that annihilation rocket engine concepts involving relatively low specific impulse (I/sub sp/ approx. = 1000 to 2000 s) and very high I/sub sp/ (3 x 10/sup 7/ s) appear feasible and have efficiencies on the order of 50% for annihilation energy to propulsion energy conversion. At I/sub sp/'s of around 15,000 s, however, it may be that only the kinetic energy of the charged nuclear fragments can be utilized for propulsion in engines of ordinary size. An estimate of this kinetic energy was made from known pieces of experimental and theoretical information. Its value is about 10% of the annihilation energy. Control over the mean penetration depth of protons into matter prior to annihilation is necessary so that annihilation occurs in the proper region within the engine. Control is possible by varying the antiproton kinetic energy to obtain a suitable annihilation cross section. The annihilation cross section at low energies is …

Currently, direct fuel rho r measurements on Inertial Confinement Fusion (ICF) targets by neutron activation of the argon tracer gas mixed with the DT fuel would require a 100 fold increase in neutron yield. Bromine, on the other hand, has excellent properties for neutron activation analysis at neutron yields of 10two' to 10/sup 8/, when present at an internal pressure of from 0.1 to 0.2 atmospheres. Bromine addition is accomplished in a 2 furnace system using the dried-gel method of microsphere production. An upper furnace operated at 1500/sup 0/C is separated from a lower furnace by a cooled zone. The lower furnace is filled with bromine gas and operated at approximately 1250/sup 0/C. The upper furnace is the glass production furnace. The cooled zone in between the upper and lower furnace is to prevent the hot bromine gas from rising into the upper furnace. The microspheres pass through the cooled zone and immediately into the 1250/sup 0/C bromine furnace where the bromine permeates into the spheres.

The Schroedinger Integral Equation is derived for an N-body system, and solutions for required Green's functions are obtained. The initial method of numerical solution has yielded the correct ground states and lower excited states of He (test case) and dt..mu... Steps are being taken to improve the numerical accuracy.

A theory of exploding pusher laser pusher targets is compared to results of LASNEX calculations and to Livermore experiments. A scaling relationship is described which predicts the optimum target/pulse combinations as a function of the laser power.

For antiproton energies of several eV or less, annihilation in matter occurs through atomic rearrangement processes in which the antiproton becomes bound to a nucleus prior to annihilation. Existing calculations of the antiproton-hydrogen atom rearrangement cross section are semiclassical and employ the Born-Oppenheimer approximation. They also employ various arguments in regard to the behavior of the system when the Born-Oppenheimer approximation breaks down at small antiproton-proton separations. These arguments indicate that rearrangement is essentially irreversible. In the present study, a detailed investigation was made of the antiproton-hydrogen atom system when the Born-Oppenheimer approximation breaks down. The results of this study indicate that the previous arguments were approximately correct, but that there is a significant probability for rearrangement reversing prior to annihilation. This probability is estimated to be about 20%. 8 refs., 4 figs., 2 tabs.

In this paper, we present a broad comparison of studies for a selected set of parameters for different nuclear reactor types including the next generation. This serves as an overview of key parameters which provide a semi-quantitative decision basis for selecting nuclear strategies. Out of a number of advanced reactor designs of the LWR type, gas cooled type, and FBR type, currently on the drawing board, the Advanced Light Water Reactors (ALWR) seem to have some edge over other types of the next generation of reactors for the near-term application. This is based on a number of attributes related to the benefit of the vast operating experience with LWRs coupled with an estimated low risk profile, economics of scale, degree of utilization of passive systems, simplification in the plant design and layout, modular fabrication and manufacturing. 32 refs., 1 fig., 3 tabs.

In this paper, we solve different theoretical problems associated with the calculation of the kernel occurring in the Hill-Wheeler integral equations within the framework of generator coordinate method. In particular, we extend the Wick's theorem to nonorthogonal Bogoliubov states. Expressions for the overlap between Bogoliubov states and for the generalized density matrix are also derived. These expressions are valid even when using an incomplete basis, as in the case of actual calculations. Finally, the Hill-Wheeler formalism is developed for a finite range interaction and the Skyrme force, and evaluated for the latter. 20 refs., 1 fig., 4 tabs.

As a result of the accident on March 28, 1979, fuel debris was dispersed into the primary coolant system of the Three Mile Island Unit 2 (TMI-2) reactor. Location and quantification of fuel debris is essential for TMI-2 recovery. TMI-2 fuel debris assessments can be carried out nondestructively by neutron and gamma-ray dosimetry. Efforts to date have been directed toward fuel debris characterization of the makeup and purification demineralizers, will maintain reactor coolant water purity. Two highly specialized dosimetry methods were applied: solid state track recorder (SSTR) neutron dosimetry and continuous gamma-ray spectrometry. The most recent dosimetry results are reviewed and compared. To reduce the intense background radiation from /sup 137/Cs, the Si(Li) detector was surrounded by a 5.5 diameter lead shield 8'' shield in length. The spectral data were used to determine the intensity of the 2.18 MeV gamma ray from the fission product /sup 144/Ce. Assuming this fission product does not migrate out of the fuel, the quantity of /sup 144/Ce is directly related to the quantity of fuel present. Based on the observed source geometry and the measured flux of the /sup 144/Ce 2.18 MeV gamma rays, the fuel content of the A demineralizer was calculated to …

This paper reports the results of calculations of electron impact ionization cross sections for a variety of heavy ions using a distorted wave Born-exchange approximation. The target is described by a Hartree-Fock wavefunction. The scattering matrix element is represented by a triple partial wave expansion over incident, scattered, and ejected (originally bound) continuum states. These partial waves are computed in the potentials associated with the initial target (incident and scattered waves) and the residual ion (ejected waves). A Gauss integration was performed over the distribution of energy between the two final state continuum electrons. For ionization of closed d- and f-subshells, the ejected f-waves were computed in frozen-core term-dependent Hartree-Fock potentials, which include the strong repulsive contribution in singlet terms which arises from the interaction of an excited orbital with an almost closed shell. Ground state correlation was included in some calculations of ionization of d/sup 10/ subshells.

Round wire Bi 2212 is emerging as a viable successor ofNb3Sn in High Energy Physics and Nuclear Magnetic Resonance, to generatemagnetic fields that surpass the intrinsic limitations of Nb3Sn. Ratherbold claims are made on achievable magnetic fields in applications usingBi 2212, due to the materials' estimated critical magnetic field of 100 Tor higher. High transport currents in high magnetic fields, however, leadto large stress on, and resulting large strain in the superconductor. Theeffect of strain on the critical properties of Bi-2212 is far fromunderstood, and strain is, as with Nb3Sn, often treated as a secondaryparameter in the design of superconducting magnets. Reversibility of thestrain induced change of the critical surface of Nb3Sn, points to anelectronic origin of the observed strain dependence. Record breaking highfield magnets are enabled by virtue of such reversible behavior. Straineffects on the critical surface of Bi-2212, in contrast, are mainlyirreversible and suggest a non-electronic origin of the observed straindependence, which appears to be dominated by the formation of cracks inthe superconductor volumes. A review is presented of available results onthe effects of strain on the critical surface of Bi-2212, Bi-2223 andYBCO. It is shown how a generic behavior emerges for the (axial) straindependence of the critical …

This summer I had the privilege of working at Lawrence Livermore National Laboratory under the Nonproliferation, Homeland and International Security Directorate in the Chemical and Biological Countermeasures Division. I worked exclusively on the Viral Identification and Characterization Initiative (VICI) project focusing on the development of multiplexed polymerase chain reaction (PCR) assays. The goal of VICI is to combine several disciplines such as molecular biology, microfluidics, and bioinformatics in order to detect viruses and identify them in order to effectively and quickly counter infectious disease, natural or engineered. The difficulty in such a countermeasure is that little is known about viral diversity due to the ever changing nature of these organisms. In response, VICI is developing a new microfluidic bioanalytical platform to detect known and unknown viruses by analyzing every virus in a sample by isolating them into picoliter sized droplets on a microchip and individually analyzing them. The sample will be injected into a channel of oil to form droplets that will contain viral nucleic acids that will be amplified using PCR. The multiplexed PCR assay will produce a series of amplicons for a particular virus genome that provides an identifying signature. A device will then detect whether or not …

Many different materials are used in the National Ignition Facility, NIF, located at Lawrence Livermore National Laboratory, LLNL. Some of these are exposed to significant doses of ionizing radiation. Two elastomers are of special interest because they are used in sealing applications with long expected lifetimes. These are LPU4, a polyurethane formulated at LLNL, and Dow Corning DC93-500, a silicone RTV elastomer. In 2004 a program to determine the impact of ionizing radiation on the stress relaxation and compression set characteristics of these two elastomers was undertaken. Since the materials are used in continuous compression and must reliably seal, the primary test utilized was a stress relaxation test. This test provides insight into the ability of a seal to remain functional in a static seal. The test determines how much residual force remains after a certain period of time under compression. The temperature and absorbed radiation dose can dramatically impact this property. In this study the only independent environmental variable studied is the effect of radiation at ambient temperatures. Two levels of radiation exposure were studied, 1 MRad, and 10 MRad. One of the independent test parameters is the compression deflection during storage and in this test the value used …

The authors have measured the relaxation time of hot electrons in short pulse laser-solid interactions using a picosecond time-resolved x-ray spectrometer and a time-integrated electron spectrometer. Employing laser intensities of 10{sup 17}, 10{sup 18}, and 10{sup 19} W/cm{sup 2}, they find increased laser coupling to hot electrons as the laser intensity becomes relativistic and thermalization of hot electrons at timescales on the order of 10 ps at all laser intensities. They propose a simple model based on collisional coupling and plasma expansion to describe the rapid relaxation of hot electrons. The agreement between the resulting K{sub {alpha}} time-history from this model with the experiments is best at highest laser intensity and less satisfactory at the two lower laser intensities.

Pressed-powdered crystallites of intrinsically anisotropic materials have been shown to undergo irreversible volume expansion when subjected to repeated cycles of heating and cooling. We develop a coarse-grained (micron-scale) interaction Hamiltonian for this system and perform molecular dynamics simulations, which quantitatively reproduce the experimentally observed irreversible growth. The functional form and values of the interaction parameters at the coarse-grained level are motivated by our knowledge at the atomic/molecular scale, and allows a simple way to incorporate the effect of polymeric binder. We demonstrate that irreversible growth happens only in the presence of intrinsic crystalline anisotropy of the powder material, is mediated by particles much smaller than the average crystallite size, and can be significantly reduced in the presence of high-strength polymeric binder with elevated glass transition temperatures.

Results from Super-K, SNO, and KamLAND provide strong evidence that neutrinos undergo flavor-changing oscillations and therefore have non-zero mass. The {nu}-disappearance observations by KamLAND, assuming CPT conservation, point to matter enhanced (MSW) oscillations with large mixing angles as the solution to the solar neutrino problem--a result consistent with the MSW parameters recently defined by these experiments. This requires that the observed neutrino flavors (e, {mu}, and tau) are not mass eigenstates, but are linear combinations of the mass eigenstates of the neutrino. However, such oscillation experiments can only determine the differences in the masses of the neutrinos, not the absolute scale of neutrino mass. What can be inferred from these experiments is that at least one species of neutrino has a mass greater than 55 meV. In fact, the WMAP observations of large-scale structure point to a sum-neutrino mass of {approx} 0.7 eV (roughly 0.25 eV/species assuming democracy between the flavors). Furthermore, there is still the important issue of whether the neutrino and anti-neutrino are distinct particles (i.e. Dirac type) or not (Majorana type). The only way to answer both of these questions is through neutrinoless double beta decay (DBD) experiments. CUORE (Cryogenic Underground Observatory for Rare Events) is a …

This procedure provides instructions forassembling the following CH packaging payload: Drum payload assembly Standard Waste Box (SWB) assembly Ten-Drum Overpack (TDOP)

Corrosion rates using supernatant samples retrieved from near the top of the liquid layer were determined for the tanks. Corrosion rates using settled solids (saltcake) were determined. The supernatant samples were tested as received without argon sparging. The settled solid sample segments were extruded under anaerobic condition and kept under a sweep of humidified argon gas during 'the electrochemical corrosion testing. The class of steel used to construct the tank in question was used, and test coupons were allowed to equilibrate for a minimum of 18 hours before a Tafel scan was initiated. The coupons were scanned from -250 mV to +250 mV from the rest or open circuit potential. The corrosion rate is reported along with the corrosion current measurement, open circuit potential, and a chi-square statistic generated by the instrument controlling and analysis algorithm.

In the near future, the United States will be facing constraints on energy availability due to the heightened demand for both energy and water, especially during droughts and summers. Increasing stress on the inextricably linked resource availability of both water and energy can be mitigated with integrated planning. Exchanging data is an important component to current and future mitigation approaches within the Energy-Water Nexus. We describe the types of relationships that are formed in the United States EWN, and address the data sharing obstacles within. Approaches to removing the obstacles of data sharing are presented, based on case studies.

One of the central challenges in modern science is the need to quickly derive knowledge and understanding from large, complex collections of data. We present a new approach that deals with this challenge by combining and extending techniques from high performance visual data analysis and scientific data management. This approach is demonstrated within the context of gaining insight from complex, time-varying datasets produced by a laser wakefield accelerator simulation. Our approach leverages histogram-based parallel coordinates for both visual information display as well as a vehicle for guiding a data mining operation. Data extraction and subsetting are implemented with state-of-the-art index/query technology. This approach, while applied here to accelerator science, is generally applicable to a broad set of science applications, and is implemented in a production-quality visual data analysis infrastructure. We conduct a detailed performance analysis and demonstrate good scalability on a distributed memory Cray XT4 system.

This lecture describes the physics considerations entering the magnet design of a quadrupole-stabilized, tandem-mirror system.

A DYNA3D model of the DT-20 shipping container was constructed. Impact onto a rigid steel surface at a velocity of 44 ft/sec (30 foot gravity drop) was studied. The orientation of most interest was a side-drop, but end and corner drops were also studied briefly. The assembly for the baseline side impact contained a 150 lb. payload. During this drop, the outer drum sustains plastic strains of up to 0.15, with most the deformation near the rim. The plywood/Celotex packing is crushed about 3 inches. The inner sealed can sees significant stresses, but barely reaches the onset of yielding in some local areas. Based on hand calculations, the bolts joining the can halves could see stresses near 50 ksi. It is felt that overall, the container should survive this drop. However, detailed modeling of the rim closure and the center bolted joint was not possible due to time constraints. Furthermore, better material models and properties are needed for the Celotex, plywood, and honeycomb in particular. 39 figs., 1 tab.

RINGBEARER is a particle simulation code for modelling an electron beam propagating in a gas characterized by a space and time varying conductivity generated by the beam. The code has two spatial dimensions, the beam is assumed to be axially symmetric. Equations for the beam driven pinch field, the plasma density, and the conductivity are given along with the appropriate initial conditions and boundary conditions. The equations governing particle energy loss, transverse motion, and scattering, in the beam generated pinch field are presented. The analytic models used in the code are presented with either references or derivations.