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USDOE LABORATORY VIEWS ON U.S.-RUSSIAN PARTNERSHIP FOR NUCLEAR SECURITY. (open access)

USDOE LABORATORY VIEWS ON U.S.-RUSSIAN PARTNERSHIP FOR NUCLEAR SECURITY.

This paper summarizes an analysis of the U.S.-Russian Nuclear Material Protection, Control and Accounting (MPC&A) Program, developed on the basis of extensive discussions with U.S. laboratory participants as well as personal experience. Results of the discussions have been organized into three main areas: Technical/MPC&A Progress; Programmatic and Administrative Issues; and Professional Aspects, Implications for MPC&A effectiveness, for MPC&A sustainability, and for future relations and collaboration are derived. Suggested next steps are given.
Date: July 26, 1998
Creator: KEMPF,C. R.
System: The UNT Digital Library
Overview of the Hanford risk management plan (open access)

Overview of the Hanford risk management plan

The Project Hanford Management Contract called for the enhancement of site-wide decision processes, and development of a Hanford Risk Management Plan to adopt or develop a risk management system for the Hanford Site. This Plan provides a consistent foundation for Site issues and addresses site-wide management of risks of all types. It supports the Department of Energy planning and sitewide decision making policy. Added to this requirement is a risk performance report to characterize the risk management accomplishments. This paper presents the development of risk management within the context of work planning and performance. Also discussed are four risk elements which add value to the context.
Date: March 26, 1998
Creator: Halverson, T. G.
System: The UNT Digital Library
Influence of the incident particle energy on the fission product mass distribution. (open access)

Influence of the incident particle energy on the fission product mass distribution.

For {sup 238}U targets and the five elements considered here, the best yields of neutron-rich isotopes are obtained from neutrons in the 2-20 MeV range. High energy beams of neutrons, protons, and deuterons have comparable integral yields per element to neutrons below 20 MeV, but the distributions are peaked at lower neutron numbers. This is presumably due to a higher neutron multiplicity in the pre-equilibrium stage and/or the compound nucleus/fission stage. For {sup 235}U targets there are high yields predicted especially for thermal neutrons, and also for the fast neutron spectrum. For the high energy neutrons, protons, and deuterons {sup 235}U has no advantage over {sup 238}U. A detailed comparison of the relative advantages of {sup 235}U and {sup 238}U for radioactive beam applications is beyond the scope of this study and will be addressed in the future. The present work is the first step of a more detailed analysis of various possible one- and two-step target geometry calculated with the LAHET code system. It is intended to serve as a guide in choosing geometry and beams for future studies. It is desirable to extend this study to higher beam energies, e.g. 200 to 1000 MeV, but at this time …
Date: August 26, 1998
Creator: Gomes, I. C.
System: The UNT Digital Library
Quasi-dynamic pressure and temperature (open access)

Quasi-dynamic pressure and temperature

The phase transformation of {beta}-HMX (< 0.5% RDX) to the {delta} phase has been studied for over twenty years and more recently with an optically sensitive second harmonic generation technique. Shock studies of the plastic binder composites of HMX have indicated that the transition is perhaps irreversible, a result that concurs with the static pressure results published by F. Goetz et al. [l] in 1978. However the stability field favors the {beta} polymorph over {delta} as pressure is increased (up to 5.4 GPa) along any sensible isotherm. In this experiment strict control of pressure and temperature is maintained while x-ray and optical diagnostics are applied to monitor the conformational dynamics of HMX. Unlike the temperature induced {beta} -> {delta} transition, the pressure induced is heterogeneous in nature. The room pressure and temperature {delta} -> {beta} transition is not immediate although it seems to occur over tens of hours. Transition points and kinetics are path dependent and so this paper describes our work in progress.
Date: August 26, 1998
Creator: Zaug, J. M.; Blosch, L. L.; Craig, I. M.; Hansen, D. W.; Aracne-Ruddle, C. M. & Shuh, D. K.
System: The UNT Digital Library
RHIC LONGITUDINAL PARAMETER REVISION. (open access)

RHIC LONGITUDINAL PARAMETER REVISION.

Recent experience showed that bunch rotations are needed in the AGS for gold as well as proton operations before the beams are injected into RHIC. The longitudinal bunch area is increased for gold operation from 0.3 up to 0.5 eV {center_dot}s/u at design intensity. This paper reviews the revised longitudinal parameters in RHIC during injection, acceleration, transition crossing, rebucketing, and storage for gold and proton beams, accommodating for the change in injection conditions at the AGS.
Date: June 26, 1998
Creator: WEI, J.
System: The UNT Digital Library
Bunched Beam Echos in the Ags. (open access)

Bunched Beam Echos in the Ags.

Beam echos have been measured at FNAL [3] and CERN [5] in coasting beams. A coherent oscillation introduced by a short RF burst decoheres quickly, but a coherent echo of this oscillation can be observed if the decohered oscillation is ''bounced off'' a second RF burst. In this report we describe first longitudinal echo measurements of bunched beam in the AGS accelerator. We applied a method proposed by Stupakov [1] for transverse beam echos, where the initial oscillation is produced by a dipole kick and is bounced off a quadrupole kick. In the longitudinal case the dipole and quadrupole kicks are produced by a cavities operating at a 90{degree} and 0{degree} phase shift, respectively.
Date: June 26, 1998
Creator: Kewisch, J.
System: The UNT Digital Library
Results From Betatron Phase Measurements in Rhic During the Sextant Test. (open access)

Results From Betatron Phase Measurements in Rhic During the Sextant Test.

The Sextant Test of the Relativistic Heavy Ion Collider (RHIC) was an important step towards its completion. One sixth of the two RHIC accelerators was fully commissioned. Gold ion beam was injected and transported through one sextant of one of the two rings. The betatron phase advance per cell was measured by recording differences in the horizontal and vertical positions of the beam at the end of the sextant due to a sequence of correction dipole kicks along the beam line. Measurement results show excellent agreement with predicted values, confirming that production measurements of the integral functions of the quadrupoles were very accurate, and that the polarity of all elements (correction dipoles, quadrupoles, dipoles etc.) was correct.
Date: June 26, 1998
Creator: Trbojevic, D.
System: The UNT Digital Library
The Design Process of Physical Security as Applied to a U.S. Border Point of Entry (open access)

The Design Process of Physical Security as Applied to a U.S. Border Point of Entry

This paper describes the design process of physical security as applied to a U.S. Border Port of Entry (PoE). Included in this paper are descriptions of the elements that compose U.S. border security. The physical security design will describe the various elements that make up the process as well as the considerations that must be taken into account when dealing with system integration of those elements. The distinctions between preventing unlawful entry and exit of illegal contraband will be emphasized.
Date: October 26, 1998
Creator: Wagner, G.G.
System: The UNT Digital Library
Modified phosphate ceramics for stabilization and solidification of salt mixed wastes. (open access)

Modified phosphate ceramics for stabilization and solidification of salt mixed wastes.

Novel chemically bonded phosphate ceramics have been investigated for stabilization and solidification of chloride and nitrate salt wastes. Using low-temperature processing, we stabilized and solidified chloride and nitrate surrogate salts (with hazardous metals) in magnesium potassium phosphate ceramics up to waste loadings of 70-80 wt.%. A variety of characterizations, including strength, microstructure, and leaching, were then conducted on the waste forms. Leaching tests show that all heavy metals in the leachant are well below the EPAs universal treatment standard limits. Long-term leaching tests, per ANS 16. 1 procedure, yields leachability index for nitrate ions > 12. Chloride ions are expected to have an even higher (i.e., better) leachability index. Structural performance of these final waste forms, as indicated by compression strength and durability in aqueous environments, satisfies the regulatory criteria. Thus, based on the results of this study, it seems that phosphate ceramics are viable option for containment of salt wastes.
Date: June 26, 1998
Creator: Singh, D.
System: The UNT Digital Library
Measurements of the Betatron Functions and Phases in Rhic. (open access)

Measurements of the Betatron Functions and Phases in Rhic.

The Relativistic Heavy Ion Collider (RHIC) consists of two rings with six fold symmetry. The six interaction regions (IR)s are connected with twelve FODO cells. RHIC quadrupoles in the interaction regions have independent tuning capability. The betatron functions will be measured by a three methods. First, tunable IR quadrupoles will be adjusted to measure betatron functions at those locations through the change in tune. Second, sinusoidal coherent dipole oscillations will be used to measure the betatron phases and functions (as performed in LEP). Third, a correction dipole kick technique will be used (as at Fermilab). Special attention will be given to the ''betatron squeeze'' procedure by which the two large experiments PHENIX and STAR will achieve minimum betatron functions between 1 and 2 m.
Date: June 26, 1998
Creator: Trbojevic, D.
System: The UNT Digital Library
EMITTANCE CONTROL OF A BEAM BY SHAPING THE TRANSVERSE CHARGE DISTRIBUTION, USING A TOMOGRAPHY DIAGNOSTIC. (open access)

EMITTANCE CONTROL OF A BEAM BY SHAPING THE TRANSVERSE CHARGE DISTRIBUTION, USING A TOMOGRAPHY DIAGNOSTIC.

A high-brightness beam is very important for many applications. A diagnostic that measures the multi-dimensional phase-space density-distribution of the electron bunch is a must for obtaining such beams. Measurement of a slice emittance has been achieved [1]. Tomographic reconstruction of phase space was suggested [2] and implemented [3,4] using a single quadrupole scan. In the present work we give special attention to the accuracy of the phase space reconstruction and present an analysis using a transport line with nine focusing magnets and techniques to control the optical functions and phases. This diagnostic, coupled with control of the radial charge distribution of presents an opportunity to improve the beam brightness. Combining the slice emittance and tomography diagnostics lead to an unprecedented visualization of phase space distributions in 5 dimensional phase-space and an opportunity to perform high-order emittance corrections.
Date: June 26, 1998
Creator: Yakimenko, V.
System: The UNT Digital Library
Computational studies of the reactions of CH3I with H and OH (open access)

Computational studies of the reactions of CH3I with H and OH

Article on computational studies of the reactions of CH3I with H and OH.
Date: March 26, 1998
Creator: Marshall, Paul; Misra, Ashutosh & Berry, Rajiv
System: The UNT Digital Library
The Holifield Radioactive Ion Beams Facility (HRIBF) -- getting ready to do experiments (open access)

The Holifield Radioactive Ion Beams Facility (HRIBF) -- getting ready to do experiments

The conversion of the HHIRF facility to a Radioactive Ion Beam facility started in 1994. In this ISOL type facility the Cyclotron has been re-fitted as a driver providing high intensity proton beams which react with the target from which the radioactive products are extracted and then accelerated in the Tandem Electrostatic Accelerator to the desired energy for nuclear science studies. Facilities for nuclear physics experiments are at different stages of development: A Recoil Mass Spectrometer (RMS) with a complement of detectors at the focal plane and around the target is used primarily for nuclear structure studies. A large recoil separator combining velocity and momentum selection, with its complement of focal plane detectors, will be dedicated to measurements relevant to nuclear astrophysics. The Enge Split Pole spectrograph is being re-fitted for operation in a gas filled mode, making it a more versatile tool for nuclear reaction studies. With the new experimental equipment being commissioned and the prospects of running experiments with low intensity radioactive beams a significant effort to develop equipment for beam diagnostics is underway. Some of the efforts and results in developing beam diagnostic tools will be described.
Date: February 26, 1998
Creator: Shapira, D. & Lewis, T. A.
System: The UNT Digital Library
Interface Characterization Techniques for 304L Stainless Steel Resistance Upset Welds (open access)

Interface Characterization Techniques for 304L Stainless Steel Resistance Upset Welds

In an effort to better characterize and classify austenitic stainless steel resistance upset welds, standard methods have been examined and alternative methods investigated. Optical microscopy yields subjective classification due to deformation obscured bond lines and individual perception. The use of specimen preparations that better reveal grain boundaries aids in substantiating optical information. Electron microscopy techniques produce quantitative information in relation to microstructural constituents. Orientation Imaging Microscopy (OIM) is a relatively new technique for obtaining objective, quantitative information pertaining to weld integrity, i.e., percent grain boundary growth across the interface.
Date: July 26, 1998
Creator: Abeln, Terri G.; Kackenko, E. Jim; Necker, Carl T. & Field, Robert D.
System: The UNT Digital Library
The dielectric boundary condition for the embedded curved boundary (ECB) method (open access)

The dielectric boundary condition for the embedded curved boundary (ECB) method

A new version of ECB has been completed that allows nonuniform grid spacing and a new dieledric boundary condition. ECB was developed to retain the simplicity and speed of an orthogonal mesh while capturing much of the fidelity of adaptive, unstructured finite element meshes. Codes based on orthogonal meshes are easy to work with and lead to well-posed elliptic and parabolic problems that are comparatively easy to solve. Generally, othogonal mesh representations lead to banded matrices while unstructured representations lead to more complicated sparse matrices. Recent advances in adapting banded linear systems to massively parallel computers reinforce our opinion that iterative field solutions utilizing banded matrix methods will continue to be competitive. Unfortunately, the underlying ``stair-step`` boundary representation in simple orthogonal mesh (and recent Adaptive Mesh Refinement) applications is inadequate. With ECB, the curved boundary is represented by piece-wise-linear representations of curved internal boundaries embedded into the orthogonal mesh- we build better, but not more, coefficients in the vicinity of these boundaries-and we use the surplus free energy on more ambitious physics models. ECB structures are constructed out of the superposition of analytically prescribed building blocks. In 2-D, we presently use a POLY4 (linear boundaries defined by 4 end points), …
Date: January 26, 1998
Creator: Hewwitt, D. W., LLNL
System: The UNT Digital Library
Multi-stage selection catalytic reduction of NO{sub x} in lean burn engine exhaust (open access)

Multi-stage selection catalytic reduction of NO{sub x} in lean burn engine exhaust

Recent studies suggest that the conversion of NO to NO{sub 2} is an important intermediate step in the selective catalytic reduction (SCR) of NO{sub x} to N{sub 2}. These studies have prompted the development of schemes that use an oxidation catalyst to convert NO to NO{sub 2}, followed by a reduction catalyst to convert NO{sub 2} to N{sub 2}. Multi-stage SCR offers high NO{sub x} reduction efficiency from catalysts that, separately, are not very active for reduction of NO, and alleviates the problem of selectivity between NO reduction and hydrocarbon oxidation. A plasma can also be used to oxidize NO to NO{sub 2}. This paper compares the multi-stage catalytic scheme with the plasma-assisted catalytic scheme for reduction of NO{sub x} in lean-bum engine exhausts. The advantages of plasma oxidation over catalytic oxidation are presented.
Date: January 26, 1998
Creator: Penetrante, B.M.; Hsiao, M.O.; Merritt, B.T. & Vogling, E.
System: The UNT Digital Library
Ghost analysis visualization techniques for complex systems: examples from the NIF Final Optics Assembly (open access)

Ghost analysis visualization techniques for complex systems: examples from the NIF Final Optics Assembly

The stray light or �ghost� analysis of the National Ignition Facility�s (NIP) Final Optics Assembly (FOA) has proved to be one of the most complex ghost analyses ever attempted. The NIF FOA consists of a bundle of four beam lines that: 1) provides the vacuum seal to the target chamber, 2) converts l(omega) to 3(omega) light, 3) focuses the light on the target, 4) separates a fraction of the 3(omega) beam for energy diagnostics, 5) separates the three wavelengths to diffract unwanted 1(omega) & 2(omega) light away from the target, 6) provides spatial beam smoothing, and 7) provides a debris barrier between the target chamber and the switchyard mirrors. The three wavelengths of light and seven optical elements with three diffractive optic surfaces generate three million ghosts through 4<sup>th</sup> order. Approximately 24,000 of these ghosts have peak fluence exceeding 1 J/cm<sup>2</sup>. The shear number of ghost paths requires a visualization method that allows overlapping ghosts on optics and mechanical components to be summed and then mapped to the optical and mechanical component surfaces in 3D space. This paper addresses the following aspects of the NIF Final Optics Ghost analysis: 1) materials issues for stray light mitigation, 2) limitations of current …
Date: June 26, 1998
Creator: Beer, G. K.; Hendrix, J. L.; Rowe, J. & Schweyen, J.
System: The UNT Digital Library
Spatial filter lens design for the main laser of the National Ignition Facility (open access)

Spatial filter lens design for the main laser of the National Ignition Facility

The National Ignition Facility 0, being designed and constructed at Lawrence Livermore National Laboratory (LLNL), comprises 192 laser beams. The lasing medium is neodymium in phosphate glass with a fundamental frequency (Ice) of 1.053~. Sum frequency generation in a pair of conversion crystals (KDP/KD*P) will produce 1.8 megajoules of the third harmonic light (30 or bO.351~) at the target. The purpose of this paper is to provide the lens design community with the current lens design details of the large powered optics in the Main Laser. This paper describes the lens design configuration and design considerations of the Main Laser. The Main Laser is 123 meters long and includes two spatial tllters: one 23.5 meters and one 60 meters. These spatial filters perform crucial beam filtering and relaying functions. We shall describe the significant lens design aspects of these spatial tilter lenses which allow them to successfully deliver the appropriate beam characteristic onto the target. For a broad overview of NIF. please see, �Optical system design of the National Ignition Facility,� by R. Edward English, et al, also found in this volume.
Date: June 26, 1998
Creator: English, R E; Korniski, R J & Miller, J L
System: The UNT Digital Library
SimTracker - Using the Web to track computer simulation results (open access)

SimTracker - Using the Web to track computer simulation results

Large-scale computer simulations, a hallmark of computing at Lawrence Livermore National Laboratory (LLNL), often take days to run and can produce massive amounts of output. The typical environment of many LLNL scientists includes multiple hardware platforms, a large collection of eclectic software applications, data stored on many devices in many formats, and little standard metadata, which is accessible documentation about the data. The exploration of simulation results typically proceeds as a laborious process requiring knowledge of this complex environment and many application programs. We have addressed this problem by developing a web-based approach for exploring simulation results via the automatic generation of metadata summaries which provide convenient access to the data sets and associated analysis tools. In this paper we will describe the SimTracker tool for automatically generating metadata that serves as a quick overview and index to the archived results of simulations. The SimTracker application consists of two parts - a generation component and a viewing component. The generation component captures and generates calculation metadata from a simulation. These metadata include graphical snapshots from various stages of the run, pointers to the input and output files from the simulation, and assorted annotations describing the run. SimTracker generation can be …
Date: August 26, 1998
Creator: Long, J.; Spencer, P. & Springmeyer, R.
System: The UNT Digital Library
National Ignition Facility main laser stray light analysis and control (open access)

National Ignition Facility main laser stray light analysis and control

Stray light analysis has been carried out for the main laser section of the National Ignition Facility main laser section using a comprehensive non-sequential ray trace model supplemented with additional ray trace and diffraction propagation modeling. This paper describes the analysis and control methodology, gives examples of ghost paths and required tilted lenses, baffles, absorbers, and beam dumps, and discusses analysis of stray light �pencil beams� in the system.
Date: June 26, 1998
Creator: English, R E; Miller, J L; Peterson, G & Schweyen, J
System: The UNT Digital Library
Optical System Design of the National Ignition Facility (open access)

Optical System Design of the National Ignition Facility

The National Ignition Facility (NIF) is a laser fusion facility being constructed at Lawrence Liver-more National Laboratory (LLNL). The neodymium-doped phosphate glass pulsed laser system will produce over 3.5MJ of laser energy at a fundamental lasing wavelength of 1.053pm (1 o). The final optics assembly contains a pair of crystals (KDPKD*P) and a focusing lens to convert the light by sum-frequency-mixing to 30 (h=0,35pm) and focus 1 .SM.J onto the target. The NIF optical system is large and complex. To give some perspective the NIF building is roughly 200 meters long x 85 meters wide. There are approximately 7500 optical components in the large aperture laser system - lenses, mirrors, polarizers, laser slabs, crystals, and windows - each with a clear aperture greater than 4Ocm square. The front-end of the laser system contains more than 8000 smaller (S-l 5cm) precision laser components. In this paper we will describe the optical system configuration, layout, and general design considerations. We will explain the path of the pulse through the various subsystems. Some of the top-level optical system and sub-system design requirements will be pre
Date: June 26, 1998
Creator: English, R E; Laumann, C W; Miller, J L & Seppala, L G
System: The UNT Digital Library
Evaluation of Margins in the ASME Rules for Defining the P-T Curve for a RPV (open access)

Evaluation of Margins in the ASME Rules for Defining the P-T Curve for a RPV

light water reactors
Date: October 26, 1998
Creator: Dickson, T.L.; McAfee, W.J.; Pennell, W.E. & Williams, P.T.
System: The UNT Digital Library
Elegant impulser developed for flat beam injection (open access)

Elegant impulser developed for flat beam injection

The following report describes the design, construction, and checkout of a high-voltage (HV) impulser built for the heavy ion fusion (HIF) project [1]. The purpose of this impulser is to provide an adjustable diode voltage source of sufficient quality and level to allow the optimization of beam transport and accelerator sections of HIF [2, 3]. An elegant, low-impedance, high-energy storage capacitor circuit has been selected for this application. Circuit parameters of the retrofit to the diode region [4] have been included to provide the controlled rise time. The critical part of this circuit that is common to all candidates is the impedance matching component. The following report provides a description of the implemented circuit, the basic circuit variables for wave shaping, screening techniques revealing the weakest circuit component, and the resulting output of the injector.
Date: May 26, 1998
Creator: Wilson, M. J., LLNL
System: The UNT Digital Library
Linear induction accelerator requirements for ion fast ignition (open access)

Linear induction accelerator requirements for ion fast ignition

Fast ignition (fast heating of DT cores afief compression) reduces driver energy (by 10 X or more) by reducing the implosion velocity and energy for a given fuel compression ratio. For any type of driver that can deliver the ignition energy fast enough, fast ignition increases the target gain compared to targets using fast implosions for central ignition, as long as the energy to heat the core after compression is comparable to or less than the slow compression energy, and as long as the coupling efficiency of the fast ignitor beam to heat the core is comparable to the overall efficiency of compressing the core (in terms of beam energy-to-DT-efficiency). Ion driven fast ignition, compared to laser-driven fast ignition, has the advantage of direct (dE/dx) deposition of beam energy to the DT, eliminating inefficiencies for conversion into hot electrons, and direct ion heating also has a more favorable deposition profile with the Bragg-peak near the end of an ion range chosen to be deep inside a compressed DT core. While Petawatt laser experiments at LLNL have demonstrated adequate light-to-hot-electron conversion efficiency, it is not yet known if light and hot electrons can channel deeply enough to heat a small portion …
Date: January 26, 1998
Creator: Logan, G.
System: The UNT Digital Library