An Efficient Microwave Power Source: Free-electron Laser Afterburner (open access)

An Efficient Microwave Power Source: Free-electron Laser Afterburner

A kind of microwave power source, called a free-electron laser afterburner (FEL afterburner) which consists of a free-electron laser buncher and a slow-wave output structure sharing a magnetic wiggler field with the buncher, is proposed. The buncher and the slow-wave structure can operate in either a travelling-wave state or a standing-wave state. In the buncher, the wiggler field together with the radiation field makes an electron beam bunched, and in the slow-wave structure the wiggler field keeps the beam bunched while the bunched beam interacts strongly with the slow-wave structure and so produces rf power. The bunching process comes from the free-electron laser mechanism and the generating process of rf power is in a slow-wave structure. A three-dimensional, time-dependent code is used to simulate a particular standing-wave FEL afterburner and it is shown that rf power of up to 1.57 GW can be obtained, at 17.12 GHz, from a l-kA, 5-MeV electron beam.
Date: March 4, 1993
Creator: Wang, C. & Sessler, Andrew M.
System: The UNT Digital Library
Benefits of recycling galvanized steel scrap for recovery of high-quality steel and zinc metal (open access)

Benefits of recycling galvanized steel scrap for recovery of high-quality steel and zinc metal

Argonne National Laboratory (ANL) and Metal Recovery Industries, Inc. (MRII), in cost-sharing collaboration, have developed an electrolytic process to separate and recover steel and zinc from galvanized steel scrap. This work has been supported by the US DOE. An assessment of available dezinc technology was begun in 1987 which (1) screened process concepts for separating and recovering zinc and steel from galvanized ferrous scrap, (2) selected electrochemical stripping in hot caustic as the most promising process, (3) evaluated the technical and economic feasibility of the selected process on the basis of fundamental electrochemical studies, (4) experimentally verified the technical and economic feasibility of the process in a phased evaluation from bench-scale controlled experiments through batch tests of actual scrap up to six ton lots, and (5) concluded that the process has technical and economic merit and requires larger- scale evaluation in a continuous mode as the final phase of process development. This work has attracted worldwide interest. Preliminary economic analysis indicates that the cost of the recovered ferrous scrap would be about $150/ton (at a base cost of $110/ton for galvanized scrap), including credit for the co-product zinc. Concentrations of zinc, lead, cadmium and other coating constituents on loose scrap …
Date: November 4, 1991
Creator: Dudek, F.J.; Daniels, E.J. (Argonne National Lab., IL (United States)) & Morgan, W.A. (Metal Recovery Industries, Inc., Hamilton, ON (Canada))
System: The UNT Digital Library
A comparative study of short range order in Fe-Cr and Fe-V alloys around equiatomic composition (open access)

A comparative study of short range order in Fe-Cr and Fe-V alloys around equiatomic composition

Configurational energies have been calculated for equiatomic Fe-Cr and Fe-V alloys possessing the high temperature bcc crystalline structure, within a first principles electronic band structure approach. In agreement with experimental facts, a tendency towards order, with a B2 ordered structure of CsCl type, is found for FeV whereas phase separation characterized FeCr. These results suggest that the nature of short range order in the high temperature bcc solid solution is not the primary driving force for describing the structural transformation from bcc to sigma which takes place in both alloys upon decreasing temperature. 15 refs., 9 figs., 1 tab.
Date: December 4, 1990
Creator: Turchi, P.E.A.; Sluiter, M. (Lawrence Livermore National Lab., CA (USA)) & Stocks, G.M. (Oak Ridge National Lab., TN (USA))
System: The UNT Digital Library
Emission assessment from full-scale co-combustion tests of binder- enhanced dRDF pellets and high sulfur coal at Argonne National Laboratory (open access)

Emission assessment from full-scale co-combustion tests of binder- enhanced dRDF pellets and high sulfur coal at Argonne National Laboratory

Argonne National Laboratory (ANL) and University of North Texas (UNT) research teams collected over 800 emissions and ash samples during the combustion of over 650 tons of binder enhanced densified refuse-drived fuel (b-dRDF) pellets with high sulfur coal in a spreader-stoker boiler at ANL. This full-scale test burn was conducted to validate predictions from laboratory and pilot scale test results that indicated substantial reductions of SO{sub 2}, NO{sub x} and CO{sub 2} in the flue gas, and the reduction of heavy metals and organics in the ash residue, when combusting the b-dRDF pellets with coal. Effects of varying fuel composition on performance of the boiler's spray-dryer/fabric filter emissions control system was also evaluated. This paper describes the b-dRDF pellet/coal cofiring tests, the emission and ash samples that were taken, the analyses that were conducted on these samples, and the final test results. 5 refs., 1 fig., 1 tab.
Date: June 4, 1990
Creator: Ohlsson, O. O.; Livengood, C. D. (Argonne National Lab., IL (USA)) & Daugherty, K. E. (University of North Texas, Denton, TX (USA))
System: The UNT Digital Library
Radionuclide limits for vault disposal at the Savannah River Site (open access)

Radionuclide limits for vault disposal at the Savannah River Site

The Savannah River Site is developing a facility called the E-Area Vaults which will serve as the new radioactive waste disposal facility beginning early in 1992. The facility will employ engineered below-grade concrete vaults for disposal and above-grade storage for certain long-lived mobile radionuclides. This report documents the determination of interim upper limits for radionuclide inventories and concentrations which should be allowed in the disposal structures. The work presented here will aid in the development of both waste acceptance criteria and operating limits for the E-Area Vaults. Disposal limits for forty isotopes which comprise the SRS waste streams were determined. The limits are based on total facility and vault inventories for those radionuclides which impact groundwater, and or waste package concentrations for those radionuclides which could affect intruders.
Date: February 4, 1992
Creator: Cook, J. R.
System: The UNT Digital Library
D0 data management (open access)

D0 data management

The management of data in programs for the D0 detector at the FNAL Tevatron collider is described with particular emphasis on aspects relevant to event reconstruction and data analysis. 3 figs.
Date: February 4, 1991
Creator: Protopopescu, S.
System: The UNT Digital Library
Errors when shock waves interact due to numerical shock width (open access)

Errors when shock waves interact due to numerical shock width

A simple test problem proposed by Noh, a strong shock reflecting from a rigid wall, demonstrates a generic problem with numerical shock capturing algorithms at boundaries that Noh called excess wall heating.'' We show that the same type of numerical error occurs in general when shock waves interact. The underlying cause is the non-uniform convergence to the hyperbolic solution of the inviscid limit of the solution to the PDEs with viscosity. The error can be understood from an analysis of the asymptotic solution. For a propagating shock, there is a difference in the total energy of the parabolic wave relative to the hyperbolic shock. Moreover, the relative energy depends on the strength of the shock. The error when shock waves interact is due to the difference in the relative energies between the incoming and outgoing shock waves. It is analogous to a phase shift in a scattering matrix. A conservative differencing scheme correctly describes the Hugoniot jump conditions for a steady propagating shock. Therefore, the error from the asymptotics occurs in the transient when the waves interact. The entropy error that occurs in the interaction region remains localized but does not dissipate. A scaling argument shows that as the viscosity …
Date: March 4, 1993
Creator: Menikoff, R.
System: The UNT Digital Library
Grazing incidence metal mirrors as the final elements in a laser driver for inertial confinement fusion (open access)

Grazing incidence metal mirrors as the final elements in a laser driver for inertial confinement fusion

Grazing incidence metal mirrors (GIMMS) have been examined to replace dielectric mirrors for the final elements in a laser beam line for an inertial confinement fusion (ICF) reactor. For a laser driver using light with a wavelength from 250 to 500 nm in a 10 ns pulse, irradiated mirrors made of Al, Al alloys, or Mg were found to have calculated laser damage limits of 0.3--2.3 J/cm{sup 2} of beam energy and neutron lifetime fluence limits of over 5 {times} 10{sup 20} neutrons per square centimeter when use at grazing incidence (an angle of incidence of 85 degrees) and operated at room temperature or at 77 K. A final focusing system including mirrors made of Al alloy 7475 at room temperature or at liquid nitrogen (LN) temperatures used with a driver which delivers 5 MJ of beam energy in 32 beams would require 32 mirrors of roughly 10 m{sup 2} each. This paper briefly reviews the methods used in calculating the damage limits for GIMMs and discusses critical issues relevant to the integrity and lifetime of such mirrors in a reactor environment. 9 refs.
Date: October 4, 1990
Creator: Bieri, R. L. & Guinan, M. W.
System: The UNT Digital Library
Parametric cost analysis of a HYLIFE-II power plant (open access)

Parametric cost analysis of a HYLIFE-II power plant

The SAFIRE (Systems Analysis for ICF Reactor Economics) code was adapted to model a power plant using a HYLIFE-II reactor chamber. The code was then used to examine the dependence of the plant capital costs and busbar cost of electricity (COE) on a variety of design parameters (type of driver, chamber repetition rate, and net electric power). The results show the most attractive operating space for each set of driver/target assumptions and quantify the benefits of improvements in key design parameters. The base case plant was a 1,000 MWe plant containing a reactor vessel driven by an induction linac heavy ion accelerator run at 7.3 Hz with a driver energy of 5 MJ and a target yield of 370 MJ. The total direct cost for this plant was 2,800 M$ (where all $ in this paper are 1988$s), and the COE was 9 {cents}/KW*hour. The COE and total capital costs for the base plant assumptions for a 1,000 MWe plant are approximately independent of chosen repetition rate for all repetition rates between 4 and 10 Hz. For comparison, the COE for a coal or future fission plant would be 4.5--5.5 {cents}/KW*hour. The COE for a 1,000 MWe plant could be …
Date: October 4, 1990
Creator: Bieri, R.L. (Lawrence Livermore National Lab., CA (USA) Massachusetts Inst. of Tech., Cambridge, MA (USA))
System: The UNT Digital Library
Wake potentials and impedances for the ATA (Advanced Test Accelerator) induction cell (open access)

Wake potentials and impedances for the ATA (Advanced Test Accelerator) induction cell

The AMOS Wakefield Code is used to calculate the impedances of the induction cell used in the Advanced Test Accelerator (ATA) at Livermore. We present the wakefields and impedances for multipoles m = 0, 1 and 2. The ATA cell is calculated to have a maximum transverse impedance of approximately 1000 {Omega}/m at 875 MHz with a quality factor Q = 5. The sensitivity of the impedance spectra to modeling variations is discussed.
Date: September 4, 1990
Creator: Craig, George D.
System: The UNT Digital Library
Laser driven instabilities in inertial confinement fusion (open access)

Laser driven instabilities in inertial confinement fusion

Parametric instabilities excited by an intense electromagnetic wave in a plasma is a fundamental topic relevant to many applications. These applications include laser fusion, heating of magnetically-confined plasmas, ionospheric modification, and even particle acceleration for high energy physics. In laser fusion, these instabilities have proven to play an essential role in the choice of laser wavelength. Characterization and control of the instabilities is an ongoing priority in laser plasma experiments. Recent progress and some important trends will be discussed. 8 figs.
Date: June 4, 1990
Creator: Kruer, W.L.
System: The UNT Digital Library
Reduction of Beam Corkscrew Motion on the ETAII Linear Induction Accelerator (open access)

Reduction of Beam Corkscrew Motion on the ETAII Linear Induction Accelerator

The ETAII linear induction accelerator (6MeV, 3kA, 70ns) is designed to drive a microwave free electron laser (FEL) and demonstrate the front end accelerator technology for a shorter wavelength FEL. Performance to date has been limited by beam corkscrew motion that is driven by energy sweep and misalignment of the solenoidal focusing magnets. Modifications to the pulse power distribution system and magnetic alignment are expected to reduce the radius of corkscrew motion from its present value of 1 cm to less than 1 mm. The modifications have so far been carried out on the first 2.7 MeV (injector plus 20 accelerator cells) and experiments are beginning. In this paper we will present calculations of central flux line alignment, beam corkscrew motion and beam brightness that are anticipated with the modified ETAII. 10 refs., 4 figs., 1 tab.
Date: September 4, 1990
Creator: Turner, W. C.; Allen, S. L.; Brand, H. R.; Caporaso, G. J.; Chambers, F. W.; Chen, Y. J. et al.
System: The UNT Digital Library
Dielectronic recombination measurements at EBIT (Electron Beam Ion Trap) (open access)

Dielectronic recombination measurements at EBIT (Electron Beam Ion Trap)

The Electron Beam Ion Trap at the Lawrence Livermore National Laboratory has proved an ideal device for the study of interactions between electrons and highly-charged ions. I describe measurements of one such interaction, dielectronic recombination, in several ion species. The results are in marginal agreement with theoretical predictions. 8 refs., 6 figs.
Date: October 4, 1990
Creator: Knapp, D.A.
System: The UNT Digital Library
Novel plasma-based frequency upshift methods for short pulse lasers (open access)

Novel plasma-based frequency upshift methods for short pulse lasers

We discuss various novel methods of frequency upshifting short ({le} 1 picosecond) pulses of laser light. All of these methods make use of either the sudden creation of a plasma or relativistic plasma waves. The first method discussed is known as photon acceleration. This method makes use of the fact that a laser pulse moving in a plasma can be thought of as a packet of photons, each possessing an effective mass of m{sub {gamma}} = {h bar}{omega}{sub pe}/c{sup 2} and moving with the group velocity of the laser pulse. These photons experience a force acting on them when in the presence of a gradient in the plasma density. By using a relativistic plasma wave (i.e., a moving density gradient) traveling with the photons, the energy of the photons (thus the frequency) can be continuously increased. We then discuss the sudden creation of a plasma in a region where there exists an electromagnetic wave. This results in a frequency shift of the wave. A similar method is the creation of an ionization front moving near the speed of light, whereby the interaction of this plasma front with an EM wave also results in a frequency upshift of the original wave. …
Date: June 4, 1990
Creator: Wilks, S.C. (Lawrence Livermore National Lab., CA (USA)); Dawson, J.M. & Mori, W.B. (California Univ., Los Angeles, CA (USA). Dept. of Physics)
System: The UNT Digital Library
Status Report on Fermilab Experiment E-760: A Study of Charmonium Produced by Proton-Antiproton Annihilation (open access)

Status Report on Fermilab Experiment E-760: A Study of Charmonium Produced by Proton-Antiproton Annihilation

This was a status report on Fermilab experiment E-760 -- an experiment to study charmonium states by resonant formation in proton-antiproton annihilation. The experiment uses antiprotons circulating in the Fermilab antiproton-accumulator as the beam and an internal hydrogen gas-jet as the target. Data taking with the full complement of apparatus started in early July 1990.
Date: September 4, 1990
Creator: Pordes, Stephen
System: The UNT Digital Library
Oscillating liquid flow ICF (inertial confinement fusion) reactor (open access)

Oscillating liquid flow ICF (inertial confinement fusion) reactor

Oscillating liquid flow in a falling molten salt inertial confinement fusion reactor is predicted to rapidly clear driver beam paths of residual molten salt. Oscillating flow will also provide adequate neutron and x-ray protection for the reactor structure with a short (2-m) fall distance permitting an 8 Hz repetition rate. A reactor chamber configuration is presented with specific features to clear the entire heavy-ion beam path of splashed molten salt. The structural components, including the structure between beam ports, are shielded. 3 refs., 12 figs.
Date: October 4, 1990
Creator: Petzoldt, R.W.
System: The UNT Digital Library
Chemical kinetic modeling of chlorinated hydrocarbons under stirred-reactor conditions (open access)

Chemical kinetic modeling of chlorinated hydrocarbons under stirred-reactor conditions

The combustin of chloroethane is modeled as a stirred reactor so that we can study critical emission characteristics of the reactor as a function of residence time. We examine important operating conditions such as pressure, temperature, and equivalence ratio and their influence on destructive efficiency of chloroethane and production of other chlorinated products. The model uses a detailed chemical kinetic mechanism that we have developed previously for C{sub 3} hydrocarbons. We have added to this mechanism the chemical kinetic mechanism for C{sub 2} chlorinated hydrocarbons developed by Senkan and coworkers. Some reactions have been added to Senkan's mechanism and some of the reaction-rate expressions have been updated to reflect recent developments in the literature. In the modeling calculations, sensitivity coefficients are determined to find which reaction-rate constants have the largest effect on destructive efficiency. 25 refs., 6 figs., 1 tab.
Date: October 4, 1990
Creator: Pitz, W.J. & Westbrook, C.K.
System: The UNT Digital Library
HYLIFE-2 inertial confinement fusion reactor design (open access)

HYLIFE-2 inertial confinement fusion reactor design

The HYLIFE-II inertial fusion power plant design study uses a liquid fall, in the form of jets to protect the first structural wall from neutron damage, x-rays, and blast to provide a 30-y lifetime. HYLIFE-I used liquid lithium. HYLIFE-II avoids the fire hazard of lithium by using a molten salt composed of fluorine, lithium, and beryllium (Li{sub 2}BeF{sub 4}) called Flibe. Access for heavy-ion beams is provided. Calculations for assumed heavy-ion beam performance show a nominal gain of 70 at 5 MJ producing 350 MJ, about 5.2 times less yield than the 1.8 GJ from a driver energy of 4.5 MJ with gain of 400 for HYLIFE-I. The nominal 1 GWe of power can be maintained by increasing the repetition rate by a factor of about 5.2, from 1.5 to 8 Hz. A higher repetition rate requires faster re-establishment of the jets after a shot, which can be accomplished in part by decreasing the jet fall height and increasing the jet flow velocity. Multiple chambers may be required. In addition, although not considered for HYLIFE-I, there is undoubtedly liquid splash that must be forcibly cleared because gravity is too slow, especially at high repetition rates. Splash removal can be accomplished …
Date: October 4, 1990
Creator: Moir, Ralph W.
System: The UNT Digital Library
Soft x-ray detection with diamond photoconductive detectors (open access)

Soft x-ray detection with diamond photoconductive detectors

Photoconductive detectors fabricated from natural lla diamonds have been used to measure the x-ray power emitted from laser produced plasmas. The detector was operated without any absorbing filters to distort the x-ray power measurement. The 5.5 eV bandgap of the detector material practically eliminates its sensitivity to scattered laser radiation thus permitting filterless operation. The detector response time or carrier life time was 90 ps. Excellent agreement was achieved between a diamond PCD and a multichannel photoemissive diode array in the measurement of radiated x-ray power and energy. 4 figs.
Date: May 4, 1990
Creator: Kania, D. R.; Pan, L.; Kornblum, H.; Bell, P.; Landen, O. N. & Pianetta, P.
System: The UNT Digital Library
The origins of ordering in CuPt (open access)

The origins of ordering in CuPt

The alloy CuPt is one of the few that order into a L1{sub 1} crystal structure, i.e. planes of copper and planes of planes of planes of platinum perpendicular to the < 111 > direction. For disordered CuPt, the calculated Warren-Cowley short-range order parameter indicates an instability to concentration fluctuations with a wave-vector of ({1/2}, {1/2}, {1/2}), consistent with L1{sub 1} ordering. We show that this rare tendency is due to this ordering vector arising from the large joint density of states associated with L point and X point van-Hove singularities which lie near the Fermi energy.
Date: August 4, 1993
Creator: Clark, J. F.; Pinski, F. J.; Sterne, P. A.; Johnson, D. D.; Staunton, J. B. & Ginatempo, B.
System: The UNT Digital Library
Benefits of recycling galvanized steel scrap for recovery of high-quality steel and zinc metal (open access)

Benefits of recycling galvanized steel scrap for recovery of high-quality steel and zinc metal

Argonne National Laboratory (ANL) and Metal Recovery Industries, Inc. (MRII), in cost-sharing collaboration, have developed an electrolytic process to separate and recover steel and zinc from galvanized steel scrap. This work has been supported by the US DOE. An assessment of available dezinc technology was begun in 1987 which (1) screened process concepts for separating and recovering zinc and steel from galvanized ferrous scrap, (2) selected electrochemical stripping in hot caustic as the most promising process, (3) evaluated the technical and economic feasibility of the selected process on the basis of fundamental electrochemical studies, (4) experimentally verified the technical and economic feasibility of the process in a phased evaluation from bench-scale controlled experiments through batch tests of actual scrap up to six ton lots, and (5) concluded that the process has technical and economic merit and requires larger- scale evaluation in a continuous mode as the final phase of process development. This work has attracted worldwide interest. Preliminary economic analysis indicates that the cost of the recovered ferrous scrap would be about $150/ton (at a base cost of $110/ton for galvanized scrap), including credit for the co-product zinc. Concentrations of zinc, lead, cadmium and other coating constituents on loose scrap …
Date: November 4, 1991
Creator: Dudek, F. J.; Daniels, E. J. & Morgan, W. A.
System: The UNT Digital Library
Particle tracking in E {minus} {phi} space for synchrotron design and diagnosis (open access)

Particle tracking in E {minus} {phi} space for synchrotron design and diagnosis

The single particle equations for the longitudinal motion in a synchrotron can be faithfully represented as a one-turn mapping of a particle`s phase space position relative to the synchronous particle. Applied to a distribution of particles, the mapping can be used to model the evolution of bunches to test beam manipulations or to extract the time dependence of quantities like the bunching factor, momentum spread, etc. which can be difficult to calculate. Such modelling requires rather few representative particles, permitting numerical experimentation and exploratory design trials. By modifying the mapping each turn to introduce the collective effects of the distribution, one can model such processes as phase feedback, space-charge effects, coupled bunch motion, etc. Calculations of this type offer quantitative performance predictions, aid diagnosis of existing accelerators, and contribute to the understanding of the underlying dynamics. This talk introduces the tools and some illustrations.
Date: November 4, 1992
Creator: MacLachlan, J. A.
System: The UNT Digital Library
Radionuclide Limits for Vault Disposal at the Savannah River Site (open access)

Radionuclide Limits for Vault Disposal at the Savannah River Site

The Savannah River Site is developing a facility called the E-Area Vaults which will serve as the new radioactive waste disposal facility beginning early in 1992. The facility will employ engineered below-grade concrete vaults for disposal and above-grade storage for certain long-lived mobile radionuclides. This report documents the determination of interim upper limits for radionuclide inventories and concentrations which should be allowed in the disposal structures. The work presented here will aid in the development of both waste acceptance criteria and operating limits for the E-Area Vaults. Disposal limits for forty isotopes which comprise the SRS waste streams were determined. The limits are based on total facility and vault inventories for those radionuclides which impact groundwater, and or waste package concentrations for those radionuclides which could affect intruders.
Date: February 4, 1992
Creator: Cook, J. R.
System: The UNT Digital Library
Federal and state regulatory requirements for the D&D of the Alpha-4 Building, Y-12 Plant, Oak Ridge, Tennessee (open access)

Federal and state regulatory requirements for the D&D of the Alpha-4 Building, Y-12 Plant, Oak Ridge, Tennessee

The US Department of Energy (DOE) has begun the decontamination and decommissioning (D&D) of Building 9201-4 (Alpha-4) at the Oak Y-12 Plant, Oak Ridge, Tennessee, The Alpha-4 Building was used from 1953--1962 to house a column exchange (Colex) process for lithium isotope separation. This process involved electrochemical and solvent extraction processes that required substantial quantities of mercury. Presently there is no law or regulation mandating decommissioning at DOE facilites or setting de minimis or ``below regulatory concern`` (BRC) radioactivity levels to guide decommissioning activities at DOE facilities. However, DOE Order 5820.2A, Chap. V (Decommissioning of Radioactively Contaminated Facilities), requires that the regulatory status of each project be identified and that technical engineering planning must assure D&D compliance with all environmental regulations during cleanup activities. To assist in the performance of this requirement, this paper gives a brief overview of potential federal and state regulatory requirements related to D&D activities at Alpha-4. Compliance with other federal, state, and local regulations not addressed here may be required, depending on site characterization, actual D&D activities, and wastes generated.
Date: March 4, 1994
Creator: Etnier, E. L.; Houlberg, L. M. & Bock, R. E.
System: The UNT Digital Library