The U5. 0 Undulator for the ALS (open access)

The U5. 0 Undulator for the ALS

the U5.0 Undulator, and 89 period, 5 cm period length, 4.6 m long insertion device has been designed, is being fabricated and is scheduled for completion in early 1992. This undulator will be the first high brightness source, in the 50 to 1500 eV range, for the Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory. A hybrid magnetic configuration using Nd-Fe-B permanent magnet material and vanadium permendur poles has been selected to achieve the field quality needed to meet performance requirements. The magnetic structure is modular with each half consisting of 5 assembly sections, which provide the periodic structure, and end structures, for entrance and exit correction, mounted on a steel backing beam. Each assembly section consists of 35 half-period pole assemblies bolted to a mount. The required 0.837 Tesla effective peak field at a 1.4 cm gap has been verified with model measurements. Vertical field integral correction is accomplished with the end structures, each having an arrangement of permanent magnet rotors which will be adjusted to minimize electron beam missteering over the undulator operating field range. To reduce the effect of environmental fields, the steel backing beams are connected through parallel, low-reluctance, Ni-Fe hinges. The magnetic structure is …
Date: July 15, 1991
Creator: Hoyer, E.; Chin, J.; Halbach, K.; Hassenzahl, W.V.; Humphries, D.; Kincaid, B. et al.
System: The UNT Digital Library
Space propulsion by fusion in a magnetic dipole (open access)

Space propulsion by fusion in a magnetic dipole

The unique advantages of fusion rocket propulsion systems for distant missions are explored using the magnetic dipole configurations as an example. The dipole is found to have features well suited to space applications. Parameters are presented for a system producing a specific power of kW/kg, capable of interplanetary flights to Mars in 90 days and to Jupiter in a year, and of extra-solar-system flights to 1000 astronomical units (the Tau mission) in 20 years. This is about 10 times better specific power performance than nuclear electric fission systems. Possibilities to further increase the specific power toward 10 kW/kg are discussed, as is an approach to implementing the concept through proof-testing on the moon. 20 refs., 14 figs., 2 tabs.
Date: July 15, 1991
Creator: Teller, E.; Glass, A.J.; Fowler, T.K. (Lawrence Livermore National Lab., CA (United States)); Hasegawa, A. (AT and T Bell Labs., Murray Hill, NJ (United States)) & Santarius, J.F. (Wisconsin Univ., Madison, WI (United States). Fusion Technology Inst.)
System: The UNT Digital Library
Safety questions relevant to nuclear thermal propulsion (open access)

Safety questions relevant to nuclear thermal propulsion

Nuclear propulsion is necessary for successful Mars exploration to enhance crew safety and reduce mission costs. Safety concerns are considered by some to be an implements to the use of nuclear thermal rockets for these missions. Therefore, an assessment was made of the various types of possible accident conditions that might occur and whether design or operational solutions exist. With the previous work on the NERVA nuclear rocket, most of the issues have been addressed in some detail. Thus, a large data base exist to use in an agreement. The assessment includes evaluating both ground, launch, space operations and disposal conditions. The conclusion is that design and operational solutions do exist for the safe use of nuclear thermal rockets and that both the environment and crews be protected against harmful radiation. Further, it is concluded that the use of nuclear thermal propulsion will reduce the radiation and mission risks to the Mars crews.
Date: October 15, 1991
Creator: Buden, D.
System: The UNT Digital Library
The industrial consortium for the utilization of the geopressured-geothermal resource (open access)

The industrial consortium for the utilization of the geopressured-geothermal resource

Four feasibility studies have been developed by the INEL on thermal enhanced oil recovery (TEOR) Use of Supercritical Fluid processes for Detoxification of Pollutants, and Hydraulic Conversion to Electricity, and Direct Use. The studies provide information bases for potential industrial partners in the resource utilization. A joint proposal from Los Alamos National Laboratory (LANL) and INEL on supercritical fluid processes in going forward. Western Resources Technology has begun development of a dozen geopressured well projects. An hydraulic turbine test will be conducted at Pleasant Bayou in Summer of 1991. Dr. Wayne Steele of Anglewood, TX, a retired medical doctor, is proposing to raise fresh water Australian lobsters in the Pleasant Bayou Well fire water pond. Additional projects such as catfish farming, crayfish, desalintion plant and agricultural greenhouse use of the resource heat are waiting in the wings'' for the DOE wells to become available for pilot use projects. 2 figs.
Date: February 15, 1991
Creator: Negus-de Wys, J.
System: The UNT Digital Library
Superconducting Magnets for a Muon Collider (open access)

Superconducting Magnets for a Muon Collider

None
Date: February 15, 1996
Creator: Green, Michael A.
System: The UNT Digital Library
Localized or Systemic {italic In Vivo} Heat-Inactivation of Human Immunodeficiency Virus (HIV): A Mathematical Analysis (open access)

Localized or Systemic {italic In Vivo} Heat-Inactivation of Human Immunodeficiency Virus (HIV): A Mathematical Analysis

Temperatures as low as 42 C, maintained for a little as 25 minutes, inactivate {approx}25% of HIV. Furthermore, human immunodeficiency virus (HIV)-infected T-cells are more sensitive to heat than healthy lymphocytes and susceptibility increases when the cells are pre-sensitized by exposure to tumor necrosis factor. Thus, induction of a whole-body hyperthermia, or hyperthermia specifically limited to tissues having a high viral load, are potential antiviral therapies for acquired immunodeficiency disease (AIDS). Accordingly, we incorporated therapeutic hyperthermia into an existing mathematical model which evaluates the interaction between HIV and CD4{sup +} T cells. Given the assumptions and limitations of this model, the results indicate that a daily therapy, reducing the population of actively infected cells by 40% or infectious virus by 50%, would effectively reverse the depletion of T cells. In contrast, a daily reduction of 20% of either actively infected cells or infectious virus would have a marginal effect. However, reduction by 20% of both actively infected cells and infectious virus could restore T cell numbers, assuming that permanent damage had not been inflicted on the thymus. Whole-body hyperthermia seems unlikely to be clinically useful, unless it can be induced non-invasively without general anesthesia. In contrast, heating directed specifically to …
Date: December 15, 1993
Creator: Pennypacker, Carl R.; Perelson, A.S.; Nys, N.; Nelson, G. & Sessler, D.I.
System: The UNT Digital Library
The Elimination of Oxides of Nitrogen from the Exhaust of a dieselEngine using cryogenic air separation (open access)

The Elimination of Oxides of Nitrogen from the Exhaust of a dieselEngine using cryogenic air separation

None
Date: August 15, 1997
Creator: Manikowski, A.; Noland, G. & Green, M. A.
System: The UNT Digital Library
A Design Method for Multiple Tube Gas-Cooled Electrical Leads forthe g-2 Superconducting Magnets (open access)

A Design Method for Multiple Tube Gas-Cooled Electrical Leads forthe g-2 Superconducting Magnets

None
Date: December 15, 1994
Creator: Green, M. A.; Jia, L. X.; Addessi, L. J.; Cullen, J. R.; Esper, A. J. & and Meier, R. E.
System: The UNT Digital Library
A Fuel Cell Power Supply for Long Duration Balloon Flights UsingStored Cryogens (open access)

A Fuel Cell Power Supply for Long Duration Balloon Flights UsingStored Cryogens

None
Date: August 15, 1997
Creator: Green, Michael A.; Manikowski, A.; Noland, G. & Golden, R.L.
System: The UNT Digital Library
A site scale model for modeling unsaturated zone processes atYucca Mountain, Nevada (open access)

A site scale model for modeling unsaturated zone processes atYucca Mountain, Nevada

None
Date: December 15, 1997
Creator: Bodvarsson, G.S.; Wu, Y.S.; Sonnenthal, E.L.; Bandurraga, T.M.; Ahlers, C.F.; Haukwa, C. et al.
System: The UNT Digital Library
Space nuclear power requirements for ozone layer modification (open access)

Space nuclear power requirements for ozone layer modification

This work estimates the power requirements for using photochemical processes driven by space nuclear power to counteract the Earth's ozone layer depletion. The total quantity of ozone (O{sub 3}) in the Earth's atmosphere is estimated to be about 4.7 {times} 10{sup 37} molecules. The ozone production and destruction rates in the stratosphere are both on the order of 4.9 {times} 10{sup 31} molecules/s, differing by a small fraction so that the net depletion rate is about 0.16 to 0.26% per year. The delivered optical power requirement for offsetting this depletion is estimated to be on the order of 3 GW. If the power were produced by satellite reactors at 800 km altitude (orbit decay time {approximately} 300 years), some means of efficient power beaming would be needed to deliver the power to stratospheric levels (10--50 km). Ultraviolet radiation at 140--150 nm could have higher absorption rates in O{sub 2} (leading to production of atomic oxygen, which can combine with O{sub 2} to form O{sub 3}) than in ozone (leading to photodissociation of O{sub 3}). Potential radiation sources include H{sub 2} lasers and direct nuclear pumping of ultraviolet fluorescers. 5 refs.
Date: October 15, 1991
Creator: Dolan, T.J.
System: The UNT Digital Library
Iridium alloy clad vent set manufacturing qualification studies (open access)

Iridium alloy clad vent set manufacturing qualification studies

In 1987 the Department of Energy-Office of Special Applications (DOE-OSA) decided to transfer the iridium alloy Clad Vent Set (CVS) manufacturing for the General Purpose Heat Source (GPHS) program from EG G Mound Applied Technologies, Inc. (EG G-MAT) to the Oak Ridge Y-12 Plant operated by Martin Marietta Energy Systems, Inc. (Energy Systems). The reason for this transfer was to consolidate the GPHS program iridium hardware manufacturing. The CVS starting stock of iridium powder, foil, and blanks were already being manufactured at another Energy Systems facility - the Oak Ridge National Laboratory (ORNL). Since 1987 CVS manufacturing technology transfer efforts have taken place between EG G-MAT and Energy Systems. EG G-MAT retained all of their tooling, but they supplied all the necessary product drawings, specifications, and procedures, as well as their tooling drawings. Most of the tooling designs and processing steps were duplicated at the Y-12 Plant. Minor changes were required in both tooling design and processing steps, to accommodate particular health, safety, environmental, and manufacturing requirements at the Y-12 Plant. In order to evaluate the effects of the key Y-12 Plant processing modifications, four joint Y-12 Plant/EG G-MAT iridium CVS manufacturing qualification studies were organized. The successful completion of …
Date: June 15, 1990
Creator: Ulrich, G.B.
System: The UNT Digital Library
Identification and initial assessment of candidate BWR late-phase in-vessel accident management strategies (open access)

Identification and initial assessment of candidate BWR late-phase in-vessel accident management strategies

Work sponsored by the United States Nuclear Regulatory Commission (USNRC) to identify and perform preliminary assessments of candidate BWR (boiling water reactor) in-vessel accident management strategies was completed at Oak Ridge National Laboratory (ORNL) during fiscal year 1990. Mitigative strategies for containment events have been the subject of a companion study at Brookhaven National Laboratory. The focus of this Oak Ridge effort was the development of new strategies for mitigation of the late phase events, that is, the events that would occur in-vessel after the onset of significant core damage. The work began with an investigation of the current status of BWR in-vessel accident management procedures and proceeded through a preliminary evaluation of several candidate new strategies. The steps leading to the identification of the candidate strategies are described. The four new candidate late-phase (in-vessel) accident mitigation strategies identified by this study and discussed in the report are: (1) keep the reactor vessel depressurized; (2) restore injection in a controlled manner; (3) inject boron if control blade damage has occurred; and (4) containment flooding to maintain core and structural debris in-vessel. Additional assessments of these strategies are proposed.
Date: April 15, 1991
Creator: Hodge, S.A.
System: The UNT Digital Library
Varied line-space gratings and applications (open access)

Varied line-space gratings and applications

This paper presents a straightforward analytical and numerical method for the design of a specific type of varied line-space grating system. The mathematical development will assume plane or nearly-plane spherical gratings which are illuminated by convergent light, which covers many interesting cases for synchrotron radiation. The gratings discussed will have straight grooves whose spacing varies across the principal plane of the grating. Focal relationships and formulae for the optical grating-pole-to-exist-slit distance and grating radius previously presented by other authors will be derived with a symbolic algebra system. It is intended to provide the optical designer with the tools necessary to design such a system properly. Finally, some possible advantages and disadvantages for application to synchrotron to synchrotron radiation beamlines will be discussed.
Date: July 15, 1991
Creator: McKinney, W.R.
System: The UNT Digital Library
Emittance measurement in a magnetic field (open access)

Emittance measurement in a magnetic field

Emittance can be measured by intercepting an electron beam on a range thick plate and then observing the expansion of beamlets transmitted through small holes. The hole size is selected to minimize space charge effects. In the presence of a magnetic field the beamlets have a spiral trajectory and the usual field free formulation must be modified. To interpret emittance in the presence of a magnetic field an envelope equation is derived in the appropriate rotating frame. 1 ref.
Date: April 15, 1991
Creator: Boyd, J.K.
System: The UNT Digital Library
Simulations of NOVA direct-drive hydrodynamics experiments (open access)

Simulations of NOVA direct-drive hydrodynamics experiments

Directly driven Rayleigh-Taylor instability growth experiments being performed on NOVA have been simulated using the computer code, LASNEX. Foils with single-wavelength imposed surface perturbations have been driven with a single beam of 0.53 {mu}m light, employing smoothing by spectral dispersion (SSD). In addition to simulating foils with imposed surface perturbations, we have simulated flat foils driven by beams with time-dependent intensity modulation resulting from the NOVA implementation of SSD. These simulations show the development of large amplitude modulation of the target from residual intensity nonuniformities. Structure seeded by beam nonuniformity would overwhelm modulation resulting from imposed surface perturbations of sub-micron initial amplitude, but is predicted to develop sufficiently slowly that we expect to observe growth of perturbations with initial amplitudes of several microns. In other NOVA experiments, flat foils with an embedded brominated spectroscopic tracer layer are used in infer mass ablation rates. SSD drive is predicted to yield ablation rates in better agreement with 1-D simulations than drive from a beam with random phase plates (RPP) alone. Simulations of foils driven with RPP beams show enhanced ablation rates because modulation of the ablation front increases its surface area. Line emission from the seed is first seen at cold spots …
Date: April 15, 1991
Creator: Weber, S. V, & Glendinning, S. G.
System: The UNT Digital Library
The single antenna interferometer (open access)

The single antenna interferometer

Air and space borne platforms using synthetic aperture radars (SAR) have made interferometric measurements by using either two physical antennas mounted on one air-frame or two passes of one antenna over a scene. In this paper, a new interferometric technique using one pass of a single-antenna SAR system is proposed and demonstrated on data collected by the NASA-JPL AirSAR. Remotely sensed L-band microwave data are used to show the sensitivity of this technique to ocean surface features as well as a baseline for comparison with work by others using two-antenna systems. 7 refs., 3 figs.
Date: January 15, 1990
Creator: Fitch, J.P.
System: The UNT Digital Library
Physics issues in the design of a recirculating induction accelerator for heavy ion fusion (open access)

Physics issues in the design of a recirculating induction accelerator for heavy ion fusion

A substantial savings in size and cost over a linear machine may be achieved in an induction accelerator in which a heavy ion beam makes many (< {approximately} 50) passes through one or more circular induction accelerators. We examine how the requirement of high beam quality and the requirement of pulse simultaneity at the target constrain the design of such an accelerator. Some of the issues that we have considered include beam interactions with residual gas, beam-beam charge exchange, emittance growth around bends, and beam instabilities. We show some of the interplay between maximization of beam quality and recirculator efficiency, and the minimization of recirculator cost, in arriving at a recirculator design. 9 refs., 1 fig.
Date: April 15, 1991
Creator: Barnard, J. J.; Newton, M. A.; Reginato, L. L.; Sharp, W. M. & Yu, S. S.
System: The UNT Digital Library
Analysis of spherical geometry finite element transport solutions in the thick diffusion limit (open access)

Analysis of spherical geometry finite element transport solutions in the thick diffusion limit

An asymptotic analysis if performed on a family of discontinuous finite element methods (DFEMs) for spherical geometry transport. It is found that transport methods of this type transition into discrete versions of the spherical geometry diffusion equation in the thick diffusion limit with boundary conditions that may, in general, be inaccurate. A linear DFEM method has been designed such that its asymptotic diffusion boundary conditions are accurate. In a related development, the asymptotic diffusion equation is used to accelerate the transport calculation and the iterative scheme is fully described. The results of the analysis are confirmed by numerical testing of the specific case of linear elements. 5 refs., 2 figs., 1 tab.
Date: January 15, 1991
Creator: Palmer, T.S. (Michigan Univ., Ann Arbor, MI (USA). Dept. of Nuclear Engineering) & Adams, M.L. (Lawrence Livermore National Lab., CA (USA))
System: The UNT Digital Library
ASSESS (Analytic System and Software for Evaluating Safeguards and Security) update: Current status and future developments (open access)

ASSESS (Analytic System and Software for Evaluating Safeguards and Security) update: Current status and future developments

The Analytic System and Software for Evaluating Safeguards and Security (ASSESS) has been released for use by DOE field offices and their contractors. In October, 1989, we offered a prototype workshop to selected representatives of the DOE community. Based on the prototype results, we held the first training workshop at the Central Training Academy in January, 1990. Four additional workshops are scheduled for FY 1990. ASSESS is a state-of-the-art analytical tool for management to conduct integrated evaluation of safeguards systems at facilities handling facilities. Currently, ASSESS focuses on the threat of theft/diversion of special nuclear material by insiders, outsiders, and a special form of insider/outsider collusion. ASSESS also includes a neutralization module. Development of the tool is continuing. Plans are underway to expand the capabilities of ASSESS to evaluate against violent insiders, to validate the databases, to expand the neutralization module, and to assist in demonstrating compliance with DOE Material Control and Accountability (MC A) Order 5633.3. These new capabilities include the ability to: compute a weighted average for performance capability against a spectrum of insider adversaries; conduct defense-in-depth analyses; and analyze against protracted theft scenarios. As they become available, these capabilities will be incorporated in our training program. ASSESS …
Date: July 15, 1990
Creator: Al-Ayat, R.A. (Lawrence Livermore National Lab., CA (USA)); Cousins, T.D. (USDOE, Washington, DC (USA)) & Hoover, E.R. (Sandia National Labs., Albuquerque, NM (USA))
System: The UNT Digital Library
Calculated Non-Linear Magnetic Field Penetration of Plasma Opening Switches (open access)

Calculated Non-Linear Magnetic Field Penetration of Plasma Opening Switches

We examine magnetic field penetration in the Plasma Opening Switch, exploring, in particular, advective field penetration arising in conjunction with radial density gradients across the cathode anode gap. Our calculations have been completed with the implicit multi-fluid, ANTHEM code. We show favored penetration along a radial density jump, unstable plain wave penetration for a 1/(y {minus} y{sub {alpha}+{epsilon}}) density dependence (with y measured from cathode to anode at Y{sub {alpha}}) in planar switches, and the penetration of finger-like magnetic field perturbations, when the fill plasmas bears initial sinusoidal disturbances on its generator interface. 7 refs., 4 figs.
Date: June 15, 1990
Creator: Mason, R. J.; Jones, M. E.; Wilson, D. C.; Bergman, C.; Thiem, K.; Grossmann, J. M. et al.
System: The UNT Digital Library
Study of intermittency in e sup + e sup minus annihilations at 29 GeV (open access)

Study of intermittency in e sup + e sup minus annihilations at 29 GeV

Charged particle multiplicity distributions from e{sup +}e{sup {minus}} annihilations at 29 GeV have been analyzed in selected rapidity and azimuthal angle intervals. The data were taken with the High Resolution Spectrometer at PEP. The factorial moments of the multiplicity distributions increase as the rapidity interval is decreased, the so-called intermittency phenomenon. These direct measurements of the moments agree with values derived from negative binomial fits to our multiplicity distributions in various central rapidity windows. The factorial moments are also given for the distribution in azimuthal angle around the beam direction and for the two-dimensional distribution in rapidity and azimuthal angle around the jet directions.
Date: June 15, 1990
Creator: Abachi, S.; Derrick, M.; Kooijman, P.; Musgrave, B.; Price, L.; Repond, J. et al.
System: The UNT Digital Library
Fast pulsars, strange stars: An opportunity in radio astronomy (open access)

Fast pulsars, strange stars: An opportunity in radio astronomy

The world's data on radio pulsars is not expected to represent the underlying pulsar population because of a search bias against detection of short periods, especially below 1 ms. Yet pulsars in increasing numbers with periods right down to this limit have been discovered suggesting that there may be even shorter ones. If pulsars with periods below 1/2 ms were found, the conclusion that the confined hadronic phase of nucleons and nuclei is only metastable would be almost inescapable. The plausible ground state in that event is the deconfined phase of (3-flavor) strange-quark-matter. From the QCD energy scale this is as likely a ground state as the confined phase. We show that strange matter as the ground state is not ruled out by any known fact, and most especially not by the fact that the universe is in the confined phase. 136 refs.
Date: July 15, 1990
Creator: Glendenning, N.K.
System: The UNT Digital Library
Order-disorder phenomena in complex alloys: The case of A15-based substitutional alloys (open access)

Order-disorder phenomena in complex alloys: The case of A15-based substitutional alloys

We first discuss the applicability of the Generalized Perturbation Method to the study of ordering phenomena in complex alloys for which stability properties are electronically driven. In particular, according to previous work, it is recalled that a 3D-generalized Ising model is appropriate to address the problem of configurational order in A15-based substitutional alloys. A ground state analysis of this model, including 1st, 2nd, and weak 3rd and 7th pair interactions, generates two new ordered states at the composition A{sub 5}B{sub 3} and A{sub 7}B, apart from the well known A{sub 3}B configuration. The stability of these predicted configurations is examined as a function of temperature and concentration by means of standard statistical techniques. The results are discussed in relation with the experimental situation. 11 refs., 4 figs.
Date: August 15, 1990
Creator: Turchi, P.E.A. (Lawrence Livermore National Lab., CA (USA)) & Finel, A. (Office National d'Etudes et de Recherches Aerospatiales (ONERA), 92 - Chatillon (France))
System: The UNT Digital Library