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Nature and effects of ion-cyclotron fluctuations in TMX (open access)

Nature and effects of ion-cyclotron fluctuations in TMX

In the tandem mirror experiment (TMX), coherent oscillations have been identified as resulting from the Alfven ion-cyclotron instability. Although the drive for this instability is localized in the end cell, the waves generated propagate out of the unstable region and interact with the central-cell ions. This interaction leads to an experimentally observed scaling of the stored end-cell energy with axial ion end-loss current.
Date: February 19, 1982
Creator: Casper, T. A.; Poulsen, P. & Smith, G. R.
System: The UNT Digital Library
Ion-beam inertial fusion: the requirements posed by target and deposition physics (open access)

Ion-beam inertial fusion: the requirements posed by target and deposition physics

The demonstration of ICF scientific feasibility requires success in target design, driver development and target fabrication. Since these are interrelated, we present here some results of ion beam target studies and relate them to parameters of interest to ion accelerators. Ion deposition physics have long been a well known subject apart from high beam currents. Recent NRL experiments at up to 250 kA/cm/sup 2/ ions confirm the classical deposition physics now at current densities which are comparable to most ion targets. On the other hand, GSI data at low current density but 1 to 10 MeV/nucleon are continually being accumulated. They have yet to find anomalous results. Relying on target concepts outlined briefly, we report on the energy gain of ion-driven fusion targets as a function of input energy, ion ranges and focal spot radius. We also comment on some consequences of target gain versus driver and reactor requirements.
Date: October 19, 1981
Creator: Mark, J.W.K.
System: The UNT Digital Library
Performance of a Nova beamline with high damage threshold glass (open access)

Performance of a Nova beamline with high damage threshold glass

We report on measurements made on a Nova beamline whose output amplifier stages contain new high damage threshold, platinum particle-free laser glass. We project future operating limits for the Nova ten beam amplifier system. 4 refs.
Date: November 19, 1987
Creator: Bibeau, C.; Ehrlich, R. B.; Lawson, J. K.; Laumann, C. W.; Pennington, D. M.; Weiland, T. L. et al.
System: The UNT Digital Library
Design and implementation of a fiber-optic gamma-measurement system (open access)

Design and implementation of a fiber-optic gamma-measurement system

The design and implementation of the downhole portion of a measuring system for gamma rays is presented. Included are three alternative designs for radiation-resistant collimating and condensing lenses, sample cells, turning mirrors, and fiber-optic termination techniques. Also discussed are mechanical mounts and positioners, shielding, alignment, test methods, and field installation. Some general design suggestions for optical systems in adverse environments are also presented.
Date: May 19, 1980
Creator: Reedy, R.P.; Crawford, D.W. & Roeske, F. Jr.
System: The UNT Digital Library
Explosive vaporization of small droplets (open access)

Explosive vaporization of small droplets

A model has been created of the explosive vaporization of small droplets by the absorption of energy from a high energy laser beam. The model consists of a polarizable drop of fluid interacting with laser radiation. A criterion for the explosion of the droplet has been introduced. Selfsimilarity is invoked to reduce the spherically symmetric problem involving hydrodynamics and Maxwell's equations to simple quadrature. Experimental evidence in favor of the model is cited.
Date: August 19, 1986
Creator: Chitanvis, S.M.
System: The UNT Digital Library
Neutron capture studies: 1, Multiple capture reactions and implications for calculated beta-delayed fission rates: 2, The nuclear level structure of 238Np (open access)

Neutron capture studies: 1, Multiple capture reactions and implications for calculated beta-delayed fission rates: 2, The nuclear level structure of 238Np

Astrophysical r-process calculations of transbismuth elements are of interest because certain actinide pairs can be treated as chronometers in determining the duration of nucleosynthesis. For one such calculation where a particularly long galactic age was derived, 21 + 2 - 4 Gyr, we present evidence that the effect of beta-delayed fission appears to be seriously overestimated in uranium decay chains with A = 252 to 257. With this conclusion, it follows that this estimate of the galactic age must be considered more uncertain than if the calculated rates of beta-delayed fission were found to be acceptable. The nuclear level structure of 238Np has been investigated using the 237Np(n,..gamma..)238Np reaction and the alpha decay of 242mAm as experimental probes. Having established a level scheme for 238Np that includes 47 excited levels and 93 secondary transitions, we find a high degree of correspondence between the experimental band structure and that of a semi-empirical model developed to predict excitations in odd-odd deformed nuclei. 35 refs., 4 figs., 3 tabs.
Date: February 19, 1988
Creator: Hoff, R.W.
System: The UNT Digital Library
Beryllium Science: US-UK agreement on the use of Atomic Energy for mutual defense (open access)

Beryllium Science: US-UK agreement on the use of Atomic Energy for mutual defense

Twenty-seven papers are presented on beryllium supply, production, fabrication, safe handling, analysis, powder technology, and coatings. Separate abstracts have been prepared for the individual papers. (DLC)
Date: February 19, 1988
Creator: Hanafee, J.E. (ed.)
System: The UNT Digital Library
Inertial fusion power for space applications (open access)

Inertial fusion power for space applications

More than thirty-seven design concepts have been proposed for terrestrial ICF power plants. The design space is large because of the many allowable driver and reaction chamber combinations. These design studies have illustrated advantages of ICF power plants over other sources in lower impact on the environment, high safety, and almost no dependence on consumables like fuel. The fact that, once built, a 1000 MW/sub e/ ICF power plant would require only 240 kg of deuterium and from 770 to 9260 kg of lithium to run for five years (at 70% capacity factor) makes it potentially attractive for space power also. However, the designs proposed to date have emphasized features that would make the plant attractive for terrestrial applications, where economics, efficiency, and environmental considerations dominate. The resulting plants are large and contain many very heavy components that would not be at attractive for space applications. In this paper, we evaluate alternative ICF driver and reactor technologies using space application criteria and also discuss how some of those technologies can be altered to produce smaller, lighter fusion power sources for space.
Date: May 19, 1986
Creator: Meier, W. R.; Hogan, W. J.; Hoffman, N. J.; Murray, K. A. & Olson, R. E.
System: The UNT Digital Library
Correlation between predicted and observed levels of airborne tritium at Lawrence Livermore Laboratory site boundary (open access)

Correlation between predicted and observed levels of airborne tritium at Lawrence Livermore Laboratory site boundary

At the Lawrence Livermore Laboratory, a computer code based on the Gaussian plume model is used to estimate radiation doses from routine or accidental release of airborne radioactive material. Routine releases of tritium have been used as a test of the overall uncertainty associated with these estimates. The ration of concentration to release rate at distances from the two principal release points to each of six site boundary sampling locations has been calcuated using local meteorological data. The concentration of airborne tritiated water vapor is continuously measured at the six sampling stations as part of the Laboratory's environmental monitoring program. Comparison of predicted with observed annual tritiated water concentrations in 1978 showed an average ratio of 2.6 with a range of from 0.97 to 5.8.
Date: February 19, 1980
Creator: Lindeken, C. L.; Silver, W. J.; Toy, A. J. & White, J. H.
System: The UNT Digital Library
Determination of first-order machine parameters from particle physics requirements. Group 1. Summary report. Primary parametric relationships. I (open access)

Determination of first-order machine parameters from particle physics requirements. Group 1. Summary report. Primary parametric relationships. I

High luminosity will be necessary for the study of many of the new phenomena expected in the SSC energy region. Particle detectors, however, are limited in the number of simultaneous interactions which they can handle, and thus need a good duty cycle with collisions spread out in time to the greatest extent possible. To avoid the larger number of stored protons required for continuous beams, we have considered bunched beams of protons crossing at a small angle. Plots are given of the dependence on bunch separation of the emittance, number of protons, etc., needed for 10/sup 33/ cm/sup -2/ sec/sup -1/. In order to minimize the number of stored protons (approx. 10/sup 14//ring), an emittance roughly ten times smaller than that presently achieved at high energies is required for a bunch separation of 6 meters (20 nsec).
Date: January 19, 1984
Creator: Diebold, R.
System: The UNT Digital Library
Status of the Lawrence Berkeley Laboratory and Lawrence Livermore National Laboratory free electron laser (FEL) (open access)

Status of the Lawrence Berkeley Laboratory and Lawrence Livermore National Laboratory free electron laser (FEL)

A description of the FEL experiment underway at the 10 kA, 5 MeV Experimental Test Accelerator (ETA) is described. The facility has been designed to investigate the high-gain operation of an FEL.
Date: September 19, 1983
Creator: Orzechowski, T.J.; Moebus, M.C.; Penko, F.A.; Prosnitz, D.; Rogers, D.; Chavis, C.S. et al.
System: The UNT Digital Library
Proceedings of the twenty-third WANTO meeting: a workshop to discuss policies and practices used to assure quality NDE operations (open access)

Proceedings of the twenty-third WANTO meeting: a workshop to discuss policies and practices used to assure quality NDE operations

Ten papers were presented at the meeting. A separate abstract was prepared for each paper. (LCL)
Date: November 19, 1981
Creator: Baxter, G.R. (comp.)
System: The UNT Digital Library
Sodium pool fire model for CONACS code. [LMFBR] (open access)

Sodium pool fire model for CONACS code. [LMFBR]

The modeling of sodium pool fires constitutes an important ingredient in conducting LMFBR accident analysis. Such modeling capability has recently come under scrutiny at Westinghouse Hanford Company (WHC) within the context of developing CONACS, the Containment Analysis Code System. One of the efforts in the CONACS program is to model various combustion processes anticipated to occur during postulated accident paths. This effort includes the selection or modification of an existing model and development of a new model if it clearly contributes to the program purpose. As part of this effort, a new sodium pool fire model has been developed that is directed at removing some of the deficiencies in the existing models, such as SOFIRE-II and FEUNA.
Date: October 19, 1982
Creator: Yung, S.C.
System: The UNT Digital Library
Toward a permanent lunar settlement in the coming decade: the Columbus Project (open access)

Toward a permanent lunar settlement in the coming decade: the Columbus Project

The motivation for creating a permanent lunar settlement is sketched, and reasons for doing so in the coming decade are put forward. A basic plan to accomplish this is outlined, along technical and programmatic axes. It is concluded that founding a lunar settlement on the five hundredth anniversary of the Columbus landing - a Columbus Project - could be executed as a volunteer-intensive American enterprise requiring roughly six thousand man-years of skilled endeavor and a total Governmental contribution of the order of a half-billion dollars. 8 figs.
Date: November 19, 1985
Creator: Hyde, R. A.; Ishikawa, M. Y. & Wood, L. L.
System: The UNT Digital Library
Study of proton-induced reactions and correlation with fast-neutron scattering (open access)

Study of proton-induced reactions and correlation with fast-neutron scattering

The generation of cross sections for fast neutron-nucleon interactions obtained from elastic and charge-exchange proton data is discussed in terms of the Lane model formalism. A general description of the interaction of nucleons with nuclei is presented in terms of the optical model and the extended (or coupled-channel) optical model, together with the relation of these models to microscopic calculations of the nucleon-nucleon interaction. Comparisons between neutron elastic data and calculations carried out with optical model potentials obtained from (p,p) and (p,n) data are presented for a large number of nuclei. The validity of the Lane model and the importance of coupled effects in the actinide region are shown in a detailed comparison of calculations for elastic and inelastic neutron differential cross sections and measurements for /sup 232/Th and /sup 238/U.
Date: January 19, 1982
Creator: Hansen, L. F.
System: The UNT Digital Library
Simple, compact, high brightness source for x-ray lithography and x-ray radiography (open access)

Simple, compact, high brightness source for x-ray lithography and x-ray radiography

A simple, compact, high brightness x-ray source has recently been built. This source utilizes a commercially available, cylindrical geometry electron beam evaporator, which has been modified to enhance the thermal cooling to the anode. Cooling is accomplished by using standard, low-conductivity laboratory water, with an inlet pressure of less than 50 psi, and a flow rate of approx.0.3 gal/min. The anode is an inverted cone geometry for efficient cooling. The x-ray source has a measured sub-millimeter spot size (FWHM). The anode has been operated at 1 KW e-beam power (10 KV, 100 ma). Higher operating levels will be investigated. A variety of different x-ray lines can be obtained by the simple interchange of anodes of different materials. Typical anodes are made from easily machined metals, or materials which are vacuum deposited onto a copper anode. Typically, a few microns of material is sufficient to stop 10 KV electrons without significantly decreasing the thermal conductivity through the anode. The small size and high brightness of this source make it useful for step and repeat exposures over several square centimeter areas, especially in a research laboratory environment. For an aluminum anode, the estimated Al-K x-ray flux at 10 cms from the source …
Date: February 19, 1986
Creator: Hawryluk, A.M.
System: The UNT Digital Library
Quantum mechanical stabilization of Minkowski signature wormholes (open access)

Quantum mechanical stabilization of Minkowski signature wormholes

When one attempts to construct classical wormholes in Minkowski signature Lorentzian spacetimes violations of both the weak energy hypothesis and averaged weak energy hypothesis are encountered. Since the weak energy hypothesis is experimentally known to be violated quantum mechanically, this suggests that a quantum mechanical analysis of Minkowski signature wormholes is in order. In this note I perform a minisuperspace analysis of a simple class of Minkowski signature wormholes. By solving the Wheeler-de Witt equation for pure Einstein gravity on this minisuperspace the quantum mechanical wave function of the wormhole is obtained in closed form. The wormhole is shown to be quantum mechanically stabilized with an average radius of order the Planck length. 8 refs.
Date: May 19, 1989
Creator: Visser, M.
System: The UNT Digital Library
Safety procedures for the MFTF sustaining-neutral-beam power supply (open access)

Safety procedures for the MFTF sustaining-neutral-beam power supply

The MFTF SNBPSS comprises a number of sources of potentially hazardous electrical energy in a small physical area. Power is handled at 80 kV dc, 80 A; 70 V dc, 4000 A; 25 V dc, 5500 A; 3 kV dc, 10 A; and 2 kV dc, 10 A. Power for these systems is furnished from two separate 480 V distribution systems and a 13.8 kV distribution system. A defense in depth approach is used; interlocks are provided in the hardware to make it difficult to gain access to an energized circuit, and the operating procedure includes precautions which would protect personnel even if no interlocks were working. The complexity of the system implies a complex operating procedure, and this potential complexity is controlled by presenting the procedure in a modular form using 37 separate checklists for specific operations. The checklists are presented in flowchart form, so contingencies can be handled at the lowest possible level without compromising safety.
Date: October 19, 1981
Creator: Wilson, J. H.
System: The UNT Digital Library
Constraints on the atmospheres of Type I supernovae (open access)

Constraints on the atmospheres of Type I supernovae

The Ca II absorption lines observed in the late time optical spectra of Type I supernovae are analyzed in the context of the /sup 56/Ni model. The analysis indicates that a metal rich atmosphere of mass approx. 0.2 M/sub solar mass/ surrounds the /sup 56/Ni core. This result is consistent with properties of the atmosphere derived from spectra near maximum light.
Date: October 19, 1981
Creator: Axelrod, T.S.
System: The UNT Digital Library
High-speed LWR transients simulation for optimizing emergency response (open access)

High-speed LWR transients simulation for optimizing emergency response

The purpose of computer-assisted emergency response in nuclear power plants, and the requirements for achieving such a response, are presented. An important requirement is the attainment of realistic high-speed plant simulations at the reactor site. Currently pursued development programs for plant simulations are reviewed. Five modeling principles are established and a criterion is presented for selecting numerical procedures and efficient computer hardware to achieve high-speed simulations. A newly developed technology for high-speed power plant simulation is described and results are presented. It is shown that simulation speeds ten times greater than real-time process-speeds are possible, and that plant instrumentation can be made part of the computational loop in a small, on-site minicomputer. Additional technical issues are presented which must still be resolved before the newly developed technology can be implemented in a nuclear power plant.
Date: November 19, 1984
Creator: Wulff, W.; Cheng, H.S.; Lekach, S.V.; Mallen, A.N. & Stritar, A.
System: The UNT Digital Library
Reactivity feedback from irradiated pin failure in unprotected slow TOP accidents in LMFBR's (open access)

Reactivity feedback from irradiated pin failure in unprotected slow TOP accidents in LMFBR's

The present work is an outgrowth of studies made in support of CRBR licensing, but the conclusions drawn should be generally applicable to oxide-fueled LMFBR's. The accident under consideration is a 10 cents/s unprotected TOP (transient overpower), for which a series of PLUTO2/SAS4A calculations has been performed using a higher power CRBR EOC3 fuel pin which had 275 days irradiation. The assumption was made in the licensing work that a short pin failure will occur at the axial midplane, maximizing the positive fuel motion reactivity effect, as it was felt that a less conservative assumption could not be conclusively justified. This assumption is also made in the present case.
Date: September 19, 1984
Creator: Hummel, H.H. & Pizzica, P.A.
System: The UNT Digital Library
Statistical vs valence neutron neutron capture in /sup 98/Mo (open access)

Statistical vs valence neutron neutron capture in /sup 98/Mo

It has often been reported that, in mass regions corresponding to peaks in the neutron strength function, nonstatistical mechanisms contribute a significant or even major portion of the average radiation width in the beginning of the resonance region. This could severely limit the possibility of calculating caputure cross sections for targets where experimental data are lacking, because such direct effects are sensitive to the detailed nuclear level structure in the daughter nucleus. The reaction /sup 98/Mo+n was examined for neutrons in the 1 keV to 3 MeV energy range, because this case is often cited as one of the clearest examples of valence neutron capture effects. Preliminary calculations are presented which suggest that these nonstatistical effects rapidly disappear when measurements from even a small number of resonances are averaged.
Date: June 19, 1981
Creator: Gardner, D. G.
System: The UNT Digital Library
Microwave kinoform for magnetic fusion (open access)

Microwave kinoform for magnetic fusion

A microwave kinoform that modifies both the phase and polarization of an incident wavefront has been designed. This kinoform for the TMX-U magnetic fusion experiment has been fabricated and tested. The design procedure, method of fabrication, and experimental test results are discussed.
Date: July 19, 1983
Creator: Gallagher, N.C. Jr. & Sweeney, D.W.
System: The UNT Digital Library
Transcript of the workshop to discuss plans for a National High Intensity Radioactive Nuclear Beam Facility (open access)

Transcript of the workshop to discuss plans for a National High Intensity Radioactive Nuclear Beam Facility

Following the First International Conference on Radioactive Nuclear Beams'' in Berkeley, a workshop was held on October 19, 1989 at the Lawrence Berkeley Laboratory to discuss plans for a National High Intensity Radioactive Nuclear Beam (RNB) Facility. The purpose of the workshop was -- after having discussed during the conference the physics question that can be addressed with RNBs -- to evaluate more concretely the possibilities for actually constructing such a facility in this country. It is becoming increasingly apparent that facility producing beams of radioactive nuclei with extreme neutron-to-proton ratios is of high scientific interest and technically feasible. It would allow the study of nuclear structure and astrophysical reactions very far from the line of stable nuclei, and could provide new possibilities of reaching the long-sought island of stability of superheavy nuclei. Such facilities are under advanced consideration in Japan and at CERN in Europe. This paper contains a slightly edited transcript of the tape recording that was made of the workshop.
Date: October 19, 1989
Creator: Nitschke, J.M. (ed.)
System: The UNT Digital Library