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Mirror fusion. Quarterly report, April-June 1981
The information in each Quarterly is presented in the same sequence as in the Field Work Package Proposal and Authorization System (WPAS) submissions prepared for the U.S. Department of Energy; the main sections are Applied Plasma Physics, Confinement Systems, Development and Technology, and Mirror Fusion Test Facility (Planning and Projects). On occasion, we shall include information pertaining to the LLNL role as Lead Laboratory for the Open Systems Mirror Fusion Program. Each of these sections is introduced by an overall statement of the goals and purposes of the groups reporting in it. As appropriate within each section, statements of the goals of individual programs and projects are followed by articles containing summaries of significant recent activity and descriptive text.
Date:
September 11, 1981
Creator:
unknown
System:
The UNT Digital Library
A PULSED EDDY CURRENT TEST SYSTEM USING REFLECTED FIELDS
An eddy current test system is described in which the test information is detected as a series of fields reflected from the metal surface and interior. Pulsed electromagnetic fields are caused to impinge upon the test specimen. These fields are restricted to a small cross sectional area over a path in space long enough to be useful for test purposes by devices called mask-apenture assemblies. This approach provides a number of advantages over conventional eddy current methods of comparable capabilities, including superior surface resolution, a reduction in circuit complexity, and an improvement in stability and reliability. Various applications and test results are discussed. (auth)
Date:
June 11, 1962
Creator:
Renken, C. J.
System:
The UNT Digital Library
Application of automated deduction to the search for single axioms for exponent groups
We present new results in axiomatic group theory obtained by using automated deduction programs. The results include single axioms, some with the identity and others without, for groups of exponents 3, 4, 5 and 7, and a general form for single axioms for groups of odd exponent. The results were obtained by using the programs in three separate ways: as a symbolic calculator, to search for proofs,and to search for couterexamples. We also touch on relations between logic programming and automated reasoning.
Date:
February 11, 1992
Creator:
McCune, W. & Wos, L.
System:
The UNT Digital Library
Thyratron characteristics under high di/dt and high-repetition-rate operation
Power conditioning systems for high peak and average power, high repetition rate discharge excited lasers involve operation of modulator components in unconventional regimes. Reliable operation of switches and energy storage elements under high voltage and high di/dt conditions is a pacing item for laser development at the present time. To test and evaluate these components a Modulator Component Test Facility (MCTF) was constructed. The MCTF consists of a command charge system, energy storage capacitors, thyratron switch with inverse thyratron protection, and a resistive load. The modulator has initially been operated at voltages up to 60 kV at 600 Hz. Voltage, current, and calorimetric diagnostics are provided for major modulator components. Measurements of thyratron characteristics under high di/dt operation are presented. Commutation energy loss and di/dt have been measured as functions of the tube hydrogen pressure.
Date:
May 11, 1981
Creator:
Ball, D.; Hill, J. & Kan, T.
System:
The UNT Digital Library
Symplectic numerical integration of Hamiltonian systems
This paper describes some general techniques available for symplectic or Lie-Poisson integration and illustrate the results with some numerical computations. In this spirit, I also discuss reversible integration, equivariant integration, integration of volume preserving flows, and symplectic cellular automata. My intention is not to be exhaustive but to give a representative review. 76 refs., 5 figs.
Date:
September 11, 1989
Creator:
Scovel, C.
System:
The UNT Digital Library
Heating by the Raman instability
Computer simulations are presented of the reflection and heating due to stimulated Raman backscatter of intense laser light in large regions of underdense plasma. The heated electron distribution is found to be approximately a Maxwellian of temperature (m/sub e//2)v/sub p//sup 2/, where v/sub p/ is the phase velocity of the electron plasma wave. A simple model of the reflection is presented. Raman may cause a pre-heat problem with large laser fusion reactor targets.
Date:
April 11, 1980
Creator:
Estabrook, K.G. & Kruer, W.L.
System:
The UNT Digital Library
Laser-damage thresholds of thin-film optical coatings at 248 nm
We have measured the laser-induced damage thresholds for 248 nm wavelength light of over 100 optical coatings from commercial vendors and research institutions. All samples were irradiated once per damage site with temporally multi-lobed, 20-ns pulses generated by a KrF laser. The survey included high, partial, and dichroic reflectors, anti-reflective coatings, and single layer films. The samples were supplied by ten vendors. The majority of samples tested were high reflectors and antireflective coatings. The highest damage thresholds were 8.5 to 9.4 J/cm/sup 2/, respectively. Although these represent extremes of what has been tested so far, several vendors have produced coatings of both types with thresholds which consistently exceed 6 J/cm/sup 2/. Repeated irradiations of some sites were made on a few samples. These yielded no degradation in threshold, but in fact some improvement in damage resistance. These same samples also exhibited no change in threshold after being retested seven months later.
Date:
December 11, 1981
Creator:
Milam, D.; Rainer, F. & Lowdermilk, W.H.
System:
The UNT Digital Library
Low-exposure tritium radiotoxicity in mammals
Studies of tritium radiotoxicity involving chronic /sup 3/H0H exposures in mammals demonstrate in both mice and monkeys that biological effects can be measured following remarkably low levels of exposure - levels in the range of serious practical interest to radiation protection. These studies demonstrate also that deleterious effects of /sup 3/H beta radiation do not differ significantly from those of gamma radiation at high exposures. In contrast, however, at low exposures tritium is significantly more effective than gamma rays, rad for rad, by a factor approaching 3. This is important for hazard evaluation and radiation protection because knowledge concerning biological effects of chronic low-level radiation exposure has come mainly from gamma-ray data; and predictions based on gamma-ray data will underestimate tritium effects - especially at low exposures - unless the RBE is fully taken into account.
Date:
February 11, 1982
Creator:
Dobson, R.L.
System:
The UNT Digital Library
Dipole aperture and superconductor requirements
The cost of an accelerator is not proportional to the aperture. A change in aperture by a certain percentage results in an overall accelerator cost change by only a fraction of that percentage; the fraction may be between 0.1 and 0.5 and is almost independent of the bending field. This estimate is obtained by analyzing the superconductor requirements as a function of aperture and by making rough estimates of the largest cost items of the accelerator such as magnets and ring tunnel.
Date:
December 11, 1983
Creator:
Wipf, S.L.
System:
The UNT Digital Library
Writing Parallel, Discrete-Event Simulations in Modsim: Insight and Experience
The Time Warp Operating System (TWOS) has been the focus of much research in parallel simulation. A new language, called ModSim, has been developed for use in conjunction with TWOS. The coupling of ModSim and TWOS provides a tool to construct large, complex simulation models that will run on several parallel and distributed computer systems. As part of the Griffin Project'' underway here at Los Alamos National Laboratory, there is strong interest in assessing the coupling of ModSim and TWOS from an application-oriented perspective. To this end, a key component of the Eagle combat simulation has been implemented in ModSim for execution on TWOS. In this paper brief overviews of ModSim and TWOS will be presented. Finally, the compatibility of the computational models presented by the language and the operating system will be examined in light of experience gained to date. 18 refs., 4 figs.
Date:
September 11, 1989
Creator:
Rich, D.O. & Michelsen, R.E.
System:
The UNT Digital Library
Underground muon observations in the Soudan 2 detector
The Soudan 2 nucleon decay detector has recorded data since Summer 1988 using a quarter (dimensions 4 m by 8 m by 5 m high) of the eventual detector. This iron-argon time projection chamber records extensive data on each event and has excellent angular and multi-track resolution. We describe the trigger, the event analysis procedure and the current status of the detector and the underground muon data sample. 1 ref.
Date:
September 11, 1989
Creator:
Allison, W. W. M.; Barr, G. D.; Brooks, C. B.; Cobb, J. H.; Kirby-Gallagher, L. M.; Giles, R. H. et al.
System:
The UNT Digital Library
Mechanical model for ductility loss
A mechanical model was constructed to probe into the mechanism of ductility loss. Fracture criterion based on critical localized deformation was undertaken. Two microstructure variables were considered in the model. Namely, the strength ratio of grain boundary affected area to the matrix, ..cap omega.., and the linear fraction, x, of grain boundary affected area. A parametrical study was carried out. The study shows that the ductility is very sensitive to those microstructure parameters. The functional dependence of ductility to temperature as well as strain-rate, suggested by the model, is demonstrated to be consistent with the observation.
Date:
February 11, 1980
Creator:
Hu, W.L.
System:
The UNT Digital Library
Underground muons from the direction of Cygnus X-3
We report on 3.2 years live time of underground muon observations taken between 1981 and 1989 using the Soudan 1 proportional tube detector, located at a depth of 1800 m water equivalent. The post-1984 observations are consistent with our earlier data on an excess signal apparently correlated with the Cygnus X-3 orbital period. The signal-to-background ratio in the entire data sample is 1 to 3 percent, depending on phase width. 10 refs., 2 figs., 1 tab.
Date:
September 11, 1989
Creator:
Johns, K.; Marshak, M. L.; Peterson, E. A.; Ruddick, K.; Shupe, M.; Ayres, D. S. et al.
System:
The UNT Digital Library
Energy planning and management in developing countries: thoughts concerning a conceptual framework
The unique characteristics of the energy situation in developing countries imposes a unique set of requirements on analytical techniques used for energy planning. The urgency of the situation requires the rapid development and use of simplified models which make maximum use of available data but which can reflect the international energy context. Those techniques must also be able to deal with central energy/development issues such as energy equity or the energy implication of social equity policies, centralized vs. decentralized development, and urbanization.
Date:
October 11, 1977
Creator:
Nathans, R. & Palmedo, P.F.
System:
The UNT Digital Library
Reaction rate calculations via transmission coefficients
The transmission coefficient of a wavepacket traversing a potential barrier can be determined by steady state calculations carried out in imaginary time instead of by real time dynamical calculations. The general argument is verified for the Eckart barrier potential by a comparison of transmission coefficients calculated from real and imaginary time solutions of the Schroedinger equation. The correspondence demonstrated here allows a formulation for the reaction rate that avoids difficulties due to both rare events and explicitly time dependent calculations. 5 refs., 2 figs.
Date:
July 11, 1985
Creator:
Feit, M. D. & Alder, B. J.
System:
The UNT Digital Library
Bacterial Communities of the Coronal Sulcus and Distal Urethra of Adolescent Males
Article on bacterial communities of the coronal sulcus and distal urethra of adolescent males.
Date:
May 11, 2012
Creator:
Nelson, David E.; Dong, Qunfeng; Van Der Pol, Barbara; Toh, Evelyn; Fan, Baochang; Katz, Barry P. et al.
System:
The UNT Digital Library
Texas Program Gives Gifted Math and Science Students Chance to Finish School and Start College Simulataneously
Article about the Texas Academy of Mathematics and Science, its students, the requirements, and the regulations.
Date:
October 11, 1989
Creator:
Mangan, Katherine S.
System:
The UNT Digital Library
EPROM-based LSI-11 for distributed instrumentation control
The LLNL Nuclear Chemistry Counting Facility (NCCF) is being converted to a modern production facility. A computer network has been designed and built to implement this conversion. The outermost node of the computer network is a dedicated EPROM-based controller. The controller handles the details of driving the attached nuclear instrumentation, providing a standard interface to the remainder of the network. This paper addresses the design and the implementation of the dedicated instrumentation controller.
Date:
November 11, 1981
Creator:
Hunt, D.N.
System:
The UNT Digital Library
Stability and disturbance of large dc superconducting magnets
This paper addresses the stability aspects of several successful dc superconducting magnets such as large bubble chamber magnets, and magnets for the Mirror Fusion Test Facility and MHD Research Facility. Specifically, it will cover Argonne National Laboratory 12-Foot Bubble Chamber magnets, the 15-foot Bubble Chamber magnets at Fermi National Laboratory, the MFTF-B Magnet System at Lawrence Livermore National Laboratory, the U-25B Bypass MHD Magnet, and the CFFF Superconducting MHD magnet built by Argonne National Laboratory. All of these magnets are cooled in pool-boiling mode. Magnet design is briefly reviewed. Discussed in detail are the adopted stability critera, analyses of stability and disturbance, stability simulation, and the final results of magnet performance and the observed coil disturbances.
Date:
November 11, 1981
Creator:
Wang, S. T.
System:
The UNT Digital Library
Cytometry of mammalian sperm
Male germ cells respond dramatically to a variety of insults and are important reproductive dosimeters. Semen analyses are very useful in studies on the effects of drugs, chemicals, and environmental hazards on testicular function, male fertility and heritable germinal mutations. The accessibility of male cells makes them well suited for analytical cytology. We might automate the process of determining sperm morphology but should not do so solely for increased speed. Rather, richer tangible benefits will derive from cytometric evaluation through increased sensitivity, reduced subjectivity, standardization between investigators and laboratories, enhanced archival systems, and the benefits of easily exchanged standardized data. Inroads on the standardization of assays for motility and functional integrity are being made. Flow cytometric analysis of total DNA content of individual sperm is an insensitive means to detect exposure to reproductive toxins because of the small size and low frequency of the DNA content errors. Flow cytometry can be applied to determine the proportions of X- and Y-sperm in semen samples.
Date:
October 11, 1983
Creator:
Gledhill, B.L.
System:
The UNT Digital Library
Fusion devices
Three types of thermonuclear fusion devices currently under development are reviewed for an electric utilities management audience. Overall design features of laser fusion, tokamak, and magnetic mirror type reactors are described and illustrated. Thrusts and trends in current research on these devices that promise to improve performance are briefly reviewed. Twenty photographs and drawings are included. (RME)
Date:
October 11, 1977
Creator:
Fowler, T.K.
System:
The UNT Digital Library
Insulator materials in high power lasers for inertial fusion: present and future
A summary is given of the important characteristics of currently used insulator materials. Figures of merit for materials needed in future systems are identified. A methodology for identifying and evaluating new materials meeting the stringent performance requirements of future fusion laser systems is outlined.
Date:
November 11, 1983
Creator:
Krupke, W. F.
System:
The UNT Digital Library
Energy-beam processing studies on Ta/U and Ir/Ta systems. [Laser-and electron-beam melting]
Films of Ta metal on uranium and of Ir metal on tantalum have been irradiated and melted by pulses from Q-switched Ruby and frequency-doubled Nd:YAG lasers to investigate the nature of the resulting mixtures in light of the very different binary-phase diagrams of the two systems. In addition, a two-phase Ir-Ta alloy has been surface-processed with CW CO/sub 2/-laser radiation and with an electron beam in order to study microstructure refinement and test the advantage of using alloys as opposed to film-on-substrate combinations for the development of claddings.
Date:
November 11, 1983
Creator:
Kaufmann, E. N.; Peercy, P. S.; Jacobson, D. C.; Draper, C. W.; Huegel, F. J.; Echer, C. J. et al.
System:
The UNT Digital Library
Framework for Analyzing Safeguards Alarms and Response Decisions
This paper describes a quantitative approach to help evaluate and respond to safeguards alarms. These alrms may be generated internally by a facility's safeguards systems or externally by individuals claiming to possess stolen Special Nuclear Material (SNM). This approach can be used to identify the most likely cause of an alarm - theft, hoax, or error - and to evaluate alternative responses to alarms. Possible responses include conducting investigations, initiating measures to recover stolen SNM, and replying to external threats. Based on the results of each alarm investigation step, the evaluation revises the likelihoods of possible causes of an alarm, and uses this information to determine the optimal sequence of further responses. The choice of an optimal sequence of responses takes into consideration the costs and benefits of successful thefts or hoaxes. These results provide an analytical basis for setting priorities and developing contingency plans for responding to safeguards alarms.
Date:
June 11, 1982
Creator:
Al-Ayat, R. A.; Judd, B. R. & McCord, R. K.
System:
The UNT Digital Library