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Mirror fusion. Quarterly report, April-June 1981 (open access)

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
Thyratron characteristics under high di/dt and high-repetition-rate operation (open access)

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
Laser-damage thresholds of thin-film optical coatings at 248 nm (open access)

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
EPROM-based LSI-11 for distributed instrumentation control (open access)

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 (open access)

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
Mirror Fusion Test Facility magnet system (open access)

Mirror Fusion Test Facility magnet system

In 1979, R.H. Bulmer of Lawrence Livermore National Laboratory (LLNL) discussed a proposed tandem-mirror magnet system for the Mirror Fusion Test Facility (MFTF) at the 8th symposium on Engineering Problems in Fusion Research. Since then, Congress has voted funds for expanding LLNL's MFTF to a tandem-mirror facility (designated MFTF-B). The new facility, scheduled for completion by 1985, will seek to achieve two goals: (1) Energy break-even capability (Q or the ratio of fusion energy to plasma heating energy = 1) of mirror fusion, (2) Engineering feasibility of reactor-scale machines. Briefly stated, 22 superconducting magnets contained in a 11-m-diam by 65-m-long vacuum vessel will confine a fusion plasma fueled by 80 axial streaming-plasma guns and over 40 radial neutral beams. We have already completed a preliminary design of this magnet system.
Date: September 11, 1981
Creator: VanSant, J. H.; Kozman, T. A.; Bulmer, R. H. & Ng, D. S.
System: The UNT Digital Library
Nova Event Logging System (open access)

Nova Event Logging System

Nova is a 200 terawatt, 10-beam High Energy Glass Laser currently under construction at LLNL. This facility, designed to demonstrate the feasibility of laser driven inertial confinement fusion, contains over 5000 elements requiring coordinated control, data acquisition, and analysis functions. The large amounts of data that will be generated must be maintained over the life of the facility. Often the most useful but inaccessible data is that related to time dependent events associated with, for example, operator actions or experiment activity. We have developed an Event Logging System to synchronously record, maintain, and analyze, in part, this data. We see the system as being particularly useful to the physics and engineering staffs of medium and large facilities in that it is entirely separate from experimental apparatus and control devices. The design criteria, implementation, use, and benefits of such a system will be discussed.
Date: May 11, 1981
Creator: Calliger, R.J. & Suski, G.J.
System: The UNT Digital Library
Progress toward fusion energy (open access)

Progress toward fusion energy

This paper summarizes the basis for the present optimism in the magnetic fusion program, and describes some of the remaining tasks leading to a demonstration power reactor and the primary technologies necessary for that endeavor.
Date: March 11, 1981
Creator: Thomassen, K.I.
System: The UNT Digital Library
Utilizing subcooled, superfluid He-II in the design of a 12-tesla tandem-mirror experiment (open access)

Utilizing subcooled, superfluid He-II in the design of a 12-tesla tandem-mirror experiment

A design study of 12-T yin-yang coils for a conceptual Tandem Mirror Next Step (TMNS) facility has been recently performed by Lawrence Livermore National Laboratory in conjunction with the Convair Division of General Dynamics. The large magnets have major and minor radii of 3.7 and 1.5 m, 0.70 x 3.75 m/sup 2/ cross section, 46.3 MA turns, and an overall current density of 1765 A/cm/sup 2/, obtained by the use of Nb/sub 3/Sn and Nb-Ti superconductors. Each coil is composed of several subcoils separated by internal strengthening substructure to react the enormous electromagnetic forces. The size of the yin-yang coils, and hence the current density, was reduced by utilizing subcooled, superfluid He-II at 1.8 K for the coolant. This paper reviews the design study, with emphasis on He-II heat transport and conductor stability. Methods are also presented which allow the extension of Gorter-Mellink-channel calculations to encompass multiple, interconnecting coolant channels.
Date: November 11, 1981
Creator: Hoard, R. W.; Cornish, D. N.; Baldi, R. W. & Taylor, W. D.
System: The UNT Digital Library
Moving to a total VM environment (open access)

Moving to a total VM environment

The Stanford Linear Accelerator Center is a single purpose laboratory operated by Stanford University for the Department of Energy. Its mission is to do research in High Energy (particle) physics. This research involves the use of large and complex electronic detectors. Each of these detectors is a multi-million dollar device. A part of each detector is a computer for process control and data logging. Most detectors at SLAC now use VAX 11/780s for this purpose. Most detectors record digital data via this process control computer. Consequently, physics today is not bounded by the cost of analog to digital conversion as it was in the past, and the physicist is able to run larger experiments than were feasible a decade ago. Today a medium sized experiment will produce several hundred full reels of 6250 BPI tape whereas a large experiment is a couple of thousand reels. The raw data must first be transformed into physics events using data transformation programs. The physicists then use subsets of the data to understand what went on. The subset may be anywhere from a few megabytes to 5 or 6 gigabytes of data (30 or 40 full reels of tape). This searching would be best …
Date: August 11, 1981
Creator: Johnston, T.Y.
System: The UNT Digital Library
Summary of U.S. Compact Torus Experiments (open access)

Summary of U.S. Compact Torus Experiments

During the past several years a rapid increase has occurred in compact torus (CT) research in the United States, reflecting renewed interest in this simplified reactor consequences of this configuration. This paper reviews early approaches to CT formation and results and summarizes present experimental studies. Recent experiments have demonstrated a number of macroscopic aspects of the CT, including the conditions under which a macroscopically stable CT can be formed and maintained. Scaling experiments and more detailed studies of plasma transport in progress are discussed along with experiments under construction.
Date: March 11, 1981
Creator: Hartman, Charles W.
System: The UNT Digital Library
Flywheel rotor and containment technology development (open access)

Flywheel rotor and containment technology development

The goals of the project are: to develop an economical and practical composite flywheel having an energy density of 88 Wh/kg at failure, an operational energy density of 44 to 55 Wh/kg, and an energy storage capacity of approximately 1 kWh; to determine the suitability of various manufacturing processes for low-cost rotor fabrication; to investigate flywheel and flywheel-systems dynamics; to test and evaluate prototype rotors for use in transportation and stationary applications; and to develop a fail-safe, lightweight, and low-cost flywheel containment. The following tasks have been accomplished: evaluation and selection of 1-kWh, first-generation, advanced flywheel rotor designs for subsequent development towards the DOE-established energy density goal of 88 Wh/kg at burst; completion of an advanced design concept for a flywheel primary containment structure, capable of containing the failure of a 1-kWh flywheel rotor and targeted for vehicular applications; non-destructive inspection and burst testing of approximately twenty (20) prototype rotors, and initiation of cyclic testing; completion of various activities in the areas of rotor manufacturing processes, dynamic analyses and composite materials design data generation; and initiation of an economic feasibility study to establish a rational costing methodology for composite rotors and containment.
Date: August 11, 1981
Creator: Kulkarni, S.V.
System: The UNT Digital Library
Plating on stainless steel alloys (open access)

Plating on stainless steel alloys

Quantitative adhesion data are presented for a variety of electroplated stainless steel type alloys. Results show that excellent adhesion can be obtained by using a Wood's nickel strike or a sulfamate nickel strike prior to final plating. Specimens plated after Wood's nickel striking failed in the deposit rather than at the interface between the substrate and the coating. Flyer plate quantitative tests showed that use of anodic treatment in sulfuric acid prior to Wood's nickel striking even further improved adhesion. In contrast activation of stainless steels by immersion or cathodic treatment in hydrochloric acid resulted in very reduced bond strengths with failure always occurring at the interface between the coating and substrate.
Date: September 11, 1981
Creator: Dini, J. W. & Johnson, H. R.
System: The UNT Digital Library
Clinch River Breeder Reactor Plant Steam Generator Few Tube Test model post-test examination (open access)

Clinch River Breeder Reactor Plant Steam Generator Few Tube Test model post-test examination

The Steam Generator Few Tube Test (FTT) was part of an extensive testing program carried out in support of the Clinch River Breeder Reactor Plant (CRBRP) steam generator design. The testing of full-length seven-tube evaporator and three-tube superheater models of the CRBRP design was conducted to provide steady-state thermal/hydraulic performance data to full power per tube and to verify the absence of multi-year endurance problems. This paper describes the problems encountered with the mechanical features of the FTT model design which led to premature test termination, and the results of the post-test examination. Conditions of tube bowing and significant tube and tube support gouging was observed. An interpretation of the visual and metallurgical observations is also presented. The CRBRP steam generator has undergone design evaluations to resolve observed deficiences found in the FFTM.
Date: March 11, 1981
Creator: Impellezzeri, J. R.; Camaret, T. L. & Friske, W. H.
System: The UNT Digital Library
Analytic model of the radiation-dominated decay of a compact toroid (open access)

Analytic model of the radiation-dominated decay of a compact toroid

The coaxial-gun, compact-torus experiments at LLNL and LASNL are believed to be radiation-dominated, in the sense that most or all of the input energy is lost by impurity radiation. This paper presents a simple analytic model of the radiation-dominated decay of a compact torus, and demonstrates that several striking features of the experiment (finite lifetime, linear current decay, insensitivity of the lifetime to density or stored magnetic energy) may also be explained by the hypothesis that impurity radiation dominates the energy loss. The model incorporates the essential features of the more elaborate 1 1/2-D simulations of Shumaker et al., yet is simple enough to be solved exactly. Based on the analytic results, a simple criterion is given for the maximum tolerable impurity density.
Date: November 11, 1981
Creator: Auerbach, Steven P.
System: The UNT Digital Library
Scanning reflection and transmission photometer for large high power laser optics (open access)

Scanning reflection and transmission photometer for large high power laser optics

The Nova OTR (overall transmittance/reflectance) photometer operates at 1.064 nm, 528 nm, or 351 nm in order to closely simulate 1st, 2nd and 3rd harmonic frequencies of the Nova fusion laser. The optic is scanned on a large XY carriage while reflectance or transmittance data is taken on-the-fly. The system is controlled by an LSI 11/23 computer which processes the data and prints out the results in hard copy form, or stores data on a memory disk. The detectors are temperature controlled to within +- 0.01/sup 0/C which aids in achieving of an absolute accuracy of +- 0.1 to +- 0.5% of full scale, depending on the operating point. The photometer is capable of scanning a large optic (1 meter in diameter) in 20 to 30 minutes.
Date: December 11, 1981
Creator: Thomas, N. L.; Robinson, W. L.; Wirtenson, G. R. & Wallerstein, E. P.
System: The UNT Digital Library