862 Matching Results

Search Results

Advanced search parameters have been applied.

Fusion research: the past is prologue

Description: At this juncture fusion research can be viewed as being at a turning point, a time to review its past and to imagine its future. Today, almost 50 years since the first serious attempts to address the daunting problem of achieving controlled fusion, we have both an opportunity and a challenge. Some predictions place fusion research today at a point midway between its first inception and its eventual maturation - in the middle of the 21st century - when fusion would become a major source of energy. Our opportunity therefore is to assess what we have learned from 50 years of hard work and use that knowledge as a starting point for new and better approaches to solving the fusion problem. Our challenge is to prove the "50 more years" prophesy wrong, by finding ways to shorten the time when fusion power becomes a reality. The thesis will be advanced that in the magnetic confinement approach to fusion open-ended magnetic confinement geometries offer much in responding to the challenge. A major advantage of open systems is that, owing to their theoretically and experimentally demonstrated ability to suppress plasma instabilities of both the MHD and the high-frequency wave-particle variety, the confinement becomes predictable from "classical," i.e., Fokker-Planck-type analysis. In a time of straitened budgetary circumstances for magnetic fusion research now being faced in the United States, the theoretical tractability of mirror-based systems is a substantial asset. In pursuing this avenue it is also necessary to keep an open mind as to the forms that mirror-based fusion power plants might take. For example, one can look to the high-energy physics community for a possible model: This community has shown the feasibility of constructing large and complex particle accelerators using superconducting magnets, vacuum chambers and complicated particle-handling technology, housed in underground tunnels that ...
Date: October 14, 1998
Creator: Post, R F
Partner: UNT Libraries Government Documents Department

Open-ended magnetic confinement systems for fusion

Description: Magnetic confinement systems that use externally generated magnetic fields can be divided topologically into two classes: ``closed`` and `open``. The tokamak, the stellarator, and the reversed-field-pinch approaches are representatives of the first category, while mirror-based systems and their variants are of the second category. While the recent thrust of magnetic fusion research, with its emphasis on the tokamak, has been concentrated on closed geometry, there are significant reasons for the continued pursuit of research into open-ended systems. The paper discusses these reasons, reviews the history and the present status of open-ended systems, and suggests some future directions for the research.
Date: May 1, 1995
Creator: Post, R.F. & Ryutov, D.D.
Partner: UNT Libraries Government Documents Department

Vacuum vessel for the tandem Mirror Fusion Test Facility

Description: In 1980, the US Department of Energy gave the Lawrence Livermore National Laboratory approval to design and build a tandem Mirror Fusion Test Facility (MFTF-B) to support the goals of the National Mirror Program. We designed the MFTF-B vacuum vessel both to maintain the required ultrahigh vacuum environment and to structurally support the 42 superconducting magnets plus auxiliary internal and external equipment. During our design work, we made extensive use of both simple and complex computer models to arrive at a cost-effective final configuration. As part of this work, we conducted a unique dynamic analysis to study the interaction of the 32,000-tonne concrete-shielding vault with the 2850-tonne vacuum vessel system. To maintain a vacuum of 2 x 10/sup -8/ torr during the physics experiments inside the vessel, we designed a vacuum pumping system of enormous capacity. The vacuum vessel (4200-m/sup 3/ internal volume) has been fabricated and erected, and acceptance tests have been completed at the Livermore site. The rest of the machine has been assembled, and individual systems have been successfully checked. On October 1, 1985, we began a series of integrated engineering tests to verify the operation of all components as a complete system.
Date: March 10, 1986
Creator: Gerich, J.W.
Partner: UNT Libraries Government Documents Department

Mechanical considerations for MFTF-B plasma-diagnostic system

Description: The reconfiguration of MFTF to a tandem mirror machine with thermal barriers has caused a significant expansion in the physical scope of plasma diagnostics. From a mechanical perspective, it complicates the plasma access, system interfaces, growth and environmental considerations. Conceptual designs characterize the general scope of the design and fabrication which remains to be done.
Date: October 19, 1981
Creator: Thomas, S.R. Jr. & Wells, C.W.
Partner: UNT Libraries Government Documents Department

Integrated operations plan for the MFTF-B Mirror Fusion Test Facility. Volume I. Organization plan

Description: This plan and the accompanying MFTF-B Integrated Operations Plan are submitted in response to UC/LLNL Purchase Order 3883801, dated July 1981. The organization plan also addresses the specific tasks and trade studies directed by the scope of work. The Integrated Operations Plan, which includes a reliability, quality assurance, and safety plan and an integrated logistics plan, comprises the burden of the report. In the first section of this volume, certain underlying assumptions and observations are discussed setting the requirements and limits for organization. Section B presents the recommended structure itself. Section C Device Availability vs Maintenance and Support Efforts and Section D Staffing Levels and Skills provide backup detail and justification. Section E is a trade study on maintenance and support by LLNL staff vs subcontract and Section F is a plan for transitioning from the construction phase into operation. A brief summary of schedules and estimated costs concludes the volume.
Date: December 1, 1981
Partner: UNT Libraries Government Documents Department

Integrated operations plan for the MFTF-B Mirror Fusion Test Facility. Volume II. Integrated operations plan

Description: This document defines an integrated plan for the operation of the Lawrence Livermore National Laboratory (LLNL) Mirror Fusion Test Facility (MFTF-B). The plan fulfills and further delineates LLNL policies and provides for accomplishing the functions required by the program. This plan specifies the management, operations, maintenance, and engineering support responsibilities. It covers phasing into sustained operations as well as the sustained operations themselves. Administrative and Plant Engineering support, which are now being performed satisfactorily, are not part of this plan unless there are unique needs.
Date: December 1, 1981
Partner: UNT Libraries Government Documents Department

Project planning and management techniques of the fast-paced TMX-Upgrade construction

Description: The Tandem Mirror Experiment-Upgrade (TMX-Upgrade) construction will be completed in 18 months at a total cost of $14.5 million. This paper describes the project planning and the management techniques used to complete the TMX-Upgrade within its allocated cost and schedule. In the planning stages of a project, before approval of the proposal, we define major project objectives, create a work breakdown structure (WBS), detail a technical description for each level of the WBS, and provide detailed bottoms-up cost estimates and summary schedules. In the operating phase, which continues throughout the project, we establish budget and schedule baselines. The reporting phase includes The Department of Energy (DOE) reviews of project status at monthly, quarterly, and semiannual intervals. These reports include cost, schedule, manpower, major procurement, and technical status information.
Date: October 26, 1981
Creator: Seberger, C.D. & Chargin, A.K.
Partner: UNT Libraries Government Documents Department

Control and diagnostic data structures for the MFTF

Description: A Data Base Management System (DBMS) is being written as an integral part of the Supervisory Control and Diagnostics System (SCDS) of programs for control of the Mirror Fusion Test Facility (MFTF). The data upon which the DBMS operates consist of control values and evaluative information required for facilities control, along with control values and disgnostic data acquired as a result of each MFTF shot. The user interface to the DBMS essentially consists of two views: a computer program interface called the Program Level Interface (PLI) and a stand-alone interactive program called the Query Level Interface to support terminal-based queries. This paper deals specifically with the data structure capabilities from the viewpoint of the PLI user.
Date: November 12, 1979
Creator: Wade, J.A. & Choy, J.H.
Partner: UNT Libraries Government Documents Department

MFTF exception handling system

Description: In the design of large experimental control systems, a major concern is ensuring that operators are quickly alerted to emergency or other exceptional conditions and that they are provided with sufficient information to respond adequately. This paper describes how the MFTF exception handling system satisfies these requirements. Conceptually exceptions are divided into one of two classes. Those which affect command status by producing an abort or suspend condition and those which fall into a softer notification category of report only or operator acknowledgement requirement. Additionally, an operator may choose to accept an exception condition as operational, or turn off monitoring for sensors determined to be malfunctioning. Control panels and displays used in operator response to exceptions are described.
Date: November 12, 1979
Creator: Nowell, D.M. & Bridgeman, G.D.
Partner: UNT Libraries Government Documents Department

Design lessons from using programmable controllers in the MFTF-B personnel safety and interlocks system

Description: Applying programmable controllers in critical applications such as personnel safety and interlocks systems requires special considerations in the design of both hardware and software. All modern programmable controller systems feature extensive internal diagnostic capabilities to protect against problems such as program memory errors; however most, if not all present designs lack an intrinsic capability for detecting and countering failures on the field-side of their I/O modules. Many of the most common styles of I/O modules can also introduce potentially dangerous sneak circuits, even without component failure. This paper presents the most significant lessons learned to date in the design of the MFTF-B Personnel Safety and Interlocks System, which utilizes two non-redundant programmable controllers with over 800 I/O points each. Specific problems recognized during the design process as well as those discovered during initial testing and operation are discussed along with their specific solutions in hardware and software.
Date: November 29, 1983
Creator: Branum, J.D.
Partner: UNT Libraries Government Documents Department

Drift waves in rotating plasmas

Description: The stability of the electron drift wave is investigated in the presence of E x B plasma rotation typical of the central cell plasma in tandem mirrors. It is shown that a rotationally-driven drift wave may occur at low azimuthal mode numbers. Conditions for rotational instabilities are derived. Quasilinear formulas are given for the anomalous transport associated with the unstable fluctuations.
Date: September 1, 1983
Creator: Horton, W. & Liu, J.
Partner: UNT Libraries Government Documents Department

ELMO Bumpy Torus (EBT) reactor

Description: The ELMO Bumpy Torus (EBT) concept has many encouraging and attractive features as a fusion reactor system. These include a high beta, magnetohydrodynamically stable equilibrium; absence of parallel currents; a large aspect ratio; the modular nature of individual sectors; no interlinking coils; ease of maintenance; steady-state operation; and economic potential. The first EBT reactor study was initiated in 1976 and provided the required starting point for continued assessment of the validity of the concept. Major refinements in plasma physics and design engineering have now resulted in a revised system description. A new design based on the present physics, practical design, and present and near-term technologies has been established. This paper discusses the details of key design elements and critical scientific and technological factors which are substantially different from other fusion reactor approaches. The paper also provides a useful summary of where the EBT program is, where it is going, and why these efforts are, in fact, self-consistent, with a motivation toward potential reactor application of EBTs.
Date: January 1, 1977
Creator: Uckan, N.A.; Dandl, R.A.; Hedrick, C.L.; Bettis, E.S.; Lidsky, L.M.; McAlees, D.G. et al.
Partner: UNT Libraries Government Documents Department

Mirror Fusion Test Facility data compression study. Final report

Description: This report is organized as follows. Discussions are given of three of the most important data compression methods that have been developed and studied over the years: coding, transforms, and redundancy reduction. (A brief discussion of how to combine and synthesize these ideas, and others, into a system is given). Specific ideas for compressing MFTF diagnostics and control data are developed. Listings and instructions for using FORTRAN programs that were compiled on the Livermore MFTF computers during the course of the study are also given.
Date: November 1, 1979
Partner: UNT Libraries Government Documents Department

Development of a Plasma Streaming System for the Mirror Fusion Test Facility

Description: The Plasma Streaming System (PSS) is an essential portion of the Mirror Fusion Test Facility (MFTF), scheduled for completion in October 1981. The PSS will develop a plasma density of at least 2 x 10/sup 12/ particles/cm/sup 3/ at the MFTF magnet centerline by injecting particles along the field lines. The plasma will have a midplane plasma radius as large as 40 cm with variable plasma particle energy and beam geometry. Minimum amounts of impurities will be injected, with emphasis on minimizing high Z materials. Each of the 60 PSS units will consist of a gun magnet assembly (GMA) and a power supply. Each GMA consists of a plasma streaming gun, a pulse magnet that provides variable beam shaping, and a fast reaction pulse gas valve.
Date: November 12, 1979
Creator: Holdsworth, T.; Clark, R.N.; McCotter, R.E.; Rossow, T.L. & Cruz, G.E.
Partner: UNT Libraries Government Documents Department

Design of a spatially resolved T/sub I/ diagnostic system for EBT-S

Description: A diagnostic neutral beam system is being designed to provide spatially resolved measurements of T/sub I/ on EBT-S. This installation will be the first step toward testing neutral beam heating in an EBT geometry and must be designed to be compatible with the intense microwave environment (isolation) and with the steady-state nature of EBT (particle control). The beam system will inject an intense (approx. .300 mA/cm/sup 2/) monoenergetic neutral beam (approx. .5 cm diam) perpendicular to the lines of sight of an existing four-channel charge exchange neutral analyzer. The resolution volume, defined as the intersection volume of beam and detector-line-of-sight will be approx. 1 cm/sup 3/. The beam source will be a 20 kV single aperture reflex arc (SARA) source. The system is being designed to operate either steady state or chopped at 50% duty cycle for long-time synchronous detection. Design criteria for selection of source parameters and anticipated results will be discussed.
Date: January 1, 1979
Creator: Glowienka, J.C.
Partner: UNT Libraries Government Documents Department

Design of a hyperbolic microwave metallic lens

Description: Due to problems caused by multiple reflections in the cavity walls of the EBT fusion research device, the use of a horn becomes important for the directivity of waves in the millimetric range. An ordinary dielectric lens cannot be used because of plasma-wall interactions. Microwave metallic lenses, designed to focus the energy into a plane wave, can improve the directivity considerably. By implementing a 70-GHz standard-gain horn with a delay-type hyperbolic lens, which consists of a solid metallic disk with a number of equal size small holes has indicated a gain of 15 dB over the no lens case.
Date: December 1, 1979
Creator: Uckan, T.
Partner: UNT Libraries Government Documents Department

Fabrication of ion source components by electroforming

Description: Several components of the Oak Ridge National Laboratory (ORNL)/Magnetic Fusion Test Facility (MFTF-B) ion source have been fabricated utilizing an electroforming process. A procedure has been developed for enclosing coolant passages in copper components by electrodepositing a thick (greater than or equal to 0.75-mm) layer of copper (electroforming) over the top of grooves machined into the copper component base. Details of the procedure to fabricate acceleration grids and other ion source components are presented.
Date: January 1, 1983
Creator: Schechter, D.E. & Sluss, F.
Partner: UNT Libraries Government Documents Department