54 Matching Results

Search Results

Advanced search parameters have been applied.

SOME ASPECTS OF HIGH TEMPERATURE PLASMA RESEARCH WITH THE MIRROR MACHINE

Description: The major effort of the Livermore Mirror Machine group is directed toward study of plasma stabllity and confinement in mirror geometries. The status and radial density distribution and diffusion of confined plasma are briefly summarized. The ALICE Experiment (Adiabatic Lowenergy Injection and Capture Experiment) is discussed in some detnil. (W.D.M.)
Date: January 20, 1960
Creator: Post, R.F.
Partner: UNT Libraries Government Documents Department

Search for fusion power

Description: A brief review of the basics of fusion power is given. Both inertial confinement and magnetic confinement fusion are discussed.
Date: October 12, 1978
Creator: Post, R.F.
Partner: UNT Libraries Government Documents Department

Some implications for mirror research of the coupling between fusion economics and fusion physics

Description: The thesis is made that physics understanding and innovation represent two of the most important ingredients of any program to develop fusion power. In this context the coupling between these and the econmics of yet-to-be realized fusion power plants is explored. The coupling is two-way: realistic evaluations of the economic (and environmental) requirements for fusion power systems can influence the physics objectives of present-day fusion research programs; physics understanding and innovative ideas can favorably impact the future economics of fusion power systems. Of equal importance is the role that physics/innovation can have on the time scale for the first practical demonstration of fusion power. Given the growing worldwide need for long-term solutions to the problem of energy it is claimed to be crucial that fusion research be carried out on a broad base and in a spirit that both facilitates the growth of physics understanding and fosters innovation. Developing this theme, some examples of mirror-based fusion system concepts are given that illustrate the coupling here described.
Date: January 1, 1980
Creator: Post, R.F.
Partner: UNT Libraries Government Documents Department

Physics of mirror systems

Description: In recent years the emphasis in research on the magnetic mirror approach to fusion has been shifted to address what are essentially economically-motivated issues. The introduction of the Tandem Mirror idea solved in principal the problem of low Q (low fusion power gain) of mirror-based fusion systems. In order to optimize the tandem mirror idea from an economic standpoint, some important improvements have been suggested. These improvements include the thermal barrier idea of Baldwin and Logan and the axicell concept of Kesner. These new modifications introduce some special physics considerations. Among these are (1) The MHD stability properties of high energy electron components in the end cells; (2) The optimization of end-cell magnetic field configurations with the objective of minimizing equilibrium parallel currents; (3) The suppression of microstabilities by use of sloshing ion distributions. Following a brief outline of tandem mirror concepts, the above three topics are discussed, with illustrative examples taken from earlier work or from recent design studies.
Date: May 1, 1982
Creator: Post, R.F.
Partner: UNT Libraries Government Documents Department

Magnetic mirror fusion systems: Characteristics and distinctive features

Description: A tutorial account is given of the main characteristics and distinctive features of conceptual magnetic fusion systems employing the magnetic mirror principle. These features are related to the potential advantages that mirror-based fusion systems may exhibit for the generation of economic fusion power.
Date: August 10, 1987
Creator: Post, R.F.
Partner: UNT Libraries Government Documents Department

Magnetic-mirror principle as applied to fusion research

Description: A tutorial account is given of the key physics issues in the confinement of high temperature plasma in magnetic mirror systems. The role of adiabatic invariants and particle drifts and their relationship to equilibrium and stability are discussed, in the context of the various forms of mirror field geometry. Collisional effects and the development and the control of ambipolar potentials are reviewed. The topic of microinstabilities is discussed together with the means for their control. The properties and advantages for fusion power purposes of various special embodiments of the mirror idea, including tandem mirrors, are discussed.
Date: August 11, 1983
Creator: Post, R.F.
Partner: UNT Libraries Government Documents Department

Fokker-Planck equation in mirror research

Description: Open confinement systems based on the magnetic mirror principle depend on the maintenance of particle distributions that may deviate substantially from Maxwellian distributions. Mirror research has therefore from the beginning relied on theoretical predictions of non-equilibrium rate processes obtained from solutions to the Fokker-Planck equation. The F-P equation plays three roles: Design of experiments, creation of classical standards against which to compare experiment, and predictions concerning mirror based fusion power systems. Analytical and computational approaches to solving the F-P equation for mirror systems will be reviewed, together with results and examples that apply to specific mirror systems, such as the tandem mirror.
Date: August 11, 1983
Creator: Post, R.F.
Partner: UNT Libraries Government Documents Department

Anomalous transport in mirror systems

Description: As now being explored for fusion applications confinement systems based on the mirror principle embody two kinds of plasma regimes. These two regimes are: (a) high-beta plasmas, stabilized against MHD and other low frequency plasma instabilities by magnetic-well fields, but characterized by non-Maxwellian ion distributions; (b) near-Maxwellian plasmas, confined electrostatically (as in the tandem mirror) or in a field-reversed region within the mirror cell. Common to both situations are the questions of anomalous transport owing to high frequency instabilities in the non-maxwellian portions of the plasmas. This report will summarize the status of theory and of experimental data bearing on these questions, with particular reference to the high temperature regimes of interest for fusion power.
Date: August 20, 1979
Creator: Post, R.F.
Partner: UNT Libraries Government Documents Department

Magnetic mirror fusion: status and prospects

Description: Two improved mirror systems, the tandem mirror (TM) and the field-reversed mirror (FRM) are being intensively studied. The twin practical aims of these studies: to improve the economic prospects for mirror fusion power plants and to reduce the size and/or complexity of such plants relative to earlier approaches to magnetic fusion. While at the present time the program emphasis is still strongly oriented toward answering scientific questions, the emphasis is shifting as the data accumulates and as larger facilities - ones with a heavy technological and engineering orientation - are being prepared. The experimental and theoretical progress that led to the new look in mirror fusion research is briefly reviewed, the new TM and the FRM ideas are outlined, and the projected future course of mirror fusion research is discussed.
Date: February 11, 1980
Creator: Post, R.F.
Partner: UNT Libraries Government Documents Department

Magnetic mirror fusion research at the Lawrence Livermore Laboratory

Description: An overall view is given of progress and plans for pressing forward with mirror research at Livermore. No detail is given on any one subject, and many interesting investigations being carried out at University laboratories in the U.S. that augment and support efforts at Livermore are omitted.
Date: February 9, 1979
Creator: Post, R.F.
Partner: UNT Libraries Government Documents Department

Steps toward increasing Q in mirror systems

Description: Experiments such as the 2XIIB experiment at Livermore have established the ability of mirror systems to confine high temperature, high density plasmas at central beta values exceeding unity. Given these results the next tasks for the mirror approach are to explore means for increasing the energy gain factor Q and to scale up the plasma volume, both of these requirements deriving from economic constraints. This report discusses means for increasng Q, including recent improvements in the tandem mirror concept and design studies of the field-reversed mirror in the context of upcoming and proposed scaled-up mirror experiments.
Date: August 20, 1979
Creator: Post, R.F.
Partner: UNT Libraries Government Documents Department

Mirror fusion test facility

Description: The MFTF is a large new mirror facility under construction at Livermore for completion in 1981--82. It represents a scaleup, by a factor of 50 in plasma volume, a factor of 5 or more in ion energy, and a factor of 4 in magnetic field intensity over the Livermore 2XIIB experiment. Its magnet, employing superconducting NbTi windings, is of Yin-Yang form and will weigh 200 tons. MFTF will be driven by neutral beams of two levels of current and energy: 1000 amperes of 20 keV (accelerating potential) pulsed beams for plasma startup; 750 amperes of 80 keV beams of 0.5 second duration for temperature buildup and plasma sustainment. Two operating modes for MFTF are envisaged: The first is operation as a conventional mirror cell with n/sup tau/ approximately equal to 10/sup 12/ cm/sup -3/ sec, W/sub i/ = 50 keV, where the emphasis will be on studying the physics of mirror cells, particularly the issues of improved techniques of stabilization against ion cyclotron modes and of maximization of the electron temperature. The second possible mode is the further study of the Field Reversed Mirror idea, using high current neutral beams to sustain the field-reversed state. Anticipating success in the coming Livermore Tandem Mirror Experiment (TMX) MFTF has been oriented so that it could comprise one end cell of a scaled up TM experiment. Also, if MFTF were to succeed in achieving a FR state it could serve as an essentially full-sized physics prototype of one cell of a FRM fusion power plant.
Date: September 8, 1978
Creator: Post, R.F.
Partner: UNT Libraries Government Documents Department

''Ballistic damping'': a proposed method of stabilizing resonant ion cyclotron modes

Description: The essence of the idea is as follows: One or more beams of energetic ions (or neutral atoms that will become ionized) are injected, parallel to the field lines, at radii where the instability electric field has maximum amplitude (say roughly halfway between the axis and the outer radius of the plasma). While in transit through the plasma these ions acquire transverse energy by resonant acceleration, thereby extracting energy from the wave. This imparted energy is then carried out of the confined plasma by the beam particles as they exit through the far mirror. In this way the ballistic damping process introduces a damping mechanism that can be used to inhibit the growth of unstable waves and/or to damp them out before they reach unacceptably high amplitude. It is also shown that the beam power required is substantially lower than the plasma powers involved, scaling in a favorable way with increase in the size of the mirror cell.
Date: July 31, 1978
Creator: Post, R.F.
Partner: UNT Libraries Government Documents Department

Physics issues in mirror and tandem mirror systems

Description: Over the years the study of the confinement of high temperature plasma in magnetic mirror systems has presented researchers with many unusual physics problems. Many of these issues are by now understood theoretically and documented experimentally. With the advent of the tandem mirror idea, some new issues have emerged and are now under intensive study. These include: (1) the generation and control of ambipolar confining potentials and their effect on axial confinement and, (2) the combined influence of nonaxisymmetric magnetic fields (used to ensure MHD stability) and electric magnetic particle drifts on radial transport. Physics considerations associated with these two categories of issues will be reviewed, including concepts for the control of radial transport, under study or proposed.
Date: June 15, 1984
Creator: Post, R.F.
Partner: UNT Libraries Government Documents Department

Physics of field reversed mirrors

Description: Since the earliest days of fusion research it has been hoped that diamagnetic currents flowing in a plasma could be used to help confine the plasma. Recently this hope has been strengthened both by theoretical advances and by experimental results made possible by technological developments. On the theoretical front analytical treatments and computer simulation studies have demonstrated equilibrium solutions existing both in the fluid limit and in the large-orbit limit. Progress has also been made in determining the conditions required for the stability of field-reversed entities. It appears that configurations of the general form of fat doughnuts, possibly elongated to napkin-ring form, represent stable states. Building on previous experimental work, several investigators have been able to create field-reversed states. One method, based on the ASTRON idea of Christofilos, traps an intense relativistic electron beams (REB) to create a field-reversing current ring. Other approaches use either the reversed field theta pinch technique or REB pulses to create field-reversing diamagnetic currents in a long cylindrical plasma. In the former method, millisecond-long field-reversing electron rings have been achieved; in the latter method field-reversed plasma states lasting 30 to 50 microseconds have been achieved. Another approach under investigation is the Field Reversed Mirror (FRM) created by the tangential injection of high current neutral beams. Plasma states that approach field reversal have been achieved by this technique.
Date: September 8, 1978
Creator: Post, R.F.
Partner: UNT Libraries Government Documents Department