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MARS: Mirror Advanced Reactor Study

Description: A recently completed two-year study of a commercial tandem mirror reactor design (Mirror Advanced Reactor Study (MARS)) is briefly reviewed. The end plugs are designed for trapped particle stability, MHD ballooning, balanced geodesic curvature, and small radial electric fields in the central cell. New technologies such as lithium-lead blankets, 24T hybrid coils, gridless direct converters and plasma halo vacuum pumps are highlighted.
Date: September 10, 1984
Creator: Logan, B.G.
Partner: UNT Libraries Government Documents Department

TMX supermodel

Description: The TMX Supermodel is an attempt to synthesize all presently known experimental observations and theoretical scaling laws concerning particle and energy losses into a comprehensive zero-dimensional description of plasma confinement in the center cell and plugs of TMX. A list of important loss processes and physical effects included in the present state of evolution of the supermodel is given.
Date: March 5, 1979
Creator: Logan, B.G.
Partner: UNT Libraries Government Documents Department

Summary of the MARS tandem-mirror reactor design

Description: A recently completed two-year study of a commercial tandem-mirror reactor design (Mirror Advanced Reactor Study (MARS)) is briefly reviewed. The end plugs are designed for trapped-particle stability, MHD ballooning, balanced geodesic curvature, and small radial electric fields in the central cell. New technologies such as lithium-lead blankets, 24 T hybrid coils, gridless direct converters and plasma halo vacuum pumps are highlighted. General characteristics of the MARS tandem mirror and STARFIRE tokamak reactor design are compared. A design of an upgrade of MFTF-B incorporating many of the MARS features is discussed.
Date: September 1, 1983
Creator: Logan, B.G.
Partner: UNT Libraries Government Documents Department

General ignition requirements in TMR's with drift pumping

Description: Drift pumping of collisionally trapped DT ions and thermal alpha ash in the transitions and thermal barriers of TMR plugs can be shown by simple models to dominate the central cell energy losses, requiring in fact more radial ion loss by drift pumping than axial ion loss through the potential plugs, and setting a minimum central cell length for ignition. Induced electron transport due to drift pumping is shown to be small, so grids are not needed on the direct converter to separate ion and electron currents.
Date: January 1, 1983
Creator: Logan, B.G.
Partner: UNT Libraries Government Documents Department

Mirror Advanced Reactor Study (MARS)

Description: Progress in a two year study of a 1200 MWe commercial tandem mirror reactor (MARS - Mirror Advanced Reactor Study) has reached the point where major reactor system technologies are identified. New design features of the magnets, blankets, plug heating systems and direct converter are described. With the innovation of radial drift pumping to maintain low plug density, reactor recirculating power fraction is reduced to 20%. Dominance of radial ion and impurity losses into the halo permits gridless, circular direct converters to be dramatically reduced in size. Comparisons of MARS with the Starfire tokamak design are made.
Date: March 28, 1983
Creator: Logan, B.G.
Partner: UNT Libraries Government Documents Department

An alternative strategy for low specific power reactors to power interplanetary spacecraft, based on exploiting lasers and lunar resources

Description: A key requirement setting the minimum electric propulsion performance (specific power ..cap alpha../sub e/ = kW/sub e//kg) for manned missions to Mars is the maximum allowable radiation dose to the crew during the long transits between Earth and Mars. Penetrating galactic cosmic rays and secondary neutron showers give about 0.1-rem/day dose, which only massive shielding (e.g., a meter of concrete) can reduce significantly. With a humane allowance for cabin space, the shielding mass becomes so large that it prohibitively escalates the propellant consumption required for reasonable trip times. This paper covers various proposed methods for using reactor power to propel spacecraft. 7 refs., 6 figs., 1 tab.
Date: February 2, 1989
Creator: Logan, B.G.
Partner: UNT Libraries Government Documents Department

Design of a stable tandem mirror with thermal barriers and A-cells (MFTF-B)

Description: A self-consistent design is described for a large tandem mirror experiment (MFTF-B) proposed to be constructed at the Lawrence Livermore Laboratory. Neutral-beam injected yin-yang mirror cells at each end of a 40 meter long central cell, provide MHD stability for the configuration, as in the TMX experiment. The largest potential well confining center-cell ions is generated by ECRH in auxiliary mirror cells (A-cells) added beyond the outer yin-yang mirrors. The required ECRH power (less than or equal to 1 MW) is minimized by use of thermal barriers installed at the local midplanes of each A-cell. In addition, the trapping of cold ions (n cold approx. n hot) in the local potential dips at the A-cell midplanes stabilize loss cone microstabilities. The impact of constraints imposed by neoclassical radial transport (resonant drifts), MHD stability (ballooning modes), and microstability (ion two-stream and loss cone modes) on the overall design will be assessed for the benefit of improving designs in future tandem mirror devices.
Date: April 2, 1980
Creator: Logan, B.G.
Partner: UNT Libraries Government Documents Department

Drift-pump coil design for a tandem mirror reactor

Description: This paper describes both the theory and mechanical design behind a new concept for trapped ion removal from tandem mirror end plugs. The design has been developed for the Mirror Advanced Reactor Study (MARS). The new drift-pump coils replace charge-exchange pump beams. Pump beams consume large amounts of power and seriously reduce reactor performance. Drift-pump coils consume only a few megawatts of power and introduce no added burden to the reactor vacuum pumps. In addition, they are easy to replace. The coils are similar in shape to a paper clip and are located at two positions in each end plug. The coils between the transition coil and the first anchor yin-yang serve to remove ions trapped in the magnetic well just outboard of the high field choke coil. The coils located between the anchor coil set and the plug coil set remove sloshing ions and trapped cold ions from the plug region.
Date: December 1, 1983
Creator: Logan, B. G. & Neef, W. S.
Partner: UNT Libraries Government Documents Department

Relevance of the U.S. National Ignition Facility for driver and target options to next-step inertial fusion test facilities

Description: Achievement of inertial fusion ignition and energy gain in the proposed U.S. National Ignition Facility is a prerequisite for decisions to build next-step U.S. inertial fusion facilities for either high yield or high pulse-rate. There are a variety of target and driver options for such next-step inertial fusion test facilities, and this paper discusses possible ways that the NIF, using a 1.8 MJ glass laser in both direct and indirect-drive configurations, can provide target physics data relevant to several next-step facility options. Next step facility options include the Engineering Test Facility (ETF), which needs several-Hz pulse-rates for testing relevant to Inertial Fusion Energy (IFE) development. An option for high yield, called the Laboratory Microfusion Facility (LMF), does not require such high pulse-rates, but may still benefit from driver technologies capable of much higher shot rates than possible with glass lasers. A high-pulse-rate driver could also be used for a combined ETF/LMF facility, driving multiple target chambers with a common driver. Driver technologies that could support high-pulse rates for next-step options include heavy-ion and light-ion accelerators, diode-pumped solid-state lasers (DPSSL), and krypton-flouride gas lasers. The NIF could be used to provide important data for IFE in generic areas of target chamber damage and materials responses, neutron activation and heating, tritium recovery and safety, and in performance tests of prototypical IFE targets and injection systems. In the study of ignition in both direct and indirect-drive, the NIF would explore generic ICF fuel capsule implosion physics common to all driver and target options for next-step facilities. In the following, we point out specific ways in which the NIF could be used to study target physics specifically relevant to the above-mentioned driver options for such next-step facilities, as well as how the NIF laser system itself could be relevant to the DPSSL option.
Date: April 10, 1995
Creator: Logan, B.G.
Partner: UNT Libraries Government Documents Department

The role of the NIF in the development of inertial fusion energy

Description: Recent decisions by DOE to proceed with the National Ignition Facility (NIF) and the first half of the Induction Systems Linac Experiments (ILSE) can provide the scientific basis for inertial fusion ignition and high-repetition heavy-ion driver physics, respectively. Both are critical to Inertial Fusion Energy (IFE). A conceptual design has been completed for a 1.8-MJ, 500-TW, 0.35-{micro}m-solid-state laser system, the NIF. The NIF will demonstrate inertial fusion ignition and gain for national security applications, and for IFE development. It will support science applications using high-power lasers. The demonstration of inertial fusion ignition and gain, along with the parallel demonstration of the feasibility of an efficient, high-repetition-rate driver, would provide the basis for a follow-on Engineering Test Facility (ETF) identified in the National Energy Policy Act of 1992. The ETF would provide an integrated testbed for the development and demonstration of the technologies needed for IFE power plants. In addition to target physics of ignition, the NIF will contribute important data on IFE target chamber issues, including neutron damage, activation, target debris clearing, operational experience in many areas prototypical to future IFE power plants, and an opportunity to provide tests of candidate low-cost IFE targets and injection systems. An overview of the NIF design and the target area environments relevant to conducting IFE experiments are described in Section 2. In providing this basic data for IFE, the NIF will provide confidence that an ETF can be successful in the integration of drivers, target chambers, and targets for IFE.
Date: March 16, 1995
Creator: Logan, B.G.
Partner: UNT Libraries Government Documents Department

Evolution of the tandem mirror reactor concept

Description: We discuss the evolution of the tandem mirror reactor concept from the original conceptual reactor design (1977) through the first application of the thermal barrier concept to a reactor design (1979) to the beginning of the Mirror Advanced Reactor Study (1982).
Date: March 9, 1982
Creator: Carlson, G.A. & Logan, B.G.
Partner: UNT Libraries Government Documents Department

Compact Fusion Advanced Rankine (CFARII) power cycle---Operating regimes

Description: Performance (cost/kWe and efficiency) of generic Compact Fusion Advanced Rankine (CFARII) power conversion is investigated for various working fluids, operating temperatures and pressures, and thermal power levels. A general conclusion is that good CFARII performance is found for a remarkably broad range of materials, temperatures, pressures and power levels, which gives considerable flexibility to future design studies which may apply CFARII energy conversion to specific fusion energy sources such as ICF, MICF, and Mini-PACER. 5 refs, 7 figs., 2 tabs.
Date: September 30, 1991
Creator: Logan, B.G.
Partner: UNT Libraries Government Documents Department

Fueling of tandem mirror reactors

Description: This paper summarizes the fueling requirements for experimental and demonstration tandem mirror reactors (TMRs), reviews the status of conventional pellet injectors, and identifies some candidate accelerators that may be needed for fueling tandem mirror reactors. Characteristics and limitations of three types of accelerators are described; neutral beam injectors, electromagnetic rail guns, and laser beam drivers. Based on these characteristics and limitations, a computer module was developed for the Tandem Mirror Reactor Systems Code (TMRSC) to select the pellet injector/accelerator combination which most nearly satisfies the fueling requirements for a given machine design.
Date: January 1, 1985
Creator: Gorker, G.E. & Logan, B.G.
Partner: UNT Libraries Government Documents Department

Advances in Tandem Mirror fusion power reactors

Description: The Tandem Mirror exhibits several distinctive features which make the reactor embodiment of the principle very attractive: Simple low-technology linear central cell; steady-state operation; high-..beta.. operation; no driven current or disruptions; divertorless operation; direction conversion of end-loss power; low-surface heat loads; and advanced fusion fuel capability. In this paper, we examine these features in connection with two tandem mirror reactor designs, MARS and MINIMARS, and several advanced reactor concepts including the wall-stabilized reactor and the field-reversed mirror. With a novel compact end plug scheme employing octopole stabilization, MINIMARS is expressly designed for short construction times, factory-built modules, and a small (600 MWe) but economic reactor size. We have also configured the design for low radioactive afterheat and inherent/passive safety under LOCA/LOFA conditions, thereby obviating the need for expensive engineered safety systems. In contrast to the complex and expensive double-quadrupole end-cell of the MARS reactor, the compact octopole end-cell of MINIMARS enables ignition to be achieved with much shorter central cell lengths and considerably improves the economy of scale for small (approx.250 to 600 MWe) tandem mirror reactors. Finally, we examine the prospects for realizing the ultimate potential of the tandem mirror with regard to both innovative configurations and novel neutron energy conversion schemes, and stress that advanced fuel applications could exploit its unique reactor features.
Date: May 20, 1986
Creator: Perkins, L.J. & Logan, B.G.
Partner: UNT Libraries Government Documents Department

Overview of the TIBER II (Tokamak Ignition/Burn Experimental Reactor) design

Description: The TIBER II Tokamak Ignition/Burn Experimental Reactor design is the result of efforts by numerous people and institutions, including many fusion laboratories, universities, and industries. While subsystems will be covered extensively in other reports, this overview will attempt to place the work in perspective. Major features of the design are compact size, low cost, and steady-state operation. These are achieved through plasma shaping and innovative features such as radiation tolerant magnets and optimized shielding. While TIBER II can operate in a pulsed mode, steady-state is preferred for nuclear testing. Current drive is achieved by a combination of lower hybrid and neutral beams. In addition, 10 MW of ECR is added for disruption control and current drive profiling. The TIBER II design has been the US option in preparation for the International Thermonuclear Experimental Reactor (ITER). Other equivalent national designs are the NET in Europe, the FER in Japan and the OTR in the USSR. These designs will help set the basis for the new international design effort. 9 refs.
Date: October 16, 1987
Creator: Henning, C.D. & Logan, B.G.
Partner: UNT Libraries Government Documents Department

Tandem-mirror technology demonstration facility

Description: Preliminary calculations at LLNL indicate that a Technology Demonstration Facility (TDF) consisting of a tandem mirror machine about the size of TMX could begin providing fusion nuclear engineering data as early as 1988. With high density operation based on physics already demonstrated in TMX, this machine would produce 12 MW of DT neutrons in steady-state from a plasma column 0.08 m in radius and 8 m in length. Allowing space for neutral beam injectors at each end of the column, this would permit testing of blanket modules and components at 1 MW/m/sup 2/ neutron wall load over a cylindrical surface 8 m/sup 2/ in area at a radius of 0.25 m; or one could irradiate thousands of small samples at 2 MW/m/sup 2/ at r = 0.125 m (4 m/sup 2/ area). With improved end-plug physics to be tested in TMX-Upgrade in 1982-83, the wall load at 0.25 m could be increased to 2 MW/m/sup 2/ (4 MW/m/sup 2/ at r = 0.125 m). Construction of the TDF could begin in FY84 and be completed in 4 to 5 years, at a cost roughly estimated as $700M in '81 dollars including engineering and 30% contingency.
Date: September 18, 1981
Creator: Fowler, T.K. & Logan, B.G.
Partner: UNT Libraries Government Documents Department

Exploring a unique vision for heavy ion fusion

Description: A quest for more efficient beam-to-fuel energy coupling via polar direct drive (30% overall), to enable: (1) Self-T-breeding, self-neutron-energy-absorbing, large {pi}r, T-Lean targets {at} < 4 MJ driver energies; (2) Efficient fusion energy coupling into plasma for direct MHD conversion with moderate yields < 1 GJ; (3) Balance-of-plant costs 10X lower than steam cycle (e.g., < 80 $/kWe instead of 800 $/kWe); (4) CoE low enough (<3 cts/kWehr) for affordable water and H{sub 2} fuel for 10 B people on a hot planet; and (5) Enough fissile fuel production for 38 LWR's per GW{sub fusion} if uranium gets too expensive meantime.
Date: August 6, 2007
Creator: LOGAN, B.G. & Logan, B.G.
Partner: UNT Libraries Government Documents Department

In-situ MHD energy conversion for fusion. [R]

Description: An advanced concept, in-situ MHD conversion, is described for converting fusion energy to electricity. Considerable cost savings can be realized because of the conversion of thermal energy to electricity achieved in the blanket by means of magnetohydrodynamic (MHD) generators. The external disk generator, also described, is another application of the MHD idea, which may have certain advantages over the in-situ scheme for advanced-fuel tokamaks. The feature that makes these schemes fusion-specific is the novel use of the electro-magnetic radiation naturally emitted by the plasma. The synchrotron radiation can be used either to heat the nonequilibrium MHD plasma, or possibly improve its stability. A Rankine cycle with cesium-seeded mercury as a working fluid is used in either case. Performance predictions by a quasi-one-dimensional model are presented. An experiment to determine the effect of microwave radiation on channel performance is planned.
Date: June 1, 1986
Creator: Campbell, R.B.; Logan, B.G. & Hoffman, M.A.
Partner: UNT Libraries Government Documents Department

Beam charge and current neutralization of high-charge-state heavy ions

Description: High-charge-state heavy-ions may reduce the accelerator voltage and cost of heavy-ion inertial fusion drivers, if ways can be found to neutralize the space charge of the highly charged beam ions as they are focused to a target in a fusion chamber. Using 2-D Particle-In- Cell simulations, we have evaluated the effectiveness of two different methods of beam neutralization: (1) by redistribution of beam charge in a larger diameter, preformed plasma in the chamber, and (2), by introducing a cold-electron-emitting source within the beam channel at the beam entrance into the chamber. We find the latter method to be much more effective for high-charge-state ions.
Date: October 29, 1997
Creator: Logan, B.G. & Callahan, D.A.
Partner: UNT Libraries Government Documents Department

Physics basis for an axicell design for the end plugs of MFTF-B

Description: The primary motivation for conversion of MFTF-B to an axicell configuration lies in its engineering promise as a reactor geometry based on circular high-magnetic-field coils. In comparing this configuration to the previous A-cell geometry, we find a number of differences that might significantly affect the physics performance. The purpose of the present document is to examine those features and to assess their impact on the performance of the axicell, as compared to the A-cell configuration, for MFTF-B. In so doing, we address only those issues thought to be affected by the change in geometry and refer to the original report Physics Basis for MFTF-B, for discussion of those issues thought not to be affected. In Sec. 1, we summarize these physics issues. In Sec. 2, we describe operating scenarios in the new configuration. In the Appendices, we discuss those physics issues that require more detailed treatment.
Date: April 21, 1982
Creator: Baldwin, D.E. & Logan, B.G. (eds.)
Partner: UNT Libraries Government Documents Department

Localized electron-cyclotron heating and current drive in the TIBER-II reactor study

Description: A scenario is shown for launching 10 MW of 450 GHz extraordinary-mode electron-cyclotron waves into a TIBER-II equilibrium. Localized, high-efficiency current drive near but outside the q = 2 surface causes substantial reduction in the current gradients that may play a role in major disruptions and anomalous transport. The same launch geometry shows promise for heating the plasma core during startup.
Date: May 1, 1987
Creator: Smith, G.R.; Logan, B.G. & Kritz, A.H.
Partner: UNT Libraries Government Documents Department