Tandem mirror thermal barrier experimental program plan

This report describes an experimental plan for the development of the Tandem Mirror Thermal Barrier. Included is: (1) a description of thermal barrier related physics experiments; (2) thermal barrier related experiments in the existing TMX and Phaedrus experiments; (3) a thermal barrier TMX upgrade; and (4) initiation of investigations of axisymmetric magnetic geometry. Experimental studies of the first two items are presently underway. Results are expected from the TMX upgrade by the close of 1981 and from axisymmetric tandem mirror experiments at the end of 1983. Plans for Phaedrus upgrades are developing for the same period

Initial Results of the Tandem Mirror Experiment (TMX) at the Lawrence Livermore Laboratory

Initial experimental results from the Tandem Mirror Experiment (TMX) are presented. Axial profiles of the plasma density and potential necessary for electrostatically enhanced confinement of the central-cell ions have been generated and sustained for the duration of neutral-beam injection. The resulting central-cell ion confinement against axial loss is improved by a factor as large as 9 above that given by magnetic confinement alone. The plasma exhibits gross magnetohydrodynamic stability and microstability. Under some conditions, a residual level of ion cyclotron fluctuations in the end cells heats the central-cell ions and degrades their confinement

Magnetic mirror confinement of high-energy, high-density plasma

This paper summarizes results obtained from and work in progress on those experiments which have contributed significantly toward the confinement in single-cell magnetic mirror systems of plasmas close to thermonuclear conditions. Because the mirror confinement of such high-energy, high-density plasmas has been studied most extensively in the 2XIIB experiment, discussion of 2XIIB results forms a major portion of this paper. In these experiments, injection of low-energy plasma has been shown to suppress microinstabilities to sufficiently low levels that high-beta (..beta.. approx. = 1) plasmas could be achieved and sustained by cross-field injection of beams of neutral particles. Plasma confinement was found to improve with ion energy, electron temperature, and plasma size. Based on these results, a larger Mirror Fusion Test Facility (MFTF) was designed to pursue confinement scaling to higher energies and larger plasma dimensions. MFTF design parameters and construction status are briefly reviewed

Tandem mirror and field-reversed mirror experiments

This paper is largely devoted to tandem mirror and field-reversed mirror experiments at the Lawrence Livermore Laboratory (LLL), and briefly summarizes results of experiments in which field-reversal has been achieved. In the tandem experiment, high-energy, high-density plasmas (nearly identical to 2XIIB plasmas) are located at each end of a solenoid where plasma ions are electrostatically confined by the high positive poentials arising in the end plug plasma. End plug ions are magnetically confined, and electrons are electrostatically confined by the overall positive potential of the system. The field-reversed mirror reactor consists of several small field-reversed mirror plasmas linked together for economic reasons. In the LLL Beta II experiment, generation of a field-reversed plasma ring will be investigated using a high-energy plasma gun with a transverse radial magnetic field. This plasma will be further heated and sustained by injection of intense, high-energy neutral beams

TMX upgrade experimental operating plan

This document describes the operating plan for the TMX Upgrade experiment. This plan covers the period from November 1981 to March 1983 and describes how the TMX will be brought into operation, our schedules and milestones, and how we will determine if the TMX Upgrade program milestones have been met

Linear plasma-based tritium production facility

The concept presented here is an adaptation of a recently completed conceptual design of a compact high-fluence D-T neutron source for accelerated end-of-life testing of fusion reactor materials. Although this preliminary assessment serves to illustrate the main features of a linear plasma-based tritium breeder, it is not necessarily an optimized design. We believe that proper design choices for the breeder application will certainly reduce costs, perhaps as much as a factor of two. We also point out that Q (the ratio of fusion power produced to power input to the plasma) increases with system length and that the cost per kg of tritium decreases for longer systems with higher output. In earlier studies of linear two-component plasma systems, Q values as high as three were predicted. At this level of performance and with energy recovery, operating power requirements of the breeder could approach zero. 5 refs., 1 fig., 1 tab

A 14-MeV beam-plasma neutron source for materials testing

The design and performance of 14-MeV beam-plasma neutron sources for accelerated testing of fusion reactor materials are described. Continuous production of 14-MeV neutron fluxes in the range of 5 to 10 MW/m{sup 2} at the plasma surface are produced by D-T reactions in a two-component plasma. In the present designs, 14-MeV neutrons result from collisions of energetic deuterium ions created by transverse injection of 150-keV deuterium atoms on a fully ionized tritium target plasma. The beam energy, which deposited at the center of the tritium column, is transferred to the warm plasma by electron drag, which flows axially to the end regions. Neutral gas at high pressure absorbs the energy in the tritium plasma and transfers the heat to the walls of the vacuum vessel. The plasma parameters of the neutron source, in dimensionless units, have been achieved in the 2XIIB high-{beta} plasma. The larger magnetic field of the present design permits scaling to the higher energy and density of the neutron source design. In the extrapolation, care has been taken to preserve the scaling and plasma attributes that contributed to equilibrium, magnetohydrodynamic (MHD) stability, and microstability in 2XIIB. The performance and scaling characteristics are described for several designs chosen to enhance the thermal isolation of the two-component plasmas. 11 refs., 3 figs., 3 tabs

DT-burning upgrade to MFTF-B

To improve MFTF-B, one must raise the ion energy and the electrostatic confining potential. This requires higher beam energy (200 keV in this case) and, to preserve end-plug adiabaticity and hold higher plasma density in the central cell, a higher level of magnetic field. In the MFTF Upgrade we also want to incorporate the new end plug configuration first invented for the MARS reactor. This new magnet design is compared with the present MFTF-B magnet set. The differences include the addition of a pair of recircularizing coils on the ends to be used in conjunction with the end region pumping and direct converter schemes, the use of a yin-yang pair rather than a baseball-type coil in the transition, and the elimination of the axicell in favor of the simple choke coil. Also, as noted earlier, an axisymmetric mirror cell is imbedded in the central cell