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Magnetized Target Fusion (MTF) requires the fast compression of hot, dense plasmas by a conducting liner. We have used two-dimensional MHD calculations to study the electromagnetic implosion of metallic liners driven by realistic current waveforms. Parametric studies have indicated that the liner should reach velocities of 3-20 k d s , depending on the magnetic field configuration, and reach convergence ratios (initial radius divided by final radius) of at least 10. These parameters are accessible with large capacitor bank power supplies such as SHWA or ATLAS, or with magnetic flux compression generators. One issue with the high currents that are required to implode the liner is that Ohmic heating will melt or vaporize the outer part of the liner. Calculations have shown that this is a realistic concern. We are currently addressing questions of liner instability and flux diffusion under MTF conditions. Another issue is that the magnetic fields needed to inhibit thermal losses to the walls will also heat, melt, or vaporize the inner wall surfaces. For initial fields between 5-50 Tesla, the wall heating is significant but does not result in rapid melting. As the implosion evolves, flux compression leads to fields in excess of 100 Tesla. Calculations which include flux diffusion, Ohmic heating, and realistic material properties show that a significant fraction of the inner surface of an aluminum liner will have melted and vaporized in the final microsecond of implosion. It is not clear at this time that such material mixes will the hot plasma. We are conducting studies to determine the extent of wall-plasma interaction under these conditions. Magnetized Target Fusion (MTF) is an approach to fusionwhere a preheated and magnetized plasma is adiabatically compressed to fusion conditions. Successful MTF requires a suitable initial target plasma with a magnetic field of a1 least 5 T in a closed-field-line topology, a density of roughly 10l8 ~m -~, a temperature of at least 50 eV but preferably closer to 300 eV, and must be free of impurities which would raise radiation losses. The goal of these experiments is to demonstrate plasma conditions meeting the requirements for an MTF initial target plasma. The plasma is produced by driving a z-directed current of 1-2 MA through either a static gas fill or a 38 pm diameter polyethylene fiber. The data obtained from an array of filtered photodiodes is used to estimate the plasma temperature. The filter material and thickness for each diode is chosen such that the lowest absorption edge for each is at a successively higher energy, covering the range from a few eV to 5 keV. The analysis assumes a fully stripped optically thin plasma which radiates as either a blackbody, a bremsstrahlung emitter, or a group of emission lines (gaussian-like). 288

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Magnetized Target Fusion (MTF) is an approach to fusion where a preheated and magnetized plasma is adiabatically compressed to fusion conditions.',2 Successful MTF requires a suitable initial target plasma with an embedded magnetic field of at least 5 T in a closed-field-line topology, a density of roughly lo1' ~r n-~, a temperature of at least 50 eV, and must be free of impurities which would raise radiation losses. Target plasma generation experiments are underway at Los Alamos National Laboratory using the Colt facility; a 0.25 MJ, 2-3 ps rise-time capacitor bank. The goal of these experiments is to demonstrate plasma conditions meeting the minimum requirements for a MTF initial target plasma. In the first experiments, a Z-pinch is produced in a 2 cm radius by 2 cm high conducting wall using a static gas-fill of hydrogen or deuterium gas in the range of 0.5 to 2 torr. Thus far, the diagnostics include an array of 12 B-dot probes, framing camera, gated OMA visible spectrometer, time-resolved monochrometer, filtered silicon photodiodes, neutron yield, and plasma-density interferometer. These diagnostics show that a plasma is produced in the containment region that lasts roughly 10 to 20 ps with a maximum plasma density exceeding lo1' ~m-~. The experimental design and data are presented.

Magnetized Target Fusion (MTF) is an approach to fusion where a preheated and magnetized plasma is adiabatically compressed to fusion conditions.',2 Successful MTF requires a suitable initial target plasma with an embedded magnetic field of at least 5 T in a closed-field-line topology, a density of roughly lo1' ~r n-~, a temperature of at least 50 eV, and must be free of impurities which would raise radiation losses. Target plasma generation experiments are underway at Los Alamos National Laboratory using the Colt facility; a 0.25 MJ, 2-3 ps rise-time capacitor bank. The goal of these experiments is to demonstrate plasma conditions meeting the minimum requirements for a MTF initial target plasma. In the first experiments, a Z-pinch is produced in a 2 cm radius by 2 cm high conducting wall using a static gas-fill of hydrogen or deuterium gas in the range of 0.5 to 2 torr. Thus far, the diagnostics include an array of 12 B-dot probes, framing camera, gated OMA visible spectrometer, time-resolved monochrometer, filtered silicon photodiodes, neutron yield, and plasma-density interferometer. These diagnostics show that a plasma is produced in the containment region that lasts roughly 10 to 20 ps with a maximum plasma density exceeding lo1' ~m-~. The experimental design and data are presented.

The Los Alamos National Laboratory Colt facility has been used to create target plasma for Magnetized Target Fusion (MTF). The primary results regarding magnetic field, plasma density, plasma temperature, and hot plasma lifetime are summarized and the suitability of these plasma targets for MTF is assessed.