Progress on Liner Implosions for Compression of FRC's

Abstract

Magnetized Target Fusion (MTF) is a means to compress plasmas to fusion conditions that uses magnetic fields to greatly reduce electron thermal conduction, thereby greatly reducing compression power density requirements (1, 2). The compression is achieved by imploding the boundary, a metal shell. This effort pursues formation of the Field Reversed Configuration (FRC) type of magnetized plasma, and implosion of the metal shell by means of magnetic pressure from a high current flowing through the shell. 93978-1-4244-2062-9/08/$25.00 ©2008 IEEE

Recent magneto-inertial fusion experiments on the field reversed configuration heating experiment

“…We report here on progress in developing the version of MIF that uses a field reversed configuration (FRC), formed by a reversed field theta discharge, and its subsequent compression by an imploding metal shell or liner, which is driven by a Z-pinch geometry discharge [3,4]. We previously reported on the successful demonstrations of imploding aluminum liners with size, radial convergence, uniformity, and implosion velocity suitable for compressing an FRC [5], and on the use of deformable liner-electrode contacts, which enable the use of large electrode apertures, suitable for FRC injection [2,6]. Our colleagues from Los Alamos (co-authors in this paper and authors and co-authors in [1][2][3][4][5][6][7][8]) and we have reported on formation of FRCs at the Los Alamos FRX-L facility, which have density ∼5×10 16 cm −3 , ion + electron temperature ∼400 eV, flux exclusion radius ∼2 cm, and lifetimes ∼10 µs [3,7].…”

“…We previously reported on the successful demonstrations of imploding aluminum liners with size, radial convergence, uniformity, and implosion velocity suitable for compressing an FRC [5], and on the use of deformable liner-electrode contacts, which enable the use of large electrode apertures, suitable for FRC injection [2,6]. Our colleagues from Los Alamos (co-authors in this paper and authors and co-authors in [1][2][3][4][5][6][7][8]) and we have reported on formation of FRCs at the Los Alamos FRX-L facility, which have density ∼5×10 16 cm −3 , ion + electron temperature ∼400 eV, flux exclusion radius ∼2 cm, and lifetimes ∼10 µs [3,7]. We have reported on the essential reproduction of such a facility and its experimental results adjacent to the AFRL Shiva Star capacitor bank, which is used to drive liner implosions [8].…”

“…We have reported on the essential reproduction of such a facility and its experimental results adjacent to the AFRL Shiva Star capacitor bank, which is used to drive liner implosions [8]. We have also previously reported twodimensional magnetohydrodynamic (2D-MHD) simulations of FRC formation, translation to liner interior, and FRC compression to multi-keV temperatures [5,6]. More recent progress includes performing liner implosions with magnetic mirror fields interior to the liner; an engineering test of the full system including mirror fields, FRC formation translation, and capture, with liner implosion operation; an experimental series to improve captured FRC lifetime by improving flux capture using RF assisted pre-ionization, optimizing the relative timing of the several capacitor discharges to form the FRCs, and by introducing rotation control using biased rings and gas puffing to enable the biased ring operation.…”