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Deformable contact liner implosion performed with large diameter electrode apertures.
| Author: | Degnan J. H. |
| Coauthor: | D. Amdahl, A. Brown (a), T. Cavazos (b), S. K. Coffey (a), M. H. Frese (a), D. Gale (b), T. C. Grabo |
| Institution : | Air Force Research Laboratory, Directed Energy Directorate |
| Abstract text: | We present experimental data indicating the feasibility of using an axially varying thickness in a Z-pinch driven long cylindrical solid liner, to achieve factor ~ 17 cylindrical convergence, while using large aperture electrodes. The Al liner was 30 cm long, with 9.78 cm inner diameter for its full length, 10.0 cm outer diameter for the central 18 cm of its length, and outer diameter increased linearly to 10.2 cm at 1 cm from either electrode, and to 11 cm at electrode contacts. The two electrodes had 8 cm diameter holes or apertures, to allow injection of Field Reversed Configurations (FRC’s) in proposed future experiments (1) (2). 2D-MHD simulations as well as flash radiography and axial view fast optical photography indicate that this varying thickness results in a deforming, nearly non-sliding liner-electrode contact. The Z-pinch geometry discharge was driven by the AFRL Shiva Star 1300 microfarad capacitor bank, charged to 84 kilovolts, with ~ 44 nanoHenry initial inductance, sub-milliohm external resistance, plus a safety fuse as described in (3). The current history was similar to that for similar, uniform thickness long liner implosions with the more traditional sliding liner-electrode contact, reported in (3). The current exceeded 11 megamps with ~ 10 microsecond risetime. The implosion time was 22.5 microseconds.
(1) K.F.Schoenberg, R.E. Siemon et al, LA-UR-98-2413, 1998
(2) J. M. Taccetti, T. P. Intrator, G. A. Wurden et al, Rev. Sci. Instr. 74, 4314 (2003).
(3) J.H.Degnan et al, IEEE Transactions on Plasma Science 29, p.93-98 (2001).
(a) NumerEx, Albuquerque, NM, USA
(b) SAIC, Albuquerque, NM, USA
(c) Department of Chemical and Nuclear Engineering, University of New Mexico, Albuquerque, NM, USA
(d) University of Nevada Reno, Nevada, USA
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