Abstract Details

Liner implosion performed with 8 cm diameter electrode apertures using deformable liner – electrode contact with full axial coverage radiography.

Author: James H. Degnan
Submitted: 2005-12-21 16:25:19

Co-authors: (list doesn't fit, see text)

Contact Info:
Air Force Research Laboratory, Directed Energy Dir
3550 Aberdeen SE
Kirtland AFB, NM   87117-5
USA

Abstract Text:
Liner implosion performed with 8 cm diameter electrode apertures using deformable liner – electrode contact with full axial coverage radiography.

J. H. Degnan, D. Amdahl, A. Brown (1), T. Cavazos (2), S. K. Coffey (1), G. G. Craddock (1), M. H. Frese (1), S. D. Frese (1), D. Gale (2), T. C. Grabowski (2), B. Guffey (1), G. F. Kiuttu (3), F. M. Lehr, J. D. Letterio, R. E. Peterkin, Jr, N. F. Roderick (4), E. L. Ruden, R. E. Siemon (5), W. Sommars (2), W. Tucker, and P. J. Turchi

Directed Energy Directorate, Air Force Research Laboratory, Kirtland AFB, NM, USA
(1) NumerEx, Albuquerque, NM, USA
(2) SAIC, Albuquerque, NM, USA
(3) VariTech Services, Albuquerque, NM, USA
(4) Department of Chemical and Nuclear Engineering, University of New Mexico, Albuquerque, NM, USA
(5) University of Nevada Reno, Nevada, USA

We obtained full axial coverage radiography of a deformable contact imploding liner. This experimental data indicates the feasibility of using a varying thickness in a long cylindrical solid liner, driven as a Z-pinch, 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 on magnetized target fusion (MTF) (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 peak current was ~ 12 megamps with ~ 10 microsecond risetime. The implosion time was 22.5 microseconds. The inner surface implosion velocity exceeded 0.5 cm/microsecond, and kinetic energy was ~ 1 megajoule.

(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).

This research was sponsored by DOE-OFES.

Characterization: A1,A2

Comments:

The University of Texas at Austin

Innovative Confinement Concepts Workshop
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