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Title: Dynamics of conical wire array z-pinch implosions.

Abstract

Abstract not provided.

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1147262
Report Number(s):
SAND2007-4529J
Journal ID: ISSN 1070-664X; 522370
DOE Contract Number:
DE-AC04-94AL85000
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 14; Journal Issue: 10; Related Information: Proposed for publication in Physics of Plasmas.
Country of Publication:
United States
Language:
English

Citation Formats

Ampleford, David J., Jennings, Christopher A., Lebedev, S.V, Bland, S.N., Bott, S.C, Chittenden, J.P., Kantsyrev, V.L., Safronova, A.S., Ivanov, V.V., Fedin, D.A., Laca, P.J., Yilmaz, M.F., Nalajala, V., Shrestha, I., Williamson, K., Osborne, G., and Haboub, A.. Dynamics of conical wire array z-pinch implosions.. United States: N. p., 2007. Web. doi:10.1063/1.2795129.
Ampleford, David J., Jennings, Christopher A., Lebedev, S.V, Bland, S.N., Bott, S.C, Chittenden, J.P., Kantsyrev, V.L., Safronova, A.S., Ivanov, V.V., Fedin, D.A., Laca, P.J., Yilmaz, M.F., Nalajala, V., Shrestha, I., Williamson, K., Osborne, G., & Haboub, A.. Dynamics of conical wire array z-pinch implosions.. United States. doi:10.1063/1.2795129.
Ampleford, David J., Jennings, Christopher A., Lebedev, S.V, Bland, S.N., Bott, S.C, Chittenden, J.P., Kantsyrev, V.L., Safronova, A.S., Ivanov, V.V., Fedin, D.A., Laca, P.J., Yilmaz, M.F., Nalajala, V., Shrestha, I., Williamson, K., Osborne, G., and Haboub, A.. Mon . "Dynamics of conical wire array z-pinch implosions.". United States. doi:10.1063/1.2795129.
@article{osti_1147262,
title = {Dynamics of conical wire array z-pinch implosions.},
author = {Ampleford, David J. and Jennings, Christopher A. and Lebedev, S.V and Bland, S.N. and Bott, S.C and Chittenden, J.P. and Kantsyrev, V.L. and Safronova, A.S. and Ivanov, V.V. and Fedin, D.A. and Laca, P.J. and Yilmaz, M.F. and Nalajala, V. and Shrestha, I. and Williamson, K. and Osborne, G. and Haboub, A.},
abstractNote = {Abstract not provided.},
doi = {10.1063/1.2795129},
journal = {Physics of Plasmas},
number = 10,
volume = 14,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • A modification of the wire array Z pinch, the conical wire array, has applications to the understanding of wire array implosions and potentially to pulse shaping relevant to inertial confinement fusion. Results are presented from imploding conical wire array experiments performed on university scale 1 MA generators--the MAGPIE generator (1 MA, 240 ns) at Imperial College London [I. H. Mitchell et al., Rev. Sci Instrum. 67, 1533 (1996)] and the Nevada Terawatt Facility's Zebra generator (1 MA, 100 ns) at the University of Nevada, Reno [B. Bauer et al., in Dense Z-Pinches, edited by N. Pereira, J. Davis, and P.more » Pulsifer (AIP, New York, 1997), Vol. 409, p. 153]. This paper will discuss the implosion dynamics of conical wire arrays. Data indicate that mass ablation from the wires in this complex system can be reproduced with a rocket model with fixed ablation velocity. Modulations in the ablated plasma are present, the wavelength of which is invariant to a threefold variation in magnetic field strength. The axial variation in the array leads to a zippered precursor column formation. An initial implosion of a magnetic bubble near the cathode is followed by the implosion zippering upwards. Spectroscopic data demonstrating a variation of plasma parameters (e.g., electron temperature) along the Z-pinch axis is discussed, and experimental data are compared to magnetohydrodynamic simulations.« less
  • Over the last several years, rapid progress has been made evaluating the double-z-pinch indirect-drive, inertial confinement fusion (ICF) high-yield target concept (Hammer et al 1999 Phys. Plasmas 6 2129). We have demonstrated efficient coupling of radiation from two wire-array-driven primary hohlraums to a secondary hohlraum that is large enough to drive a high yield ICF capsule. The secondary hohlraum is irradiated from two sides by z-pinches to produce low odd-mode radiation asymmetry. This double-pinch source is driven from a single electrical power feed (Cuneo et al 2002 Phys. Rev. Lett. 88 215004) on the 20 MA Z accelerator. The doublemore » z-pinch has imploded ICF capsules with even-mode radiation symmetry of 3.1 {+-} 1.4% and to high capsule radial convergence ratios of 14-21 (Bennett et al 2002 Phys. Rev. Lett. 89 245002; Bennett et al 2003 Phys. Plasmas 10 3717; Vesey et al 2003 Phys. Plasmas 10 1854). Advances in wire-array physics at 20 MA are improving our understanding of z-pinch power scaling with increasing drive current. Techniques for shaping the z-pinch radiation pulse necessary for low adiabat capsule compression have also been demonstrated.« less
  • Adding a center wire on the axis of a conical wire array produces conditions suitable for studying shear flow stabilization of the Z-pinch. The conical wire array produces and axial plasma flow while the center wire introduces a radial variation of the axial velocity. Experiments of this array configuration were preformed on the 1 MA Zebra Z-pinch generator and showed stabilization of the kink instability when a center wire was present. Comparison with equivalent cylindrical wire arrays indicates that the shear flow stabilization plays a role in the stabilization of the kink instability.
  • Adding a wire on the axis of wire arrays significantly affects the x-ray emission of the conical arrays, and much less that of the cylindrical ones. The radiation of the conical wire arrays increases with the thickness of the central wire, surpassing that of the equivalent cylindrical arrays. Significant energy is emitted early on, around the time of the conical shock formation, before the pinch stagnation.
  • Abstract not provided.