Axial and temporal gradients in Mo wire array Z pinches

Journal Article · Tue Mar 01 04:00:00 EST 2005 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.1840666· OSTI ID:20698380

LePell, P D; Hansen, S B; Shlyaptseva, A S; Coverdale, C; Deeney, C; Apruzese, J P; Fournier, K B; Safronova, U I ^[1]

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1. Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

Three nested molybdenum wire arrays with initial outer diameters of 45, 50, and 55 mm were imploded by the {approx}20 MA, 90 ns rise-time current pulse of Sandia's Z accelerator. The implosions generated Mo plasmas with {approx_equal}10% of the array's initial mass reaching Ne-like and nearby ionization stages. These ions emitted 2-4 keV L-shell x rays with radiative powers approaching 10 TW. Mo L-shell spectra with axial and temporal resolution were captured and have been analyzed using a collisional-radiative model. The measured spectra indicate significant axial variation in the electron density, which increases from a few times 10{sup 20} cm{sup -3} at the cathode up to {approx}3x10{sup 21} cm{sup -3} near the middle of the 20 mm plasma column (8 mm from the anode). Time-resolved spectra indicate that the peak electron density is reached before the peak of the L-shell emission and decreases with time, while the electron temperature remains within 10% of 1.7 keV over the 20-30 ns L-shell radiation pulse. Finally, while the total yield, peak total power, and peak L-shell power all tended to decrease with increasing initial wire array diameters, the L-shell yield and the average plasma conditions varied little with the initial wire array diameter.

• OSTI ID: 20698380
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 3 Vol. 12; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ELECTRON DENSITY
ELECTRON TEMPERATURE
EXPLODING WIRES
L SHELL
LONGITUDINAL PINCH
MOLYBDENUM
PLASMA DIAGNOSTICS
PLASMA PRODUCTION
X-RAY SPECTRA