Optical Thomson Scattering Measurements of Plasma Parameters in the Ablation Stage of Wire Array $Z$ Pinches

A. J. Harvey-Thompson, S. V. Lebedev, S. Patankar, S. N. Bland, G. Burdiak, J. P. Chittenden, A. Colaitis, P. De Grouchy, H. W. Doyle, G. N. Hall, E. Khoory, M. Hohenberger, L. Pickworth, F. Suzuki-Vidal, R. A. Smith, J. Skidmore, L. Suttle, and G. F. Swadling

Phys. Rev. Lett. 108, 145002 – Published 3 April 2012

Abstract

A Thomson scattering diagnostic has been used to measure the parameters of cylindrical wire array $Z$ pinch plasmas during the ablation phase. The scattering operates in the collective regime ( $α > 1$ ) allowing spatially localized measurements of the ion or electron plasma temperatures and of the plasma bulk velocity. The ablation flow is found to accelerate towards the axis reaching peak velocities of $1.2 - 1.3 \times 10^{7} cm / s$ in aluminium and $\sim 1 \times 10^{7} cm / s$ in tungsten arrays. Precursor ion temperature measurements made shortly after formation are found to correspond to the kinetic energy of the converging ablation flow.

Received 20 October 2011

DOI:https://doi.org/10.1103/PhysRevLett.108.145002

Authors & Affiliations

A. J. Harvey-Thompson^1,*, S. V. Lebedev¹, S. Patankar¹, S. N. Bland¹, G. Burdiak¹, J. P. Chittenden¹, A. Colaitis¹, P. De Grouchy¹, H. W. Doyle¹, G. N. Hall¹, E. Khoory¹, M. Hohenberger², L. Pickworth¹, F. Suzuki-Vidal¹, R. A. Smith¹, J. Skidmore¹, L. Suttle¹, and G. F. Swadling¹

¹Blackett Laboratory, Imperial College, London, SW7 2BW, United Kingdom
²Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627, USA