Title :
Time-resolved optical spectroscopy measurements of pre-pulse plasma formation on Z
Author :
Bailey, J.E. ; Carlson, A.L. ; Cuneo, M.E. ; Deeney, C. ; Lake, P. ; Spielman, R.B. ; Struve, Kenneth W. ; Stygar, William A. ; Maron, YH.
Author_Institution :
Sandia Nat. Labs., Albuquerque, NM, USA
Abstract :
Summary form only given. The compression of annular wire arrays in Z-pinch experiments produces large radiation pulses which are useful for high energy density research. The initial transformation of the wire array into a plasma shell impacts the subsequent implosion of the shell because it affects the current distribution, possibly seeding instabilities. On the Z accelerator the initial plasma is created when a /spl sim/300 kA prepulse current flows through the 240-300 wire array during a /spl sim/50 nsec period prior to the arrival of the main power pulse, approximately 100 nsec prior to the pinch. Ideally, we would like to measure the pre-pulse plasma density and temperature with nsec time resolution and sub /spl sim/100 micron two-dimensional spatial resolution. Such measurements are difficult at large accelerators, such as Z, because of limited line of sight access and low experiment rates. Nevertheless, the unique conditions produced on Z discharges imply that it is important to measure the plasma formation characteristics on Z. Our strategy is to perform an initial set of limited measurements at Z and interpret the results with the aid of models based on more detailed benchtop experiments performed elsewhere. Subsequent more-detailed measurements at Z can then be pursued.
Keywords :
Z pinch; exploding wires; plasma density; plasma diagnostics; plasma instability; plasma production; plasma temperature; 300 kA; Z; Z accelerator; annular wire arrays compression; benchtop experiments; current distribution; impacting plasma shell; plasma formation characteristics; power pulse; pre-pulse plasma density; pre-pulse plasma formation; pre-pulse plasma temperature; prepulse current flows; radiation pulses; seeding instabilities; time-resolved optical spectroscopy measurements; two-dimensional spatial resolution; Optical pulses; Performance evaluation; Plasma accelerators; Plasma density; Plasma measurements; Plasma temperature; Pulse compression methods; Spatial resolution; Spectroscopy; Wire;
Conference_Titel :
Plasma Science, 1999. ICOPS '99. IEEE Conference Record - Abstracts. 1999 IEEE International Conference on
Conference_Location :
Monterey, CA, USA
Print_ISBN :
0-7803-5224-6
DOI :
10.1109/PLASMA.1999.829548