Title :
Investigation of plasma flow redirection by an externally applied magnetic field
Author :
Plechaty, C. ; Presura, R. ; Stein, S. ; O´Brien, L. ; Haque, S. ; Tooth, M.
Author_Institution :
Nevada Terawatt Facility, Univ. of Nevada, Reno, NV, USA
Abstract :
Summary form only given. Magnetic field - plasma interactions play an important role in plasma opening switches, the closure of magnetically insulated transmission lines, as well as many other laboratory and astrophysical systems.In the past, experiments were performed to study the interaction between a plasma and an externally applied magnetic field. In these experiments, a laser was employed to produce the plasma, and the magnetic field was independently generated by a pulsed power generator. In the above mentioned cases, the plasma was observed to penetrate the field due to E x B drift. In recent experiments performed at the Nevada Terawatt Facility, an extreme case of plasma penetration was investigated. inexperiment, a plasma is produced by ablating a polyethylene (CH<;sub>;2<;/sub>;)<;sub>;n<;/sub>; target with a laser (E <; 8 J, 0.5 ns, intensity on target ~ 10<;sup>;15<;/sup>; W/cm<;sup>;2<;/sup>;) . The laser-produced plasma is then allowed to interact with a quasi-uniform applied magnetic field (7 T at the target surface). The laser-produced plasma initially expands quasi hemispherically because the plasma pressure is much larger than the magnetic pressure. As the plasma continues to expand however, the explosive plasma expansion evolves into a directed flow. The directed plasma flow becomes polarized and crosses the magnetic field at a constant velocity, due to E x B drift caused by the weak magnetization of the ions.
Keywords :
laser ablation; magnetisation; plasma magnetohydrodynamics; plasma pressure; plasma production by laser; polymers; directed plasma flow; explosive plasma expansion; externally applied magnetic field; laser ablation; laser produced plasma; magnetic flux density 7 T; magnetic pressure; magnetization; plasma flow redirection; plasma penetration; plasma pressure; polyethylene; pulsed power generator; time 0.5 ns; Ions; Lasers; Magnetic fields; Plasmas;
Conference_Titel :
Plasma Science (ICOPS), 2011 Abstracts IEEE International Conference on
Conference_Location :
Chicago, IL
Print_ISBN :
978-1-61284-330-8
Electronic_ISBN :
0730-9244
DOI :
10.1109/PLASMA.2011.5992890