Publications

Transformation of a tungsten wire to the plasma state by nanosecond electrical explosion in vacuum

Sarkisov, G.S.; Rosenthal, Stephen E.; Struve, Kenneth W.

Experiment demonstrates the first direct transformation of a tungsten wire core to the plasma state by Joule heating during nanosecond electrical explosion in vacuum. Energy of ∼130 eV/atom was deposited into the 12 μm W wire coated by 2 μm polyimide during the first ∼10 ns. All the metal rapidly transformed to highly ionized plasma, while the surrounding polyimide coating remained primarily in a gaseous state. This coating totally suppressed corona formation. The expansion velocity of the wire was ∼12-18 km/s, the average wire ionization at 50 ns reached ∼67% with corresponding LTE temperature of ∼1.2 eV. Explosion of bare W wire demonstrated earlier termination of the wire core heating due to shunting corona generation. Magnetohydrodynamic (MHD) simulation reproduces the main features of coated and uncoated W wire explosion. © 2008 The American Physical Society.