Double planar wire array as a compact plasma radiation source

Abstract

Magnetically compressed plasmas initiated by a double planar wire array (DPWA) are efficient radiation sources. The two rows in a DPWA implode independently and then merge together at stagnation producing soft x-ray yields and powers of up to 11.5kJ∕cm and more than 0.4TW∕cm, higher than other planar arrays or low wire-number cylindrical arrays on the 1MA Zebra generator. DPWA, where precursors form in two stages, produce a shaped radiation pulse and radiate more energy in the main burst than estimates of implosion kinetic energy. High radiation efficiency, compact size (as small as 3–5mm wide), and pulse shaping show that the DPWA is a potential candidate for ICF and radiation physics research.

Compact wire array sources: power scaling and implosion physics.

“…Saturn short pulse experiments at 5-6 MA could establish the scaling of x-ray power and yield up to current levels relevant for a multi-pinch vacuum hohlraum on Z using this alternate load geometry. Double planar arrays also may be better suited to fulfilling ICF pulse shaping requirements than single planar arrays [54].…”

“…Perhaps higher wire number planar arrays would produce narrower pulses and higher x-ray powers more attractive for driving a hohlraum. It could also be worth studying double planar wire arrays on Saturn, in which two parallel linear arrays of wires are placed in close proximity [54]. Work on Zebra indicate they may scale more favorably than single planar arrays [35].…”

Wire ablation dynamics model and its application to imploding wire arrays of different geometries

“…Since that time numerous experiments have demonstrated that among all the other low-wirenumber loads the planar wire arrays yield the highest x-ray radiation energies and powers [9][10][11]. Two years later, the single planar array loads have been successfully tested at 3 − 5 MA currents on Saturn generator at SNL [5,13,14].…”

“…[23], has been performed on principle of adding thin current filaments to describe the momentum redistribution to plasmas ablated from the array wires. Later this approach has been justified by the successful application of the WADM to the simulation of single and nested cylindrical arrays [24] and single-and double-planar arrays [11,25,26].…”

“…This search has inspired several extensive programs for studying the wire array implosion at 1 MA currents at the university based laboratories, first at the Imperial College in UK [6,7] and later at the University of Nevada, Reno (UNR) [8][9][10][11] and Cornell University (see, for example, Ref. [12]) in the United States.…”