Artículo
Wire array experiments in a low impedance and low current generator
Fecha
2015-03Registro en:
Journal of Physics: Conference Series. Volume 591, Issue 1. 24 March 2015. Article number 01202615th Latin American Workshop on Plasma Physics, LAWPP 2014 and 21st IAEA TM on Research Using Small Fusion Devices, RUSFD 2014. San Jose. 27 January 2014through 31 January 2014. Code 113197
1742-6588
10.1088/1742-6596/591/1/012026
Autor
Cabrini, Nibaldo
Pavez, Cristian
Avaria, Gonzalo
San Martin, Patricio
Veloso, Felipe
Zúñiga, Barbara
Sepúlveda, Adolfo
Soto, Leopoldo
Institución
Resumen
In this work, a preliminary study about the behavior of a low impedance
generator on different wire array configurations is reported. The experimental measurements
were carried out on a small multi-purpose generator (1.2μF, 345J, 47.5nH, T/4=375 ns and
Z=0.2 in short circuit) which produces currents up to 122 kA with 500 ns quarter period,
when a charging voltage of 24kV and a wire load are used. Two types of configurations were
tested: parallel wires (two and four) and X-pinch configurations. The experiments were carried
out on W, Al, and Cu wires with different diameters. The discharge was characterized by
means of a set of diagnostics which included: Rogowski coil; filtered PCD detector; filtered
PIN diode; gated VUV/soft X-ray pinhole camera, Shadow diagnostic and dark field Schlieren
technique. From the set of experimental results, the following observations can be established:
(i) The generator is highly sensitive to the changes of load impedance due to its low impedance
design. (ii) Every shot shows a dip in the current derivative signal shortly after the discharge
onset time (from 6 to 40 ns), which is inversely related to the load resistance. (iii) Both
configurations show a similar dynamic to those observed in experiments of higher current and
shorter quarter period. (iv) At the X-pinch experiments, two or more hard X-ray bursts are
detected, around 200 ns from the current onset time. These X-ray bursts are correlated with the
dips observed in the current derivative signal.