Experimental simulation of electrical breakdown in partially enclosed structures in the space environment

The use of high voltage systems in the space environment is characterized by extreme conditions such as non-uniform fields, Nd/(Nd)/sub m/ < < 1, the presence of magnetic fields (geomagnetic or induced by current carrying structures) and the space plasma. This paper presents breakdown measurements in a simulated space environment. The experimental chamber, 2.34 m in diameter, 6.5 m long can be filled with a homogeneous plasma and atomic species of molecular gases. Breakdown experiments were performed with spherical anodes in different gases such as Argon, Nitrogen, air, and Oxygen, with and without plasma. The breakdown voltage is, at low pressures, a double-valued function of the B-field with a critical field below which no bulk breakdown occurs. Breakdown curves and critical B-fields versus pressure for different gases are presented.