Breakdown Pulse Noise in Reactor Instrumentation Cable Systems

Breakdown pulse noise (BPN) is defined as noise pulses, which are indistinguishable from typical neutron counter pulses, generated within insulation of instrumentation cables and seals having dc voltage applied at elevated temperatures. This paper discusses possible mechanisms causing BPN and describes the experimental technique for measuring BPN. Presented data show the importance of backfill gas, density, purity and surface finish on the performance of insulators for use in cables and seals of reactor instrumentation.