Electrification of liquid nitrogen flowing in electrical insulating pipe

This paper reports results of a series of fundamental studies on electrification of liquid nitrogen flowing in electrical insulating pipes. Electrification of liquid nitrogen was confirmed by measurement with a so-called Faraday cage though the amount of charge was very small. Effects of the length of the insulating pipe, amount of liquid nitrogen, velocity of flowing nitrogen and the shape of insulating pipe on electrification are discussed based on the experimental results.