Discharge through gases

Description: Using experiments, animation and diagrams, this film shows and explains discharge patterns in rarefied gases. Studies the phenomena produced inside a glass tube fitted with two electrodes when a high voltage is applied and the air pressure in the tube is reduced by a vacuum pump. Starting from spark discharge in air, the parts of discharge are identified; deflection of cathode rays by magnetic or electrostatic fields, ionization by collision, breakdown voltage and excitation of the atom by free electrons are explained.