Glow discharge and Cathode Rays

(Adolf Cortel, December 2011) A homemade discharge tube is evacuated with a double stage rotary pump.A voltage around 1500 V is aplied to the electrodes (aluminum plugs at both ends of a glas tube; a narrow glass tube inserted in an electrode allows pumping up to around torr. Faraday’s dark space and striations first appear followed by a broadening of Hittorf’s dark space and a stream of canal rays behind the cathode. When Hittorf’s space is anough broad a manget allows observing the deflections of electrons (cathode rays) and the walls of the tube fluoresce.