The positive rays also known as canal rays which are positively charged rays obtained from the gas molecule by removing the electrons. Positively charged rays depend only upon the nature of gas filled in the discharge tube and cannot exist without the gas present in the discharged tube.

Positive rays are produced when a stream of electrons is passed through a vapor (gas) in discharge tube. The electrons dislodge electrons from the atoms producing positively charged ions. The positive ions are accelerated towards perforated cathode. The ions pass through the slits and are further accelerated. These ions constitute a stream of positive rays.