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Canal Rays

a powered canal ray tube


  • Canal ray tube
  • Powerstat power supply
  • Induction coil
  • Alligator clips


Plug the induction coil into the powerstat and then connect the induction coil to the canal ray tube with alligator clips. Plug in the power supply and turn up the voltage until the tube begins to glow.


Electrons released from the cathode collide with atoms of the gas present in the tube knocking out of each of these atoms one or more additional electrons. These collisions leave behind positively charged ions. The positive ions produced move toward the cathode. Some of the positive ions flow through the perforations in the cathode disc forming canal rays. Canal rays are deflected in the opposite direction from cathode rays by both electric and magnetic fields. Since the canal rays are heavier they are deflected less by a magnetic field.