Electron Beam in Magnetic Field

PURPOSE: To demonstrate the magnetic deflection of an electron beam.

The Crookes tube contains a fluorescent screen such that a high voltage field across the electrodes will produce a glowing line on the screen where an electron beam is incident. A pole of a magnet brought close to the beam in a horizontal plane will cause the glowing line to bend up or down depending upon the magnet’s polarity.

ALWAYS USE THE MINIMUM VOLTAGE AND CURRENT NECESSARY TO OPERATE THE CROOKES TUBE.

Location

• Crookes Tube: L01, section B3
• Kilivolt Power Supply: L01, section A1
• Magnet: L01, section B2
• Cables: L01, or L35 (hanging on wall)