Magnetic Fields I: $e/m$ of electrons

• Magnets (can be used to divert the beam if there is a dead spot on the CRT screen)
• “Exposed” CRT, if available (can be used to show the inside workings, especially the deflection plates)
• Extra spare parts, especially the following:
  • Multimeters
  • 500 V power supplies
  • 50 V/2 A power supplies
  • CRT
• Fuse repair kit, including the following:
  • Extra batteries (AAA)
  • Extra fuses (500 mA or 630 mA)
  • Philips screwdriver (medium-size)
  • Flathead screwdriver (small-size)

Also, set up one $e/m$ “demo” using the old setup.

• e/m apparatus
• 500 V power supply
• Battery eliminator (6 A supply)

Wire the demo and leave connected between labs.

• The accelerator voltage can be supplied by only the B+ (0-400 V) supply and needs to be connected via “com” and “+” jacks.
• Set the battery eliminator voltage limit (bottom knob) to be between 6 and 9 V, and use the current adjust(upper knob) to change the current to the coils.
• Tube takes 30-60 seconds to warm up when first turned on.

• CRT
• C-clamp
• 500 V power supply
• 50 V/2 A power supply
• 2 multimeters

On the 50 V/2A power supplies…

• …turn the current limit up to max (2 A), and
• …check the overload button (and reset if necessary).

Check the multimeters to make sure there aren't blown 500 mA fuses.