Physics307L:People/Knockel/Notebook/070926

Electron's e/m Ratio

Experimentalists: Nik, where are you?

Goal

GOOALLLL!!!!! We win!!!

Equipment

All the equipment setup correctly.

• 2 weak direct current power supplies (10V and 2A are the max outputs needed)
• 1 strong direct current power supply (500V needed)
• 2 multimeters
• banana plugs
• The Device!
  • Helmholtz coil
  • Vacuum tube with helium gas and electron gun inside
  • Mirror with ticks for measuring length
  • Black covering to block out light

Setup

To plug everything in I...

• acquired The Device!
• plugged in the three power supplies into the wall and the two multimeters
• connected one of the weak power supplies into the heater for the electron gun with banana plugs and turned it on not exceeding 6.3V
• plugged in the other weak power supply into the Helmholtz coil using banana plugs, but intercepted the circuit to connect a multimeter in series to measure current, and then turned on the power to the Helmholtz coil and multimeter so there were about 2 amps flowing
• plugged in the large power supply to power the electrodes of the electron gun using banana plugs, and turned it on so that about 300V are applied
• connected a multimeter to The Device! to measure voltage across electrodes

To adjust the electron beam I...

1. turned off lights
2. waited for heater to heat up
3. adjusted voltage to electrodes and current to Helmholtz coils so that the beam made a helix
4. rotated the vacuum tube so the helix became a circle

My Procedure

I sat on my ass and took some sample data. When I do the real procedure I'll tell about it here