Physics307L F09:People/DePaula/Notebook/070926

Goal
Provide a measurable display of particle/wave duality of the electron. Will will attempt these measurements by creating a beam of electrons that will diffract off of a thin graphite film and create a diffraction pattern on a luminescent screen. Another option is to use magic spells to create Level 2 particle/wave duality, and summon unicorns. Because I am a level 3 rogue and cannot summon unicorns, only lesser wildabeasts, we will use the former process.

Setup
We used the diagram provided to hook up the heater and a bias voltage to the electron gun. We require a bias voltage because the heater we are using does not provide enough energy. The bias voltage adds an underlying power level that the heater then builds upon. We turned on the heater and waited a couple minutes for the cathode to heat up, then we slowly raised the high voltage meter until green light appeared on the luminescent screen. We then turned on the bias voltage. After a few painful shocks we were able to adjust the bias voltage until there were two concentric green circles appearing on the luminescent screen. The bias voltage is set at 8 volts. The electron gun works by passing current through a conductive filiment creating heat and electrons which are pulled away from the cathode cylinder by the anode. The anode has a potential running through it that pulls electrons in a beam, out of the cathode and through the graphite target.

Data Collection
Starting with the Hight Voltage [HV] at 5kV we measure the difference between the two radii of the concentric green rings.