C- PHYS102 - LAB 3 - eOver-M-Final

If you do not have access to a compass go to the

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: esulting in a near vertical circular orbit. 3.2 Experimental Details 3.2.1 Procedure for Collecting Data 1. Set the apparatus on a level table away from sources of magnetic fields – current ­carrying coils or any ferromagnetic materials. 2. Optional: To reduce the effect of the earth’s local magnetic field: if you have a compass available use it to determine the direction of the local magnetic North and align the axis of the Helmholtz coils along the direction of the compass needle. If you do not have access to a compass go to the next step. 3. Press the power switch to the ON position. The instrument will begin to go through a self ­test taking about 30 ­sec. During this period all controls are locked out as the system begins to heat the cathode emitter to the proper operating temperature. After the self ­test is complete indicated by a “000” on the digital display, wait an additional 5 ­10 minute warm ­up time before starting to collect data. 4. Turn the Voltage Adjust control up to 200eV. While observing the bottom of the electron gun, notice the bluish beam traveling straight down to the envelope of the tube (Note: You will be able to see the electron beam better if you dim the room lights). Actually the electrons themselves are invisible. The orbit of the electrons is made visible by collisions between electrons and a small amount of Helium gas inside the bulb. After colliding with electrons, the orbital electrons in the helium gas atoms are excited and, upon returning to ground state, emit photons (light). This process lights up the path taken by the deflected electrons. 5. Increase the beam current by turning the Current Adjust control up. You should be able to observe the circular deflection of the beam. As the current is further incre...
View Full Document

Ask a homework question - tutors are online