Fine Beam Tube

Access to real data from which users can determine a fundamental electron property.

Background and nature of the task
By equating the force required for the circular motion of an electron with the magnetic component of the Lorentz force, measurements of current, voltage and distance may be used to evaluate the charge to mass ratio of the electron. The magnetic field is provided by two coils arranged in a Helmholtz configuration. Start by viewing the video briefing on the "Experimental set-up" below. Then read through the "Experimental guide" which gives the mathematical basis for the measurement and recommends the way to approach the experiment. Start by viewing the video briefing on the "Experimental set-up" below. Then read through the "Experimental guide" which gives the mathematical basis for the measurement and recommends the way to approach the experiment.

Duration and pattern of use
This activity should take approximately 2-5 hours including briefing materials, background and final analysis.

 Last updated: 18.11.2015

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