Physics307L:People/Knockel/Lab2: Difference between revisions
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== Electron's e/m ratio summary == | == Electron's e/m ratio summary == | ||
The e/m ratio for an electron can, in theory, be measured by seeing how an electron beam behaves in a magnetic field. Using a Helmholtz coil to generate the field and an electron gun in a vacuum tube filled with helium, a beam can be created, formed into a circle with the magnetic field, and measured since the electrons makes the helium glow. | The e/m ratio for an electron can, in theory, be measured by seeing how an electron beam behaves in a magnetic field. Using a Helmholtz coil to generate the field and an electron gun in a vacuum tube filled with helium, a beam can be created, formed into a circle with the magnetic field, and measured (since the electrons makes the helium glow). | ||
This experiment was a disaster since there was ridiculous drag from the helium and for other reasons. The only thing I could conclude was that | This experiment was a disaster since there was ridiculous drag from the helium and for other reasons. The only thing I could conclude was that | ||
Revision as of 20:59, 9 October 2007
Electron's e/m ratio summary
The e/m ratio for an electron can, in theory, be measured by seeing how an electron beam behaves in a magnetic field. Using a Helmholtz coil to generate the field and an electron gun in a vacuum tube filled with helium, a beam can be created, formed into a circle with the magnetic field, and measured (since the electrons makes the helium glow).
This experiment was a disaster since there was ridiculous drag from the helium and for other reasons. The only thing I could conclude was that
[math]\displaystyle{ \frac{e}{m} \lt 3.13\times10^{11}\frac{C}{kg} }[/math].
In my lab notebook, I go into great detail explaining the theory, why there is so much systematic error, and alternative methods for finding e/m without so much error. I, of course, also explain the setup, equipment, procedure, etc., and I give my data and calculations.
