PASCO SE-9629 Product Manual

Electr Electron Char on Charge-t
SE-9629
About the Product About the Pr oduct
The e/m apparatus (Electron Charge-to-Mass Ratio) provides a simple
method for measuring e/m, the charge to mass ratio of the electron.
The method is similar to that used by J.J. Thomson in 1897. A beam of
electrons is accelerated through a known potential, so the velocity of
the electrons is known. A pair of Helmholtz coils produces a uniform
and measurable magnetic field at right angles to the electron beam.
This magnetic field deflects the electron beam in a circular path.
The e/m apparatus also has deflection plates that can be used to
demonstrate the effect of an electric field on the electron beam. This
can be used as a confirmation of the negative charge of the electron,
and also to demonstrate how an oscilloscope works.
A unique feature of the e/m tube is that the socket rotates, allowing
the electron beam to be oriented at any angle (from ±30 degrees)
with respect to the magnetic field from the Helmholtz coils. You can
therefore rotate the tube and examine the vector nature of the
magnetic forces on moving charged particles.
ge-to-Mass Ratio o-Mass Ratio
What's Included What' s Included
• e/m Tube (SE-9651A)
• Helmholtz Coils and Base (SE-9626)
• Tunable DC (Constant Voltage) Power Supply II (SE-9644)
• Tunable DC (Constant Current) Power Supply (SE-9622)
Product Guide
012-14265C
Electron Charge-to-Mass Ratio | 1