Teltron Specific charge of an electron experiment complete setup kit

Electrons in a fine beam tube are deflected into a circular path by a uniform magnetic field.

The tube contains neon gas at a precisely defined pressure so that gas atoms become ionised by collision with electrons along the path thus causing them to emit light.

This means the path of electrons can be viewed directly and the radius of the curvature can simply be measured with a ruler.

Since the accelerating voltage of the electron gun U and the magnetic field strength B are both known, the radius of the path r can be used to determine the specific charge of an electron e/m.

The complete kit contains fine beam tube , pair of 300 mm  Helmholtz coils,dc power supply 0-500v DC ,  set of 12 safety connector banana plug leads 1mtr long.