Experiment: Fine-Beam Tube (115 V, 50/60 Hz)

Price Request

Ask a question

Description
Delivery scope

Thematic focus:_..

•	Demonstrate the deflection of electrons in a uniform magnetic field into a closed circular path
•	Determine the Helmholtz current I_H as a function of the accelerating voltage of the electron gun U for a constant path radius r.

Experiment description:_..

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 the 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.