Thomson Tube S
For investigating electron beams in electric and magnetic fields and determining specific charge e/m through compensation of magnetic deflection by electrostatic deflection or ascertainment of the radius of curvature of the electrons in the magnetic field. Also for estimating the speed of electrons.

An integrated plate capacitor allows electron beams to be deflected electrostatically and – by using Helmholtz coils (U18105) – magnetically. The path taken by the electron beams is rendered visible on a fluorescent screen with a scale inclined by 10° with respect to the beam axis.

Cathode heating voltage: Uh < 7.5 V, Ih < 0.4 A
Anode voltage: Ua < 5 kV
Anode current: typically Ia = 0.2 mA at Ua = 4 kV
Deflection voltage: U < 350 V
Additionally required:
U18500 Tube holder
U18505 Set of Helmholtz coils
U21060 High-voltage power supply, 6 kV
U11700 DC power supply 0-16 V, 0-5 A