Klinger Scientific Thomson Tube E/M

Objectives:
Thermionic emission of electrons
Deflection of electrons in electron and magnetic field
Estimate of specific change of an electron e/m
Investigate the deflection of electrons by electric and magnetic fields

•  Investigate the deflection of an electron beam by a magnetic field.
•  Investigate the deflection of an electron beam by an electric field.
•  Construct a velocity filter using orthogonal electric and magnetic fields.
•  Estimate the specific charge of an electron.

Principles
The Thomson tube is intended for investigating the deflection of electron beams in electrical and magnetic fields. It can be used to estimate the specific charge of an electron e/m and to determine the electron velocity v. The Thomson tube comprises an electron gun which emits a narrow, focused ribbon of cathode rays within an evacuated, clear glass bulb. A tungsten filament hot cathode is heated directly and the anode takes the form of a cylinder. The deflection of rays can be achieved electrostatically by means of a built-in plate capacitor formed by the pair of deflection plates or magnetically with the help of the Helmholtz coils (KSCI-HCL) magnetically. 

The cathode rays are intercepted by a flat mica sheet, one side of which is coated with a fluorescent screen and the other side of which is printed with a millimeter graticule so that the path of the electrons can be easily traced. The mica sheet is held at 10 degree to the axis of the tube by the two deflecting plates.

In a Thomson Tube the vertical deflection of a horizontal electron beam can be observed on a fluorescent screen. Such a deflection can be generated by a vertical electric field or by a horizontal magnetic field that is perpendicular to the direction of motion in the horizontal plane.

 SYSTEM COMPOSITON:
1 pc   Thomson tube       KSCI- TTUBE

1 pc   Tube holder           KSCI-HCL
1 pc   DC power supply   KSCI-HV5000A
1 pc   DC power supply   KSCI-QP500E

1 pc  Helmholtz Coils S

Leads NOT included

 Instructions for use click HERE