Thomson e/m Tube

The Thomson e/m Tube allows an electron beam to be deflected via both electric and magnetic fields. This is the same setup that J. J. Thomson used, nearly a century ago, to successfully measure the charge-to-mass ratio of an electron. Within 20 years Millikan carefully determined the charge of the electron thus enabling its mass to be calculated. With the Thomson e/m Tube you can perform this important classical experiment to determine the charge-to-mass ratio of the electron. System includes all required accessories.

Fine Beam e/m Tube

Using the gas filled tube, the deflection of electron beams in a uniform magnetic field (with the use of Helmholtz coils) provides a means of quantitatively determining the charge-to-mass ratio of the electron, e/m.

The tube’s electron beam system consists of an indirectly heated oxide cathode, a Wehnelt cylinder and a perforated anode, in neon residual gas at a precisely set pressure. Integrated measurement marks for parallax-free determination of the diameter of the fine beam is also part of the electron beam assembly. Ionization of the gas atoms along the path of the electron produces a sharply defined, visible fluorescent beam. The tube is mounted on a base.

TEL 8481SYS2 Complete e/m System

$2499.00