Anode Rays

In 1886, Goldstein was able to show the presence of positive rays. While carrying out experiments with discharge tubes containing perforated cathodes, he observed that some new type of luminous rays were passing through the holes in cathode.

These rays were moving in the direction opposite to that of cathode rays.

J.J Thompson later showed that these rays consisted of positively charged particles and were named as positive rays or anode rays. These rays were also called canal rays.

Origin of Anode Rays

When electrical discharge is passed through gases at very low temperature, cathode rays are produced. The cathode rays consists of streams of electrons. These electrons travel with high speeds. When these fast moving electrons strike with atoms or molecules of gas, one or more electrons are knocked off and the positively charged residues are left. These positively charged residues of atoms or molecules of the gas constitute the positive/anode rays.

Properties of Anode Rays

• Anode rays consist of positively charged particles
• Nature of these rays depends upon nature of gas used in discharge tube
• Anode rays travel in straight lines
• Anode rays get deflected by an electric field, they bend toward the negative plate
• Anode rays are also deflected by magnetic fields in a direction opposite to that of cathode rays. This shows that anode rays consists of particles having positive charge
• Ratio of charge to mass that is e/m for particles of anode rays is not equal for all gases
• Ratio of charge to mass (e/m) for anode rays is very small as compared to e/m for cathode rays. This shows that particles constituting positive rays are heavier than the cathode ray particles.