Chapter 19, Problem 20A

Interpretation Introduction

Interpretation:

The working principle of the Geiger Muller counter is to be described as well as the differences between the Geiger Muller counter and the scintillation counter is also be explained.

Concept introduction:

To measure and detect the particles such as alpha, beta and, gamma, the Geiger counter is used. It is made up of the metallic cylinder, filled with low-pressure gas. Its apparatus consisting of a thin tungsten metal wire which is connected to a high positive voltage, and it is present in the center of the tube. A range of multiples of 100V is applied to the gas.

Answer to Problem 20A

There is a lot of difference between the Geiger Muller counter and the scintillation counter in terms of working principle, nature of detection of radiation, voltage, and sensitivity.

Explanation of Solution

When radiation containing ionizing particles enters the tube ionizes the gas into ions and electrons. The electrons, being negatively charged moved towards the anode. As they travel through the tube repeated collisions with the gas molecules produce more secondary electrons. The production of the electron goes on in geometric progression due to which a large amount of electrons collected at the anode and generate a significant amount of electricity.

As discussed, the differences between theGeiger Muller counter and scintillation counter in the following respects,

• The GM counter works by the principle of ionization of gas whereas the scintillation counter works by the principle of the scintillation of crystals.
• In the GM counter ionization of gas produces both electrons and ions whereas the production of electrons only takes place in the scintillation counter.
• The GM counter has the capability to measure all types of radiations like alpha, beta, and gamma rays whereas the scintillation counter can only detect ionizing radiation.
• The GM counter requires needs comparatively low voltage for working thanthe scintillation counter.
• The GM counter is less sensitive and cannot detect minute quantities of radiation whereas the sensitivity of the scintillation counter is very high and can detect minute quantities of radiation.

Conclusion

There is a lot of difference between the Geiger Muller counter and the scintillation counter in terms of working principle, nature of detection of radiation, voltage, and sensitivity.