The document summarizes a seminar on the Geiger-Muller (G-M) counter. It describes the G-M counter as a device invented in 1928 that uses a gas-filled tube to detect alpha, beta, and gamma radiation. When radiation enters the tube, it ionizes the gas molecules, producing a pulse of current between electrodes that is counted. The document discusses the construction, working principle, advantages, and applications of the G-M counter.

1. KUVEMPU UNIVERSITY
JNANASAHYADRI SHANKARAGHATTA
SEMINOR ON
G-M COUNTER
GUIDED BY
KRISHNA KULKARNI
LECTURER
DEPT.OF ENVIRONMENTAL
SCIENCE
PRESENTED BY
DASTAGEER. A
1ST YEAR M.SC
ENVIRONMENTAL SCIENCE

2. INTRODUCTION
• Geiger-Muller counter was invented by H.Geiger and E.W.
Muller in 1928. It is also called as G-M counter.
• The G-M counter is device used for the detection and
measurement of all types of radiations, such as alpha, beta and
gamma radiations.

3. CONSTRUCTION OF G.M COUNTER.
• G.M counter is a cylindrical tube with a wire at the center
consists of a pair of electrodes surrounded by a gas.
• The electrodes have a high voltage across them.
• The gas used in the tube is Helium or Argon.

4. Schematic diagram of a G.M counter-Wikipedia

5. PRINCIPLE AND WORKING
• All the nuclear radiations such as alpha, beta and gamma
radiation will ionize while passing through a gaseous medium.
This ionizing property of nuclear radiations is used for the
detection.
• In the GM counter the central wire acts as anode and the acts
as cathode.

6. • When an ionizing radiation such as alpha, beta, gamma radiation enters
the tube it ionizes some of the gas molecules in tube.
• From these ionized atoms an electron is comes out of atom, the remaining
atom is positively charged.
• Due to the high voltage in tube, it produces electric field.
• The electron that comes out of atom are attracted to positive electrode and
positively charged atoms are attracted to negative electrode.
• This produces a pulse of current in wires connected to electrodes and the
pulse is counted.

7. • Efficiency of G.M counter:
E=No. of particles of radiation detected
No. of particles of radiation emitted

8. ADVANTAGES:
• They are relatively inexpensive.
• They can detect all types of radiation
DISADVANTAGES:
• They cannot determine the exact energy of detected radiation.
• They have a very low efficiency.

9. CONCLUSION
• Geiger muller counter are regarded as one of the best radiation
detection instruments and is used widely and prominently.
• Geiger muller counters are used in numerous fields and it is
regarded as best tool for detection and measurement if ionizing
radiation.

10. Thank you