Geiger muller counter
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The document summarizes the Geiger-Müller counter, an instrument used to detect ionizing radiation such as alpha particles, beta particles, and gamma rays. It describes the history and development of the counter, from its original detection principle discovered in 1908 to its modern form using a Geiger-Müller tube. The operating principle is explained, where ionization events in an inert gas-filled tube produce electrical pulses that are counted and displayed. Different readout types including counts per second and absorbed dose are discussed. Applications include detection of radioactive materials and environmental monitoring for radiation levels.
Geiger muller counter
- 1. Geiger Muller Counter AVS College of Arts and Science, Salem Presented By: Britto Samuel, I Msc Biotechnology, Department of Biotechnology AVS College of Arts & Science,
- 2. Introduction • The Geiger counter is an instrument used for measuring ionizing radiation • It detects ionizing radiation such as alpha particles, beta particles and gamma rays using the ionization effect produced in a Geiger–Müller tube • It is perhaps one of the world's best-known radiation detection instruments
- 3. History • The original detection principle was discovered in 1908 • The development of the Geiger-Müller tube in 1928 that the Geiger-Müller counter became a practical instrument. • It has been very popular due to its robust sensing element and relatively low cost.
- 5. GM Counter Using for Ukraine Military Purpose
- 6. Operating Principle • A Geiger counter consists of a Geiger-Müller tube, the sensing element which detects the radiation, and the processing electronics – Results in Display • Geiger-Müller tube is filled with an inert gas such as helium, neon, or argon at low pressure, to which a high voltage is applied • Tube briefly conducts electrical charge when a particle or photon of incident radiation makes the gas conductive by ionization
- 8. Operating Principle • The ionization is considerably amplified within the tube by the Townsend Discharge effect to produce an easily measured detection pulse • This large pulse from the tube makes the G-M counter cheap to manufacture, as the subsequent electronics is greatly simplified. • The electronics also generates the high voltage, typically 400–600 volts
- 10. Count per second • The number of ionizing events displayed either as a count rate, commonly "counts per second“ • The counts readout is normally used when alpha or beta particles are being detected Absorbeddose • More complex to achieve display of radiation dose rate, displayed in a unit such as the sievert • Normally used for measuring gamma or X-ray dose rates
- 11. How it works?
- 12. How it works? • Radiation (dark blue) is moving about randomly outside the detector tube. • Some of the radiation enters the window (gray) at the end of the tube. • When radiation (dark blue) crash with gas molecules in the tube (orange), it causes ionization: some of the gas molecules are turned into positive ions (red) and electrons (yellow). • The positive ions are attracted to the outside of the tube (light blue). • The electrons are attracted to a metal wire (red) running down the inside of the tube maintained at a high positive voltage. • Many electrons travel down the wire making a burst of current in a circuit connected to it. • The electrons make a meter needle deflect and, if a loudspeaker is connected, you can hear a loud click every time particles are detected.
- 13. Application • For the detection of alpha and beta particles • To detect radioactive rocks and minerals in the course of mineral prospecting or as a mineral collector • To check for environmental levels of radioactivity • For Fire and Police first responders to a analysis for making an initial determination of radiation risk.
- 14. Thank You Presented By: Britto Samuel, I Msc Biotechnology, Department of Biotechnology, AVS College of Arts & Science,