*SEMINAR

PRESENTED BY-

TOPIC : GEIGER MULLER COUNTER

ARJUN K K 3rd BSc PHYSICS ROLL NO : 4505 CKGM GOVT COLLEGE PERAMBRA CALICUT

G M COUNTER

PRINCIPLE DIAGRAM

WORKING

INDRODUCTION

INDRODUCTION

G M COUNTER- GEIGER MULLER COUNTER

G M COUNTER IS AN INSTRUMENT USED FOR MEASURING IONIZING - RADIATION

IT DETECTS IONIZING RADIATION SUCH AS ALPHA PARTICLES,BETA PARTICLS AND GAMMA RADIATION USING THE IONISATION EFECT PRODUCED IN THE G M TUBE

PRINCIPLEO GAS MOLECULES GETS IONIZED WHEN ENERGETIC

PARTICLES CHARGED PARTICLE PROPAGATES THROUGH A GAS

O THE ELECTRONS PRODUED BY IONIZATION , IF ACCELARATED BY A POTENTIAL CAN CAUSE FURTHER IONIZATION OF PARTICLES,THEREBY GENERATING A LARGE NO.OF MORE ELECTRONS

DIAGRAM

DETAILS IT CONSIST OF A HOLLOW CYLENDICAL GAS

TUBE(G M TUBE) GM TUBE IS FILLED WITH INERTGAS (GENERALY

ARGON)+VAPOUR OF ETHYL ALCAHOL GM TUBE IS ENLOSED IN PARTIALLY EVACUATD

GLASS TUBE A TUNGSTEN WIRE OF 0.5mm DIAMETER IS FIXED

ALONG WITH THE AXIS OF GM TUBE TUNGSTEN WIRE CONNCTED TO +VE TERMINAL METAL GM TUBE IS CONNECTED TO –VE

TERMINAL OF HIGH TENSION BATTERY

WORKINGWHEN AN ENERGTIC PARTICLE ENTERS

GM TUBE THROUGH THE WINDOW , THE GAS MOLECULE WHICH INTERACT WITH CHARGED PARTICLE GET IONIZED

THE GENERATED ELECTRON GET ACCELARATED TOWARDS THE CENTRAL ANODE AND +VE IONES TOWARDS CATHODE

THE ACCELARATED ELECTRON CAUSE IONIATION OF MORE GAS MOLECULES

GENERATING A LARGE NO.OF ELECTRONS FROM A SMALL INTERVAL OF TIME IS CALLED AVALANCHE

THE AVALANCHE GIVES RISE TO HIGH CURRENT PULSE

FOR EACH PARTICLE ENTER IN TO THE TUBE SUCCESSIVE CURRENT PULSES ARE PRODUSED AND COUNTING IS DONE BY A SUITABLE DEVICE

THANKS