Join TSR now and get all your revision questions answeredSign up now

Geiger Muller Tube Watch

    • Thread Starter
    Offline

    0
    ReputationRep:
    can Gieger muller tubes only be used RELIABLY to dected neutral particles?
    charged particles will immidiatley move towards the electrodes and produce a pulse of electricity hence making results unreliable if they ionise a particle on their way as well!!

    Also what would happen if the same source of ionising radiation ionised two particles - won't this be detected as two particles by the GM tube even though ONLY 1 is present?
    Offline

    2
    ReputationRep:
    (Original post by ilovemath)
    can Gieger muller tubes only be used RELIABLY to dected neutral particles?
    charged particles will immidiatley move towards the electrodes and produce a pulse of electricity hence making results unreliable if they ionise a particle on their way as well!!

    Also what would happen if the same source of ionising radiation ionised two particles - won't this be detected as two particles by the GM tube even though ONLY 1 is present?
    No, because the voltage in the GM tube is high enough for the charged species produced in the initial ionisation event to gain enough energy that they cause secondary ionisations, and the charged species produced in this way also migrate to the electrode. So an ionisation event triggers an 'avalanche' and a GM tube gives a signal which is not proportional to the energy dissipated.
    • Thread Starter
    Offline

    0
    ReputationRep:
    (Original post by Cora Lindsay)
    No, because the voltage in the GM tube is high enough for the charged species produced in the initial ionisation event to gain enough energy that they cause secondary ionisations, and the charged species produced in this way also migrate to the electrode. So an ionisation event triggers an 'avalanche' and a GM tube gives a signal which is not proportional to the energy dissipated.
    so does the tube measure the number of pulses of current (i.e: avalanches) and we say that equals (approx) the number of ionising particles of radiation?
    Offline

    2
    ReputationRep:
    (Original post by ilovemath)
    so does the tube measure the number of pulses of current (i.e: avalanches) and we say that equals (approx) the number of ionising particles of radiation?
    That's pretty much it- the more pulses, the more intense the radiation.
 
 
 
Poll
How are you feeling about Results Day?

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Quick reply
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.