LEO SZILARD National Physics Competition

FINAL,  1998 Test sheet 1

The following appliances are available for the tests.

1 vacuum cleaner.

1 GM radiation meter and detector.

1 Bunsen burner with clamps.

1 stopwatch.

1 plastic sheet for overhead projector.

1 air balloon.

1 roll of gauze.

1 roll of isolation tape.

Collect radon and radon daughter elements for your measurements.

Observe the decay of the collectable daughters of the airborne natural radioactive noble gas, the radon. How long time do you expect for the decrease of the detectable activity to 1/32 part of the initial one?

Collection of the radon daughters takes a long time, therefore it is advisable to start with this work. During the collection process you can deal with the second task.

The GM radiation detector is used for detecting ionising radioactive radiation. It can also be used for counting ionising particles. This instrument is capable of detecting a , b and g radiation. Displaying the counts detected is possible in several ways.

  • Acoustic signal (short whistle) upon receipt of counts;
  • Above a threshold value, this acoustic signal changes over to continuous whistle;
  • The number of counts is visually displayed (independently of the whistle signal) by an LCD display counter that can manually be started and stopped.
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