1) Place the Geiger-Mueller counter box with the calibration source aligned as shown on the reverse.
2) With the headphones on, count the number of clicks
heard in a five minute interval for each of the
placements of the detector tube just behind
each of the labelled lines. The lines are all separated by 2.0cm.
Line No.
Distance to Src. Counts
Record the counts data here:
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3) Plot the Counts -vs- Distance Data. Can you determine the mean background count rate from these data? Explain and if so, record it here __________________
4) Subtract the background count rate from each of your counts data and plot these background-subtracted values against distance
5) Plot the log of the counts data -vs- the log of the
distance. What is the slope of the part of the line nearest
the source?
Why is it nearly -2?
THANKS TO S.
Kicovic, who first completed this lab on April
16th, 2003. For more info see: resources.html
and for results see
results.html