Variation in Muon Rate with Azimuthal Angle

 

The experiment is to determine the rate at which muons are detected as a function of their North-South-East-West direction. You are to rotate the apparatus in a horizontal plane through an angle of 180° while monitoring coincidences in the two detectors. Realize that the telescope counts muons going in either direction through it, so you are detecting muons traveling east to west at the same time as you are detecting muons traveling west to east.   Your results will probably be related to how the shielding differs in the various directions.  You may be able to repeat this experiment in different locations, indoors and out, to get different results.

 

Procedure

Mount the paddles so that they can detect horizontally traveling muons, and so the paddles can rotate in a horizontal plane. 

Runs much less than one hour would be pretty worthless for this experiment, because there aren’t as many muons traveling horizontally.   Perform a run, rotate the apparatus, and do another coincidence run.  Be sure that by the end of your experiment, you will have rotated the apparatus through 180°.  Why don’t you need to rotate the apparatus through 360°?

 

Analysis

Calculate the muon rates and the uncertainty in the rates.  A way to present your results is to graph the muon rate as a function of azimuth, where North is 000°, East is 090° and so on.  Include uncertainty bars for the count rates.

 

Were there significant differences between the different directions?  Were your results what you expected?  How did results of experiments performed in different locations compare?