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Particle Showers


To determine if high energy muons, created in the upper atmosphere, can remove electrons from the atoms of lead resulting in a cascade or shower of particles.

Background Information:

It is hypothesized that a high energy muon, upon striking the surface of a material, will collide with orbital electrons.  This collision may result in an electron being ejected from the confines of the atom.  If this does occur, one could expect a shower of muons & electrons exiting the bottom surface of the material as shown in the diagram below. 

To study this phenomenon, it makes sense to look for coincidences in paddles placed side-by-side.





Control Setup Experimental Setup


1.       Run a long coincidence trial for the control setup.

2.       Set a sheet of lead (approximately 1 cm thick) approximately 15 cm above the paddles, as shown in the diagram to the right.  (Wooden blocks hold up the lead.)

3.       Run a long coincidence trial for the experimental setup.

Calculate the coincidence rate in both situations and the uncertainty in that rate. Is there a significant difference between the two set-ups?

Alter the experiment by manipulating involved variables and determine if the manipulations alter your results, for example:

         vary the distance the lead is placed above the paddles.

         vary the horizontal separation of the paddles in both the control and experimental setups.

         vary both the horizontal separation and the distance between the lead and the paddles

         vary the thickness of the lead to determine an optimal thickness for producing the greatest number of showers.

         covering only one paddle with lead.

         using a material other than lead.

         find out if the building you are in is causing showering, and if it varies with where you are in the building. Your control in this situation must be to do something with the paddles that would not show showers from the building, possibly arranging them differently.

         conducting the experiment outside.

I'm sure that you can think of others!  Good luck!