Effect on Muon Rate of Using Various Absorbers

Your goal is to see what effect placing various
materials in the path of the muons has on the rate at which muons pass through
the apparatus. As muons pass through a
substance, they lose energy, so you expect absorber materials to decrease the
muon rate, but we want to know how much and how it depends on characteristics
of the absorbing material. It would be
best to use the same thickness of all the different materials. However, if you can’t make them all the same
thickness, you must calculate the rate per unit thickness of absorber.

**Procedure **

You should place the detectors one above the other
with the various absorbing materials placed either above or between them. You must keep the location of the absorbing
material relative to the paddles constant throughout the experiment. Of course
you will need pieces of absorber material with a large enough surface area to
insure that muons cannot travel thru the scintillators and miss the absorber
material!! Also, of course, you will
need to intersperse your experimental runs with control runs, that is, with no
absorber at all. So, you will need to record information on the type and
thickness of the absorber material, the time and coincidences for your runes,
as well as some general information about how you set up the paddles and
absorber.

**Analysis**

First,
you need to calculate the muon rates for your various runs. Then calculate the
uncertainty in those rates, it equals the square root of the counts, divided by
the time. Next, find the difference
caused by each absorber by subtracting the rate with no absorber from the rate
with an absorber. The uncertainty in this difference is found by squaring the uncertainties
of the rates both with and without absorbers, taking the sum of those two
squares, then taking the square root of that sum! See the equations below: