Prelimary Observations on the Henderson Data

Data was collected in 2-3 week runs between September 29 - December 8, 2004 monitoring 4 locations between depths of 2800-3900 feet below the surface.
Rates at the Henderson surface "base station" (10,337 ft above sea level)
= 2.5 times the rates at Lincoln, NE (elevation: 1189 ft)
This is precisely what was expected!

Raw 2-fold coincidence rates in the muon telescope can clearly be seen to drop from surface rates:
10 Hz (surface rate) ----» 1 Hz ----» 0.5 Hz ----» 0.3 Hz
which we of course expect to see.  We will, however, need to correct for these "raw" values for
 
1. detector efficiency (even a 95% efficient detector will miss counting 5% of the cosmic rays, requiring us to "scale up" the numbers)
2. acceptance (size/geometry - we'll want to report these rates in counts/cm2sec)
 
3. accidental coincidences collected by our detectors.

We will learn how to do all of these steps, one at a time.