1. The Use of Cosmic Ray Detectors and the Effect of Various Electron-Absorbing Steel Orientations Ben Mullins, J. Chorny, A. Todd, and Dr. D. Karmgard ND QuarkNet, QuarkNet Center at Notre Dame, South Bend, IN 46617

2. Brief Background Info Muons and electrons have the same charge When trying to detect just muons, electrons provide inaccurately high count results.

3. Project GRAND at Notre Dame Gamma Ray Astrophysics at Notre Dame

4. GRAND Project GRAND has array of 64 detectors Use 8 levels, or planes, of detectors. Between planes 6 and 7, there is a 2 inch steel absorber plate absorber is used to stop or slow electrons and help identify just muons http://www3.nd.edu/~grand/. 15 July 2013.

5. RET Project Vary positions of steel absorber plates relative to the detector planes Vary thickness of the steel plates How do these variances affect muon detection?

6. Materials and Methods Six-layer stand

7. Materials and Methods (cont.) Three 0.75 in. absorber plates 1. Single layer on one level 2. Single layer on two of three levels 3. Single layer on all three levels 4. Double layer on one level 5. Triple layer above all counters

8. Results Control: No Steel Average Coincidence = 1491

9. Results Single Layer Steel on Every Level Average Coincidence = 1245

10. Results Double Layer Between Counter 3 and 4 Average Coincidence = 1446

11. Results Triple Layer Steel Above Counter 1 Average Coincidence = 1504

12. Discussion/Conclusion When steel is placed above a counter scaler counts decrease When multiple levels of single layer steel is placed between the counters coincidence counts decrease Steel thickness between only two counters had little effect on the scaler and coincidence counts