1. DIRECTIONAL MUON FLUX By Laura Thorsett and Promita Nandy

2. INTRODUCTION  Testing muon flux at 8 compass directions and 3 azimuth angles.  Research Question: At which angle and direction do muons reach our detectors in the highest concentration?  Hypothesis: Most at 90°, least at 0°.  We believed that there would be no difference in flux at different compass directions.

3. THE ANGLE OF ACCEPTANCE  When stacked directly on top of one another, the angle of acceptance is approx. 168°.  This creates a problem: ~ 168° Overlap

4. THE SOLUTION  The farther apart the detectors are, the smaller the angle of acceptance.  We decided that we wanted an angle of acceptance of about 45 degrees:  To achieve this, we calculated that the (at the time) 4 detectors should be approx. 9 inches apart.

5. BOX (ONLY 2 DETECTORS)

6. PARKING GARAGE MISHAP  We wanted to take the detectors out of the building to escape the concrete walls, which are thicker in places.  We took it to the top of the parking garage.  Light leaks. Yay.  We took them back to the building and retested them, they didn’t work as well as expected.  We borrowed 2 detectors from Stu, and re-calibrated them.

7. COLLECTING DATA  First, we aligned the box with the horizon (0°): Side View Top View  We took data with the box facing N-S, NE-SW, E-W, SE-NW.  We did not need to do individual data runs for North and South or the other pairs, because at 0°, they are the same thing.

8. 45 DEGREES  For 45°, we did take separate data from each of the compass directions. Side View WestSide View East East  West

9. 90 DEGREES  We only needed to take the 90° (straight up) once. Front ViewTop ViewSide View

10. RESULTS

11. COMPARISONS

12. FROM EACH AZIMUTH ANGLE

13. 45 DEGREES BY DIRECTION

14. 0 COMPARED TO 45

15. EXTRA ALTITUDE EXPERIMENT  We measured the muon count in 3 different positions at Lick Observatory and here at SCIPP: StackedSide33 Inches Lick40634138.538.5 SCIPP3401144133.5

16. CONCLUSIONS  There was no consistent difference in the muon count in relation to compass direction.  When the box was straight up, there was a huge increase (more than doubling) in the count from the 45 degree count.

17. THE END!!!!!!!!!!!!! Thank You!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!