1. Brian Lowery July 11, 2011 Cosmic Rays

2. What are cosmic rays? • Primary • From space • Lower energy cosmic rays come from sun • Higher energy cosmic rays come from other places in the universe (example – supernova) • Mostly light elements (75% H, 25% He), but a few high mass elements, electrons, or gamma rays • High energy collision with molecules of upper atmosphere – can be 10x106 times more energetic than collisions with man-made accelerators.

3. What are cosmic rays? • Secondary • Products of the high-energy collision • Many of the secondary cosmic rays have very small half lives • Collide with more particles • Products decay • Those products decay • Etc. • Create a shower of cosmic rays • Animation • Muon • One of the decay products of particles made in the upper atmosphere

4. What is a muon? Lepton – light weight Charged – interacts via EM Force Generation II of matter -- heavier than Generation I -- Less stable(1/2 life = 2.2 μs) http://home.fnal.gov/~carrigan/pillars/Quarks.htm

5. Detecting Muons #2. PMT -- Photomultiplier Tube -- Converts light signal into electrical signal #1. Counter --scintillating material lights up when interacts with charged particle -- covered so no light can escape

6. Cosmic Ray E-Lab

7. Cosmic Ray E-Lab

8. Cosmic Ray E-Lab

9. My Goals for 2011 • Plateau multiple counters • Are we getting good data? • Performance study – noise? • Coincidence level – can we see what others set at? • Plateau Process – where do we set voltage? • How can we make it better for our classroom?

10. Resources • http://www.lorentz.leidenuniv.nl/~vanbaal/HISPARC/CosmicExtremes.pdf • http://astro.uchicago.edu/cosmus/projects/aires/protonshoweroverchicago.mpeg • http://www18.i2u2.org/cosmic/library/upload/b/ba/6000CRMDUserManual.pdf