Steve Chao & Maha Hamid

Day 1 After reviewing the syllabus for the two weeks, we moved to laboratory to take apart and rebuild two cosmic ray detector paddles. We learned that to get the most effective results, absolutely no light must enter the interior of the apparatus.

Group 1: Maha and Steve Group 2: Najla and Tahirah

1 st Attempt to Plateau Our group was assigned to work with the 6000 series counters. We placed counters 0 and 1 together in a stacked configuration and disabled counters 2 and 3. These counters were connected to a program on the computer which read their information constantly. We set the voltage of both counters to 0.70 V; increasing by 0.02 V after every minute. After every minute, we recorded the count rate and uncertainty of the counters in hexadecimal, which were converted for us in excel.

Our data yielded a plot which made it apparent that our plateau value was at 0.75 V. Note: Plateaus that appear at the near beginning or near end of a graph do not count as valid plateau values.

Performance Study 1 This performance study was definitely not a success. A performance study should look something like a normal curve with preferably one peak. We had a problem!

The Problem! We were very curious about why we ended up with a very unsuccessful graph, so we decided to inspect the material a bit. We discovered that the counters were plugged in the wrong slots. Counter 1 was plugged into the slot for counter 3. Therefore, we were not really measuring two stacked paddles, but measuring one paddle and a disabled one.

Plateau 2 We ran the plateau process once again, this time changing the voltage by 0.1 every minute. Our plateau value this time was 0.9 V, a value slightly higher than the one obtained in the first process.

Performance Test 2 Success! We finally obtained a graph worthy of a long and tedious plateau process. This graph is slightly skewed the right with one high peak coming from channel 2.

Performance for Flux Study We collected data for five days and used that data to do a flux study. A flux study studies the consistency of the events over time. A more stable graph shows the consistency of the data. The graph to the right shows the performance study for the data collected.

The Flux Study These graphs show the stability and consistency of the data collected over the elapsed time. Cosmic ray flux vs. time graph over the period of time.

The Theory of Relativity According to Einstein, time travel is possible. Time changes depending on relative speed. However, this is only relevant when looking at objects moving at speeds over 30,000,000 km/hour (close to the speed of light)

Lifetime Study We let the detectors run for approximately 18 hours (4:00pm – 10:00am) the next day. The graph to the right shows the number of decays as a function decay from the muon entered the scintillator. Muons entering the atmosphere decay with a mean time of 2.2 microseconds So traveling at close to the speed of light, they should only make it halfway through the atmosphere (5/10 km) Their existence is evidence for the theory of relativity

Shower Study We ran another data collection session over night in order to conduct a shower study. This time the paddles were un- stacked so that the coincidence of all 4 paddles would be measured, which would depict a cosmic ray shower.

Other Things We Learned Quarks are the building blocks of protons. Each proton contains three quarks, 2 up quarks and 1 down quark, giving it a total charge of 1. There is no such thing as a free quark. 2 most fundamental types of particles are quarks and leptons, which are divided into 6 “flavors”. Leptons consist of electrons and neutrinos (low mass particles with no charge) An anti-electron is a positron A graviton is a gravity force carrier Baryons are particles made of 3 quarks and Mesons are particles made of 2 quarks. Gluons hold the nucleus together and bind the quarks to one another.

Fermilab and CERN Fermilab located in Batavia near Chicago, Illinois A US Department of Energy national laboratory specializing in high-energy particle physics. 7 km in circumference CERN The European Organization for Nuclear Research the world's largest particle physics laboratory, situated in the northwest suburbs of Geneva on the Franco– Swiss border established in km in circumference, almost 4 times as big as Fermilab. At these facilities, protons are collided for the purpose of creating new particles. The muons we worked with in our lab can all be products of the experiments done at CERN and Fermilab.

THANK YOU!