Week+of+September+24-30

On September 26th, we began working with Ken and Michael from Elkhart Central on the Cosmic Ray e-Lab. We arrived at 3:45, and their experiment running the cosmic ray detector was already underway. We assisted in adjusting the angle of the detector and uploading data onto the CRiL website. The angle was adjusted 10 degrees every 5 minutes; the goal of the experiment is to analyze the frequency of cosmic rays at different angles. Flux is muons per centimeter per second. We ran a flux study on the data and adjusted the bin width; first we tried a bin width of 300 seconds, but the data was all over th

e place. Then we changed the bin width to 30 seconds, and again it showed a bump in flux and a section of low outliers. Finally, we tried a 10 second bin width, but the data still did not show consistency. We considered the possibility of human error affecting the machine while adjusting the angle, and ultimately we decided to take new data, but adjust for fewer data points with longer duration (every 15 degrees for 10 minutes). We discussed twofold coincidences and the accuracy that lies therein; if a muon was passing through the detector plates rather than just a phantom signal from noise or the machine. After a while of tinkering, we concluded that the light was providing infinite photons that skewed the data and that the cosmic ray detector must function in the dark to avoid the light leak. The results of the trial with the light leak accounted for are shown below.

Meanwhile, John explained Eta and Phi coordinates to me and got Alex, Jeremiah, and I started on the Many Eyes website. Phi coordinates measure angles on the x-y plane in radians (similar to the unit circle). From the right side, angles vary from pi to negative pi, counterclockwise. Eta me

asures angles on the z plane (vertically) from -1 to 1 rather than radians or degrees. Because cosmic rays originate in space and live only a short time, they enter the atmosphere and subsequently the detector in a straight line. Also, they have the highest mass and the highest energy. I set the dot size to reflect the mass of the particle to isolate and draw attention to the larger and more energetic particles. Then, I fiddled with adjusting the x and y axes. The following combinations produced images of particular interest. The above image shows Eta1 on the y axis and mass on the x axis. The particles with greater mass (presumab

ly cosmic rays) appear to focus around 0 eta. I then switched the y-axis to represent Eta2.

This graph of Eta2 vs mass shows the particles with more mass concentrated around the same area, showing that the heavier particles from the previous screen continued a similar trajectory on a straight line. This stands apart from particle collisions because they would typically separate from each other at an angle rather than a straight line.



The y-axis of this graph now reflects the Phi1 coordinates. The heavier particles concentrate in the range of -1.2 through -2.2, which corresponds to a phi value of about -1/2 pi (approximately -1.57).

When the y-axis was switched to Phi2, the heavy particles similarly concentrate around positive 1/2 pi. This shows that their linear trajectory continued and leads me to believe that these heavy, high-energy particles are cosmic rays rather than expected particles from the collision. Then, I looked at Eta 1 vs. Eta 2 and Phi 1 vs. Phi 2 (still with dot size varying depending on mass) to see where the heaviest particles concentrated in each coordinate system. On Eta 1 vs. Eta 2, the heaviest particles concentrate around 0 on both axes. On Phi 1 vs. Phi 2, they concentrate at around 1/2 pi on Phi 2 and negative 1/2 pi on Phi 1.