# Wayne State University QuarkNet Center

Submitted by kcecire

on Wednesday, July 3, 2013 - 09:24

The Wayne State University QuarkNet center, under mentors Rob Harr and Paul Karchin, has a strong program of research each summer. Detroit-area high school students team up with QuarkNet teachers to work with cosmic ray detectors and the e-Lab in their own projects. The Wayne State group also works with the Detriot Metropolitan Area Physics Teachers (DMAPT) to help tjem bring particle physics to the classroom and create opportunities for professional development. Wayne State is also involved in International Masterclasses each year, allowing students to be "particle physicists for a day".

### Description

Students and teachers studying cosmic ray, physicists and teachers collaborating, and more.

# QuarkNet at Wayne State University

# The Speed of Muons from Different Angles: Looking at a Different Angle

The Speed of Muons from Different Angles: Looking at a Different Angle

Subrai Burkhalter (Detroit School of the Arts), Rachel Kirichu (International Academy East)

Mike Niedballa (WSU)

Rob Harr (WSU)

The purpose of our research is to discover if muons being detected at different angles move at different speeds. This research is an addition to a previous Quarknet study of the same title to better confirm, or disprove, the former data. To do this we aligned four muon detectors (the farthest apart being 2.145 meters) and ran time of flight studies with a coincidence of four to determine the average speed of muons at different angles 15 degrees apart (starting from 15 degrees to the surface to 75 degrees to the surface).

We infer from our research that as the detectors angle was closer to the surface, the faster on average the muons were traveling. This is the exact opposite conclusion from the Quarknet study before us, therefore more studies are needed to confirm which conclusion is accurate.

# The Effect Of Sand On Muon Flux

**The Effect Of Sand On Muon Flux**

Kaitlyn Proffitt (Eisenhower High School/Utica Center for Mathematics, Science, and Technology), Khaliah Spoljaric (Robichaud High School)

Mike Niedballa (Wayne State)

Rob Harr (Wayne State)

The purpose of our research was to study the effect of different heights of sand on muon flux. We aimed to simulate the behavior of muons once they traveled below ground level. We started the study with four muon detector paddles. We placed paddles 1 and 2 stacked on top of each other on the top shelf of a 1.180 meter tall shelving unit. Paddles 3 and 4 were also stacked on top of each other and were placed on the ground directly beneath the first two paddles under the shelving unit. We ran seven trials, one trial without any sand bags between the muon paddles and six trials adding an additional bag of sand each time. The height of each bag of sand was an average of 0.100m. Flux was recorded at ten minute intervals. The trials would run for time periods varying in length from six hours to sixty-five hours, due to time constraints. For each trial, we ran a flux study, each with a coincidence level of four. Our data showed a negatively linear relationship between muon flux and height of sand with a line of best fit of y = -44.685x +199.9, showing that an increased height of sand does decrease muon flux. If our projection is correct, there would be no muon flux at a depth of approximately 4.5 meters below the surface. If sensitive scientific research or medical needs required an area free of cosmic radiation, creating a lab or office below this depth could be a solution, effectively shielding against muons. Further data collection would yield more accurate results.

# The Effect of Water Depth on Time of Flight of Cosmic Ray Muons

# The Effect of the Thickness of Aluminum on the Speed of Muons

**The Effect of the Thickness of Aluminum on the Speed of Muons**

Nathan Frazier (Cousino High School/ MMSTC), Seth Hall (International Academy of Macomb)

Mike Niedballa (Wayne State University)

Gil Paz (Wayne State University)

**Purpose**

The purpose of this experiment was to test the effect that different thicknesses of aluminum would play on the speed of muons. Prior experiments proved that with more aluminum shielding the flux of muons will decrease. Our experiment furthers this research. It is hypothesized that the thicker the aluminum is between the paddles, the slower the muons will travel.

**Method**

The method to this experiment is to run a time of flight study on the muons. The coincidence was set to two paddles one on top and one on the bottom (2.2 meters apart). First control data was collected without aluminum between the paddles. We then placed 77mm of aluminum between the paddles and collected data. Next 123mm, 225mm, and 300mm of aluminum were all placed between the paddles. Each collection of data was ran for at least 4 hours. The average time a muon was calculated given the certain amount of aluminum between the paddles. Our data from each thickness trial was graphed and a regression was fit to the data with the slope being the speed.

**Results**

Our data shows a direct relationship between the thickness of aluminum and the speed lost. There are some points that are far from the line but the r squared value is close to 1 so are data does fit the line of regression well.

**Meaning of Data**

Our data shows that there is a difference in speeds between the different thicknesses of aluminum because our p value of 0.0518 is so close to our alpha level of 0.05. Since we determined that there is a strong chance of the speeds being different, we ran some linear regression t-tests (one with the difference in speeds and one with the percent of the speed of light). The p-values for these two tests are both roughly 0.00674 which is less than the alpha level, so we can reject our null hypothesizes that there is no strong linear correlation. The slopes of these regression lines told us that, on average, for every millimeter of aluminum added the muons will slow 64525.5 m/s or 0.02% the speed of light. Since there was a difference in the speeds and it did follow a linear model, we accepted our hypothesis.

**Suggestions for further Research**

In future studies we can use bigger thicknesses to see if this linear trend continues and we can also try different materials to see if they slow down the muons at different rates.

# Measuring Muon Flux as a Dependent on Barometric Pressure

# The Effect of Aluminum Shielding on Cosmic Ray Muon Flux

**The Effect of Aluminum Shielding on Cosmic Ray Muon Flux**

Adam Ross (De La Salle Collegiate High School), Jill Schell (Macomb Mathematics Science Technology Center)

Mike Niedballa (Wayne State University)

Dr. Gil Paz (Wayne State University)

The experiment was performed to determine the effect of various thicknesses of aluminum as a shield against cosmic ray muons. This test added to and expanded on research done that shows the effect of other metals as shields against the same rays. This study was conducted using four cosmic ray muon detectors set up in pairs, with each pair one meter apart. Multiple trials were conducted, gradually increasing the amount of aluminum between the pairs of detectors. After running multiple tests, the value of the flux had a clear but small decrease as the thickness of aluminum was increased. Also, the amount of aluminum was shown to have a decreasing linear relationship with the muon flux. With the data that was collected, the researchers were able to conclude that the greater amount of aluminum present, the smaller the muon flux. This finding also leads to the conclusion that aluminum can act as a weak shield against the cosmic ray muons. This research could be furthered with greater quantities of aluminum to determine, with greater accuracy, when the flux would near zero. Also, this research, combined with outside research about the shielding effects of other materials and metals, could create a better understanding of the effect of density on muon shielding, and help better determine which material has the greatest shielding effect, and for what reasons shielding is effective.

# The Effect of Water Depth on Muon Flux

**The Effect of Water Depth on Muon Flux**

Grace Gutierrez (Roosevelt High School), Finsam Samson (Troy High School)

Mike Niedballa (Wayne State University)

Gil Paz (Wayne State University)

**Purpose**

This study was conducted to analyze the effect of water depth on muon flux. It built upon other research in this field, using larger scales of depth than was done in previous studies. Our hypothesis is that increasing the depth of the water that muons have to travel through will decrease the flux of the muons at the bottom, as the muons can be slowed and stopped by interacting with water molecules.

**Methods**

In this study, 3 large plastic bins with a maximum depth of 26 centimeters each were used. Four detector plates set in a column with a four-fold coincidence were used with these bins. The arrangement of these were as so (from top to bottom): plate, bin, plate, bin, plate, plate. Plateauing was conducted at first, and the four detector plates were calibrated accordingly. The study began with a control of 0 centimeter depth, and increased by 10 centimeters with every flux study conducted, until 70 centimeters. Two flux studies were run every day, with data collection running for at least 4 hours in each study.

**Results**

Our data shows an inverse relationship between muon flux and water depth. However, this relationship becomes unclear after .30 meters of water depth. The uncertainty is also graphed above. The depth of .40 meters had an uncertainty significantly larger than that of the other depths. One possible reason for this could be a power outage that occurred on the day that data was collected, as well as in subsequent days.

**Meaning of the Data**

The collected data does support our hypothesis. In the first half of the experiment, muon flux decreased as depth increased, with low uncertainties. However, high uncertainties in the latter half of the experiment led to unclear results beyond .40 meters of depth.

**Suggestions for Further Experimentation**

In future studies, efforts can be made to accurately collect the data from high values of depth. This is because it is unclear whether the relationship between muon flux and water depth is linear or exponential (decay). Additionally, other liquids could be tested as shielding to research the properties of substances that shield muons.

# The Speed of Muons from Different Angles

The Speed of Muons from Different Angles

Anna Citko (Groves High School), Genevieve Yarema (Grosse Pointe South High School)

Mike Niedballa (Wayne State University)

Gil Paz (Wayne State University)

Cosmic rays are particles (mostly protons) that come from space and are traveling near the speed of light. When these particles enter our atmosphere, they can collide with atmospheric gases and shatter into many other particles, including muons, the focus of our study. When the particle shatters, the products can go in all different directions. We wanted to figure out if muons coming down perpendicular to the surface of the earth maintain more of their speed than muons coming in at an angle. We tested this by placing 4 muon detector paddles in a telescope which we were able to tilt at different angles. We took data at at vertical, 45 degrees, and horizontal angles and used a time of flight study with a coincidence of 4 to determine the speed of the muons from each angle. We found that muons are coming in at a slower speed at an angle than they are vertically, but we were limited in how much data we were able to collect, so further studies may be needed.

# Lifetime of Muons and the Detector’s Orientation

Andrew Du (Cranbrook High), Mason Hinawi (Crestwood High)

Mike Niedballla (Wayne State University)

Gil Paz (Wayne State University)

The purpose of this lab is to investigate muons and find the best way to study muon lifetime with the Quarknet cosmic ray muon detector. We were specifically trying to determine which orientation would provide the most data in the least amount of time. There are three different orientations that we tested: lying flat horizontally, standing vertically on the long edge, and standing vertically on the short edge. We found substantial data correlating the position and amount of decays. Since our results show standing the detector up on its short edge allows for significant improvement this could be the new standard procedure for future QuarkNet students studying lifetime decay.