Mentors Key to Student's Physics Research
When she was a junior in high school, Terri Poxon-Pearson, BS physics ’13, almost dropped her physics class. Twice.
“Things I thought were really basic were much more complicated, and I really like figuring out things that I can’t understand,” she says. “So I kept working at it, and at a certain point it just clicked. It didn’t get easier; I just found joy in figuring it out.”
Poxon-Pearson is currently working on her AU capstone in nuclear physics at the University of Maryland, following an intensive summer research project through a National Science Foundation program at the University of Notre Dame.
For 10 weeks, she worked closely with an advisor, a nuclear astrophysicist, studying a certain kind of nuclear reaction that occurs inside stars. “In order for atoms to fuse, they have to get really close together,” she explains. “Because all the protons repel each other, you have to smash them together really fast. This [creates] a lot of energy. Although stars are really hot, these reactions don’t actually happen that often. It’s really hard to measure how often it happens because it’s so rare.”
The research focused on this type of carbon fusion because it could be the reaction that fuels the weak s-process, a nuclear process in stars responsible for creating many heavy elements.
Among the many learning experiences afforded her through the program, Poxon-Pearson had the opportunity to run the particle accelerator at Notre Dame to measure the rate of this carbon reaction.
She presented her research at the fall 2012 meeting of the American Physical Society Division of Nuclear Physics in California.
At the University of Maryland, Poxon-Pearson is working with physics professor Carter Hall to identify a rare nuclear reaction, which, if found, would challenge the current understanding of particle physics. (The reaction is so rare that there can be almost no radioactive background in the detector.)
She is conducting research to determine whether Cobalt-60 is a significant possible source of background radioactivity. Materials in these experiments are selected for their natural low radioactivity. The detector she worked with was mostly made of copper.
“The particular copper was extracted and then machined in France,” she says. “The copper spent 20 days at sea level while it was rolled and processed and then 45 days at sea level while it traveled by boat between France and the U.S.
In that time, something remarkable happens: the low background material that left France is now more radioactive. This is because at sea level, without hundreds of feet of shielding, cosmic rays are constantly bombarding the material. Some of these rays react with the copper, and Cobalt-60, a radioactive material, is formed.”
Poxon-Pearson says her research experience has taught her that “you learn as you go. You don’t necessarily know what you’re doing all the time, but there are people there to help you learn as you’re doing it.”
It’s also given her a direction and defined her passion for particle physics. She would like to land a job with a large research component. “I have caught the research bug,” she admits.
What she loves most about research is when all of the hard work comes together. A researcher can do a lot of work, she says, before really understanding what the work means. “At a certain point, it all begins to fit together and you can really understand why you are doing whatever it is you are doing,” she says. “It is a rewarding feeling.”
AU physics professor Ulysses J. Sofia, who mentored Poxon-Pearson in the past, also sees research in her future. “I would be surprised if Terri didn’t end up in a job where research plays a significant role,” he says. “She’s a natural.”
The two worked together on a project to calibrate data for a French satellite that observes the sun to study its effects on global climate change. “The breadth of Terri’s research experiences to date is exceptional,” Sofia says. “It’s extremely rare in physics for an undergraduate student to work on three different projects with three different mentors who are at three different universities.”