A community of physics researchers

Lehigh’s Research Experiences for Undergraduates (REU) summer program for physics majors, Chloe Gooditis and Henry Koon are finding, is not a typical 9-to-5 job.

Gooditis, a senior at Goucher College in Maryland, is making glass samples doped with rare earth ions and using a femtosecond laser to write crystal lines inside the glass. She studies these crystal lines with a specially designed scanning microscope and evaluates the collected data to determine where and how the rare earth ions have inserted themselves into the crystal structure.

Gooditis is working with Volkmar Dierolf, the chair of the physics department, and graduate student Keith Veenhuizen. They hope to learn to manipulate the properties of the crystals and find applications for the crystals as optical materials in small scale photonics.

Koon, a senior at St. Olaf College in Minnesota, is working with Yong W. Kim, professor of physics, and graduate student Jesse Raffield on experiments that simulate microscopic thermal reactions. Using a container of ball bearings, the team has simulated an environment that represents the movement of metal atoms caused by thermal energy.

The researchers photograph the ball bearings in rapid succession as the container is shaking. They write algorithms that identify the center position and radius of each ball bearing and track them across the bursts of photos. In this way, they track distance traveled over time, giving an approximate velocity for each ball bearing. Plotting a graph of the velocities gives them an idea of the approximate thermal energy in the system. Close monitoring of the positions of the ball bearings allows them to determine if the simulated atoms are in a crystal formation.

Koon spends much of his time working on the algorithms that allow the computer to identify the circles and find the crystals. The goal of his research is to obtain information that will help explain why most solid matter is disordered and not crystalline. Such knowledge could find direct applications in the development of advanced materials.

Gooditis and Koon are two of the 22 students taking part in this summer’s REU program in the physics department. Eighteen of the students are from other colleges and universities, four are from Lehigh. Participants receive a stipend and free campus housing. Several hundred students nationwide applied for the program, which has received funding from the National Science Foundation for nearly 30 years.

The REU program is directed by Dierolf and physics professors A. Peet Hickman and M. Virginia McSwain, with McSwain leading the effort.

In addition to doing research with a Lehigh faculty member and graduate student, REU students live, work and explore together. Student researchers live in the same residence hall where they take part in social activities and can form friendships. Activities include dancing lessons in Allentown and trips to New York City and Washington, D.C.

“This has been a good learning experience,” says Koon. “It feels like we are much more independent than we are in my school.”

For Gooditis, the opportunity to take part in Lehigh’s REU program was too good to pass up. “I just wanted to come here because I really liked the school and the research sounded interesting.”

The grad student benefit

Coming from four-year schools, Gooditis and Koons both say they appreciate the chance to work with graduate students.

“My school is really tiny and we do not have graduate students,” says Gooditis. “It has been exciting to see how large the program is here and how much variation there is between projects. It is so interesting to see how much research is going on in this one place.

“Veenhuizen is a really great teacher. At first, I felt a little disappointed working under a graduate student, but it turned out to be even better than working under a professor. I’m getting a full experience of what graduate school will be like.”

Koon says he has taken advantage of Raffield’s expertise in programming.

“My graduate student [Raffield] is a master programmer, and he has been teaching me how to program in Java. It is really exciting because I feel that I have the power to do anything at my fingertips. He has really opened up a whole new world for me with programming.

“It has been interesting seeing a community that builds itself around graduate students.”

A full menu of research opportunities

When they arrive at Lehigh, REU students choose a research project from among a variety of fields. These include atomic, molecular and plasma physics; biophysics; condensed matter physics; photonics and nonlinear optics; and statistical physics.

“It is better to come here with a bit more knowledge in the field of physics,” says Koon. “They have no expectations of you coming in. They ask, ‘What are you comfortable doing? How can you help out?’, which is great for any age level, but in terms of feeling useful, it is better to come here later in your college career.”

REU students gain practical research skills as well as a deeper understanding of physics.

“I’m excited because I’m involved in the process of making the samples,” says Gooditis. “You get to weigh out the powder and melt it. It is really interesting to see the making of the samples we study.”

Gooditis participated in a research program at Goucher last summer, but Lehigh’s REU helped her gain independence.

“Last summer we got our samples from somewhere else. It has been really interesting to be part of every step of the process. I feel that I could probably be left alone to do it now. I’ve learned so much.”

For Gooditis and Koon, the study of physics represents not only the desire to create, but also to discover.

“I really like inventing things,” said Koon. “I went into the physics program thinking that it would help me with my projects, and it has been extremely interesting along the way. It is really exciting to know that the universe is way more complicated then we could ever wrap our head around. I love physics because it shows me just how much we don’t know.”

For Gooditis, the opportunity to continue learning is the greatest selling point.

“There is always going to be something to learn. Physics is one of the best tools to do that.”


Story by Samuel Quier