Research on ice: Spartan students help unlock cosmic mysteries in Antarctica

Alejandra Granados, a graduate student specializing in particle astrophysics, inspects a nearly completed digital optical module. Photo by Derrick L. Turner

Roughly a year from now, scientists at the IceCube Neutrino Observatory will begin deploying more than 400 multi-photomultiplier digital optical modules, or mDOMS, deep inside a 1 billion-ton block of ice at the South Pole as part of the IceCube Upgrade — a feat powered in part by the work of a team from Michigan State University.

The mDOMs are sensors that look like black and gold soccer balls from the future, and their job is to detect elusive neutrinos, which are invisible, nearly massless subatomic particles that have helped scientists understand some of the most fundamental questions in physics. This upgrade will bring neutrinos into sharper focus.

The MSU IceCube group is essential to the project. Of the 400-plus mDOMs being deployed — other units and calibration devices are also part of the upgrade — 205 of them will be manufactured and tested by a team of undergraduates, graduate students, engineers and postdoctoral students from MSU. Once their work is done, these sensors will be shipped nearly 9,160 miles from East Lansing to the South Pole.

 

“This is really important work,” says Emmett Krupczak, a National Science Foundation graduate research fellow and the project lead. MSU is making 205 sensors, and a lab in Germany is creating the rest. “Our undergraduate students are doing high-level technical work. Once these modules are in the ice, they’re not coming back — and MSU students are a pivotal part of making the IceCube Upgrade possible.”

Pablo Rizzo, a junior majoring in mechanical engineering, is one of 18 undergraduate students producing the sensors. He helps test completed sensors that have been placed in a dark freezer to mimic Antarctic conditions. “We’re very fortunate to be here at MSU where the leadership on this project is trusting us, especially as undergrads, and giving us this opportunity to work on IceCube,” he says. “Even if what we’re doing is a small drop in the bucket, it’s very satisfying to feel like the work you’re putting in is helping.”   

A cosmic collaboration of scientists

Emmett Krupczak, the project lead, inspects a yet-to-be completed digital optical module. Photo by Derrick L. Turner

The IceCube Neutrino Observatory is the first detector of its kind.  Although based at the South Pole, its research is led by the IceCube Collaboration, a global team of 350 physicists from 58 institutions in 14 countries. According to the group, “IceCube searches for nearly massless subatomic particles called neutrinos. These high-energy astronomical messengers provide information to probe the most violent astrophysical sources: events like exploding stars, gamma-ray bursts and cataclysmic phenomena involving black holes and neutron stars.”

The lead institution is the University of Wisconsin-Madison, and the National Science Foundation provided the primary funding, with assistance from partner funding agencies around the world.

The MSU IceCube group is one of the largest in the IceCube Collaboration, with six faculty members and numerous engineers, postdoctoral researchers, graduate students and undergraduates. The group grew when MSU was selected as one of two sites in the world that would produce and test the new mDOMs as part of the IceCube Upgrade.

Chris Ng (center), an engineer, speaks with students and researchers as they work on digital optical modules. Photo by Derrick L. Turner

Tyce DeYoung is a professor in the Department of Physics and Astronomy and head of the MSU IceCube research group. “Helping to construct the upgrade has given opportunities for MSU students and postdocs to get hands-on experience — always wearing gloves, of course — building, testing and calibrating cutting-edge high-energy physics sensors that will be contributing to scientific discoveries for years to come,” says DeYoung. “There are fewer and fewer places where students have the chance to work with hardware directly these days, so it’s been really exciting to have MSU be the center of so much of that work.”

MSU’s facility, located in the Biomedical and Physical Sciences Building on campus, underwent a readiness review by a national research center in Germany and other IceCube institutions, and began building the mDOMs in the spring of 2024.

Building the neutrino sensors of tomorrow

Each mDOM consists of 24 photomultiplier tubes that amplify faint light signals, several liters of silicone gel, three cameras, many LEDs, electronics and specially designed, 3D-printed support structures.

Erika Finley, a junior majoring in physics, pours gel into a digital optical module, a process that, including curing, takes eight hours. Photo by Derrick L. Turner

The undergraduates, graduate students, engineers and postdocs working on the mDOMs take on specific roles, whether pouring the silicone gel that will hold the photomultiplier tubes in place, connecting wires to their corresponding ports, performing electronic testing or sealing and installing a metal harness for deployment.

Erika Finley, a junior majoring in physics, is a gel specialist.During a physics class she was taking last spring, DeYoung mentioned the MSU IceCube group was looking for students to assist with the project. She jumped at the opportunity.

“At first, we all learned about the general production,” Finley says, “but once Emmett saw us getting into the groove of things, we started getting assigned production roles.” Finley was interested in working with the silicone gel right away and, after working on multiple mDOMs, has become somewhat of an expert. The process is long, taking about eight hours per gel pour, but Finley isn’t taking that time for granted.

“This is so much more than having experiment experience for my résumé,” Finley says. “Seeing how broad this project expands is so rewarding. This isn’t just some internship. These mDOMS are going to be in the ice detecting neutrinos for centuries.”

While the science is serious and the students are meticulous in their work, they make sure to have fun along the way. Early on, the team decided to name each of the 205 mDOMs after a Taylor Swift song.

A team effort that will leave a legacy

During the second week of November, the MSU IceCube group put finishing touches on assembling the final few mDOMs. Through December and into early 2025, the modules will be tested in the dark freezer and will go through optical testing with a laser before any final adjustments will be made. Then, in summer 2025, they will begin their journey to the South Pole and the IceCube Neutrino Observatory.

Numa Arif, a senior majoring in applied engineering sciences who plays a role in quality control for the project, works on a digital optical module. Photo by Derrick L. Turner

From there, they will be lowered into the 1 billion-ton block of ice. The modules that began their journey in East Lansing will offer readings of neutrinos that are two to three times more sensitive than the sensors that are currently embedded there.

Numa Arif, a senior majoring in applied engineering sciences, is thrilled to have been part of the current IceCube Upgrade. She helped craft the mDOMS and was also responsible for inventory and nonconforming materials. If a part was broken, she had to inform the correct people involved with IceCube and make sure that her team received replacement parts. And even though her work in the lab is winding down, she feels proud to have been a part of it.

“We all had to be in the right place at the right time for this to come together,” Arif says. “The IceCube Upgrade is a once-in-a-lifetime project and, for me, it was such a fulfilling experience.”

Learn more about the MSU IceCube group.

Hero image by Martin Wolf, IceCube/NSF