Dark matter lights up the future
In the summer of 2023, five Fort Lewis College STEM students donned lab coats and dove into the mysteries of the universe at the Laboratori Nazionali del Gran Sasso nestled below—way below—the snowcapped Gran Sasso massif in the Abruzzo region of southern Italy. Established in 1985 under 4,600 feet of rock, the LNGS is the world’s largest underground research center. More than 700 scientists from around the globe seek these unique sheltered lab spaces for their low levels of natural radiation and cosmic-ray noise. The “quieter” environment amplifies their chances to discover rare neutrino and dark matter interactions.
“Dark matter has become a very popular STEM topic in recent years,” said Jade Martinez, a junior majoring in Computer Engineering with a minor in Mathematics. “I was part of another internship teaching students about particle physics, so I was very interested in the opportunity to expand my knowledge of quantum mechanics and experiments relating to particle physics.”
Because of the lab’s supreme bombardment-free conditions, the LNGS houses the world’s most advanced dark matter detector, known as the DarkSide-20K Detector. The dark matter detector requires low radioactive argon, all of which originates from a natural carbon dioxide reservoir in Doe Canyon, an hour west of Fort Lewis College. The extracted argon is shipped to Sardinia, Italy, for chemical purification before ending up at the LNGS to be used by scientists participating in the DarkSide Collaboration, a partnership of international labs and universities contributing to the DarkSide experiment.
While Princeton University serves as the DarkSide Collaboration’s lead institution in the U.S., FLC was pulled into the project in 2015 based on its proximity to the argon extraction site. As work at the extraction plant progressed, FLC Professor of Physics & Engineering Laurie Williams became the principal investigator for the Collaboration’s U.S. outreach. Part of her outreach includes connecting FLC students with the Princeton/Gran Sasso summer school program, which welcomes undergraduate students from around the globe to experience a day in the life of a professional scientist.
"This was an amazing opportunity to get more hands-on experience in a laboratory where cutting-edge experiments are being developed."
Victoria Nofchissey, a senior majoring in Physics
“Summer programs are designed to be introductions to what it is like to work in a specific field,” said Victoria Nofchissey, a member of the Diné Tribe and senior majoring in Physics. “The sooner you have a better idea of what that environment feels like, the easier it is to make academic choices that will guide you into a truly fulfilling career. I have always been passionate about particle physics and wanted to gain more insight into the physics that will shape the course of knowledge, so this was an amazing opportunity to get more hands-on experience in a laboratory where cutting-edge experiments are being developed.”
To the dark side
On a typical day, the students fueled up on caffe, cornetto, and fette biscottate at their hotel 30 minutes from the labs. They drove past mountains, rivers, and waterfalls before entering the tunnel to LNGS. Once inside the galleries, the students shadowed scientists in the physics, computer, mechanical, and electrical engineering sectors. Then they entered the Clean Room, home of the DarkSide-20K equipment.
“The Clean Room is where the photomultipliers are made and must be more sterile than a surgeon's room,” explained Shandyn Gee, a junior majoring in Engineering with an Environmental concentration.
Throughout their three-week internship, Gee and her colleagues received on-the-job training in the fabrication, testing, research, and development of DarkSide experiments.
“Seeing every department involved in making this [DarkSide] project happen is amazing,” said Elaina Saltclah, a member of the Diné Tribe and junior majoring in Physics with a minor in Mathematics. “When diving into the physics of each component, it is simply baffling to see the progress made because of the communication and troubleshooting that happens every day.”
Alumna Gwendolyn Jane Tsosie (Engineering, ’22) works at the Los Alamos National Laboratory as a post-baccalaureate in High Energy Nuclear Physics in the Nuclear and Particle Physics and Application Division. She was selected to participate in the 2023 LNGS summer program to enhance her understanding of particle physics and dark matter detector mechanics.
“Picking a favorite memory from the experience is difficult, but seeing the underground lab was probably the best; I learned the importance of that for dark matter and neutrino research and how hard it is to minimize noise in the data,” said Tsosie, a member of the Diné Tribe.
Shedding light on dark matter
The DarkSide-20K Detector seeks out rare signals of dark matter in the form of weakly interacting massive particles, called WIMPs. For science wimps (like most of us), what exactly is dark matter?
“If we consider all the ‘normal’ matter we know of in the universe—stars, gases, essentially all of the visible universe—it only accounts for about 5% of the matter and energy in the universe,” Williams explained. “Scientists believe that of the remaining 95%, 27% is dark matter, and roughly 68% is dark energy. It’s dark because it does not appear to interact as ‘normal’ matter does.”
Williams said the study of dark matter is not new; since the 1920s, astronomers have hypothesized that the universe must contain more matter than we can see because the gravitational forces at play in the universe appear stronger than the visible matter alone can account for.
“Several astronomical measurements have corroborated the existence of dark matter, leading to a worldwide effort to observe directly dark matter particle interactions with ordinary matter in extremely sensitive detectors, which would confirm its existence and shed light on its properties,” said the LNGS in a statement. “However, these interactions are so feeble that they have escaped direct detection up to this point, forcing scientists to build detectors that are more and more sensitive.”
After working alongside scientists in the Clean Room, the students spent an hour in afternoon lectures on cosmology, experimental and solid-state physics, semiconductor technology, electronics, and photo-electronics. They learned the basics of particle physics, data collection and materials selection, solar neutrinos, cosmic rays, past dark matter projects, the current DarkSide experiment, and fundamental theories, models, and ideas on quantum mechanics.
“I felt lost in the beginning,” Gee said. “I was definitely out of my comfort zone with no knowledge of particle physics and dark matter. At first, it felt lonely when everyone I was with knew what was going on, but then I would remind myself that it's okay that I don't know; I am here to learn.”
Gee wasn’t entirely lost; she had just taken an electric networks course at FLC, so she felt prepared for lessons around circuit boards.
“It was cool to see them use EAGLE [Easy Applicable Graphical Layout Editor] because I had to use the same program to make a [Printed Circuit Board] for my class,” Gee said. “I love seeing things I've learned in class used in the professional work environment.”
“Overall, this was an experience of a lifetime,” Saltclah added. "Summer programs are an amazing opportunity to see what happens in ‘the real world.’ Learning about particle physics and seeing a project of this magnitude in person was a dream come true.”
Back to normal matters
Besides wrapping their minds around the galaxy’s tiniest phenomena, the other obvious challenge for the travelers was navigating the language barrier.
“While at the lab, English was widely spoken,” Nofchissey said. “However, some things got lost in translation during lectures. Thankfully, the lecturers took the time to fully relay the information in a way we could understand, especially if we asked for clarification.”
“Several people told us that a lot of the scientific words are hard to translate because there are no equivalent words in other languages, so English it is,” Saltclah added. “Everyone we met was so nice and accommodating regardless of the language barrier. And hand gestures saved us.”
After a mind-blowing day of labs and lectures, the students unwound over cozy Abruzzese dinners featuring bruschetta, gnocchi, or arrosticini, every dish prepared with the Abruzzo region’s renowned olive oil.
“I found it fascinating that one of the traditional dishes was called arrosticini, which is skewered mutton,” Saltclah recalled. “Navajos love their mutton, too! It was fun to share with them that this is also one of our traditional foods, except that we down-skewer the meat.”
The students said another shared highlight was roaming to Rome to experience the art and architecture of the country’s most historic landmarks.
“Acknowledging other people's way of life and comparing that to your own can be very humbling and often promotes acceptance and empathy,” Martinez said. “To gain this kind of life experience as well as professional experience and knowledge is a great opportunity for undergraduates.”
"[This experience] made me feel more confident in my goal of becoming a physicist. My goal no longer feels like a pipedream, but attainable."
Elaina Saltclah, a junior majoring in Physics with a minor in Mathematics
“Dark matter: just hearing the words sounds so cool and enticing,” Saltclah said. “To get first-hand experience with subjects that interest you and to see the larger picture of what you want to do is something you simply cannot pass up. It made me feel more confident in my goal of becoming a physicist. My goal no longer feels like a pipedream, but attainable.”