Reducing a university's helium footprint
Loomis Lab’s Liquid Helium Facility team’s recycling efforts conserve a precious resource while supporting leading-edge research
Jennie Z. Rose
for Illinois Physics
Illinois Physics Professor Jeff Filippini and his research group in the Loomis Laboratory of Physics develop astronomical instruments that observe faint light from the early universe. The instruments are mounted to massive helium balloons and launched from Antarctica. His team uses the observations collected in this way to shed new light on the universe’s history and the fundamental physics at work within it.
“Our observations are made at millimeter and sub-millimeter wavelengths—in between traditional radio astronomy and infrared astronomy,” Filippini explains.
The work in Filippini’s lab needs very cold temperatures that can be achieved only using liquid helium.
“This work requires sensitive superconducting detectors, cooled to a fraction of a degree above absolute zero, to reduce instrument noise,” he says. “Most of our instruments are launched on stratospheric balloons, where a heavy, power-hungry mechanical cooler is impractical. We use liquid helium to cool our balloon-borne instruments. We use smaller laboratory cryostats for pre-flight testing and technology development.”
Filippini’s team—like many other research groups on campus—orders liquid helium from the Helium Liquefier Facility on the first floor of Loomis Lab. Built in 1958 to support expanding research efforts in what was then called solid state physics—now known as condensed matter physics—the liquefier has since expanded its client base to include researchers across the sciences on the UIUC campus. Liquid helium has also become essential to chemical and biomedical sciences, as a cooling agent for superconducting magnets in magnetic resonance imaging (MRI) and nuclear magnetic resonance (NMR) spectroscopy.
Filippini points out that in recent years, some applications requiring helium cryogenics have transitioned to mechanical cryocoolers having a closed-circuit configuration using high-pressure gas. But liquid helium is still irreplaceable in many applications, where the complexity, mass, vibration, and electrical-power needs of a cryocooler are impractical.
Filippini doesn’t take for granted the access his lab has to this critical resource.
“Helium is an irreplaceable and non-renewable resource,” he comments. “We obtain helium as a byproduct of drilling for natural gas. It slowly accumulates in porous rock formations over geological time scales as a byproduct of radioactive decay. Once released to the air, however, helium escapes to space—we don’t get it back. It’s imperative that we steward our supply carefully.”
The flow of liquid helium out of the liquefier plant was interrupted during the last global helium shortage in 2012 and 2013. Massive price hikes and delivery delays threatened research progress. as many UIUC researchers were faced with what some referred to as a “trilemma”: pay high prices, shut down facilities temporarily, or find a substitute for helium. Research budgets were strained to cover increased costs, if helium could be delivered at all.
Illinois Physics research engineer Eric Thorsland checks on the compressors installed in the basement of Loomis Lab.
Illinois Physics cryogenics programmer Nikki Colton watches as undergraduate student worker Anna Przybyl solders.
Illinois Physics graduate student Rong Nie stings a helium dewar in the Filippini lab.
Illinois Physics cryogenics technician Kelly Sturdyvin works on the machinery in the liquefier plant.
Photos by L. Brian Stauffer, University of Illinois Urbana-Champaign
At that time, Illinois Physics researchers were recycling about half the helium being ordered in-house, thanks to a recovery pipeline system that had been installed throughout the Frederick Seitz Materials Research Laboratory and Loomis Lab in 2007. But the pressure was on to do better. Jerry Cook, then the facilities manager at Loomis Lab who oversaw operations at the liquefier plant, reached out to other universities having liquefiers, to get help improving the UIUC plant’s recycling and efficiency.
In 2014, the Helium Liquefier team was given the go-ahead to extend recycling efforts to buildings beyond Loomis Lab, under the supervision of Illinois Physics research engineer Eric Thorsland. Now, a helium return pipeline runs from both the Nuclear Physics Laboratory (NPL) and the Chemistry and Life Sciences Laboratory (CLSL) to the liquefier plant. A recovery system to handle the increased recycling load was installed in the basement of Loomis.
Before this effort, Thorsland had already installed a basic, stand-alone helium recycling system at NPL, under his own initiative.
Thorsland notes, “The inspiration to build the NPL stand-alone system came from need and from the reality that we were letting all the helium used at NPL into the atmosphere, and it was unrecoverable. This was not acceptable to me, and I wanted to recover the helium gas for sustainability reasons as well as to be eligible for the recovery credit given to labs already on the system in Loomis.”
It wasn’t long afterward that then–Head of Department and Professor Dale Van Harlingen tapped Thorsland to begin the multi-phase process of expanding the Loomis Lab recovery system beyond the Physics complex.
Thorsland worked with a team of facilities staff and faculty to plan, design and execute the project. In 2017, 1750 feet of long underground recovery line was run to CLSL. A team at Illinois Chemistry worked to connect its three facilities, while Thorsland worked with Illinois Chemistry Professor Dean Olsen—who uses helium for his own research—on the main collection system in CLSL. Another 10,000 feet of underground small-bore medium pressure line was installed through the steam distribution tunnels under Green Street and Goodwin Avenue in 2020, connecting the pipeline to NPL.
In 2017, Illinois Physics cryogenics programmer Nikki Colton, an alumna of the department who began working at the liquefier as a student worker, started installing a digital helium-recovery monitoring system, instrumenting diaphragm gas meters with credit-card-sized Raspberry Pi computers to collect data. This effort increased the efficiency of the total system by identifying the location of leaks, which were quickly repaired.
Since that time, Colton has worked with Thorsland to continually refine the helium-recovery monitoring system, installing Raspberry Pis on humidity sensors and rewriting the computer programs, originally written in LabVIEW code, in Python. Colton worked with Illinois Physics undergraduate student Anna Przybyl, a student worker in the liquefier plant, to develop the new code.
Thorsland notes, “The addition of Nikki Colton to the team and her work on adding electronic monitoring of the recovery metering system for data collection has been a major tool in improving the recovery rate. We have real-time data on gas flow, humidity, and pressure in the system, and this has helped significantly in our ability to quickly troubleshoot loss and contamination and to swiftly take action. Nikki’s help in mentoring our student workers and her effort to document the recovery system have been a key part of the operation and contributed to our ability to make the system sustainable.”
More efficiencies in helium production and recycling have been introduced through maintenance and upgrades to the plant itself. Most recently, these have been under the direction of cryogenics technician Kelly Sturdyvin, who took over day-to-day operations in the plant in 2019. Sturdyvin’s mechanical intuition—as he calls it, “keeping an ear for the liquifier machine”—keeps the Liquid Helium Facility’s cryogenic compressors and operations running optimally, with outputs above manufacturer’s recommendations. Sturdyvin says the ongoing rapport with technicians and engineers at other liquefier plants using recovery systems has been critical to his success.
The liquefier team has been supported in their stewarding efforts by a faculty-staff task force appointed in 2019 by Illinois Physics Head and Professor Matthias Grosse Perdekamp. The task force—initially led by Illinois Physics Professor Liang Yang and including Filippini and Illinois Physics Professor Vidya Madhavan, Cook (then the facilities manager), Sturdyvin (then the assistant facilities manager), Thorsland, and Illinois Physics business manager Steve Knell—reviewed many years of budget details and consulted with representatives of comparable liquefier plants at several other universities to make recommendations to the department, including increased staffing, hardware upgrades, and an annual audit of the plant.
Filippini led the team that conducted the first annual audit.
“The first audit found that work had begun on a number of our recommendations,” notes Filippini. “With the help of additional staffing, the team has carried out a program of improvements to the recovery system, as well as reviews of the lab practices of each user group. These have led to a much more leak-tight system, improving efficiency and reducing costs. The largest capital investments were delayed during the COVID-19 crisis but are still being pursued.”
Currently, the liquefier team is continuing this program of support and upgrades to the facility and its services. Looking forward, the task force is also studying the feasibility of expanding helium services and recovery systems to more users on and off campus.
A new timeline written by Illinois Physics cryogenics programmer Nikki Colton details the Helium Liquefier facility improvements: https://physics.illinois.edu/research/facilities/helium-liquefier-timeline.
Historical data analysis on several dozen recovery meters, two humidity sensors, and two pressure transducers is made available online to the campus community here: https://heliumrecovery.web.illinois.edu/.
Ballooning research in the Filippini group is supported by NASA’s Science Mission Directorate through the SPIDER (grants NNX17AC55G, 80NSSC21K1986) and TIM (grant 80NSSC19K1242) programs.