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Cryogenics

High cost and disruptions in helium supply make it difficult to carry out research at temperatures close to absolute zero

The liquefied from of the noble gas is used to cool magnetic resonance imaging machines, particle accelerators, and quantum computers

Helium used in the LHC particle accelerator

Maximilien Brice /CERN 

A severe global shortage of helium, the fourth since 2006, has seen helium prices doubling from early-decade levels. The international cost of a cubic meter (m3) of helium—about 1,000 liters—jumped from US$7 in 2021 to US$14 the following year. In Brazil, the price has soared to around R$190, three times what it costs in the US or Europe. Though recent months have seen a modest recovery in supply and some easing of prices, global supply constraints and increasing demand from applications in medical imaging, industrial processes, and scientific research suggest a continued surge in overall demand in the years ahead.

As a gas that is lighter than air and completely inert, helium is perhaps best known for its use in decorative balloons, weather balloons, and airships. However, helium’s most important uses leverage a unique property in its liquid phase. As the only element that does not solidify at temperatures approaching absolute zero (0 Kelvin or -273.15 °C) under standard pressure, liquid helium is essential in applications that require ultra-low temperatures. These range from magnetic resonance imaging (MRI) machines and particle accelerators to quantum computers and materials science research.

Helium is critical, for example, for research activities at the Solid State and Low-Temperature Laboratory at the University of São Paulo’s Institute of Physics (IF–USP). “When helium runs out, everything grinds to a halt. In 2009, we went an entire year without helium in the department, and no one could work. The following year, I wasn’t able to publish a single paper,” says Rafael Sá de Freitas, the lab’s lead physicist. His current research involves applying strong magnetic fields to materials to observe their behavior at near-zero temperatures—a line of inquiry that depends on reliable access to helium-based cryogenics. “My work is done at temperatures just 0.1 °C above absolute zero. Without helium, I can’t even reach 70 Kelvin,” explains Freitas, who managed to secure enough helium this year despite rising prices.

“We’re monitoring the helium supply closely and exploring alternatives, not only to mitigate rising costs but also to prepare for potential disruptions,” says Eduardo Granado, a physicist from the Gleb Wataghin Institute of Physics at the University of Campinas (IFGW-Unicamp). Granado, who studies quantum materials, also relies on cryogenic systems. “To manage impacts from rising helium prices on our low-temperature research, we’re prioritizing and sharing cooled equipment across different research groups.”

Helium is the second most abundant element in the universe after hydrogen, and is present in all stars. On Earth, however, it is found only in trace amounts within the atmosphere—just five helium molecules per million air molecules. Due to its lightness, helium readily escapes Earth’s gravitational pull and dissipates into space. Helium is also produced within the Earth’s crust through the radioactive decay of uranium and thorium and is typically extracted alongside natural gas as a byproduct of oil drilling. Annual production, around 170 million m3, is mostly confined to five countries—Qatar, the US, Algeria, Russia, and Canada—with distribution controlled by a few large multinational corporations. Around half of the helium extracted is lost during bottling and transport, making it even more expensive.

MRI machine relies on helium to functionSiemens Healthineers

The most recent helium shortage began in January 2022, when a major leak at the US Federal Helium Reserve in Amarillo, Texas, abruptly cut 10% of the global supply. The following month, Russia’s invasion of Ukraine disrupted natural gas production and, by extension, helium extraction. Additional factors compounded the crisis: four production facilities in Qatar went offline for scheduled maintenance, and Algeria opted to sell its natural gas directly to Europe rather than refining it to extract helium. These combined events tightened the helium market, which is only now starting to stabilize.

In Brazil, helium is even more costly due to logistical expenses. Data collected by IF-USP faculty show that the price of a cubic meter of helium has been rising since 2018. From R$31.4 in 2017, it doubled to R$68 in 2018, reached R$150 in 2019, and climbed to R$190 in early 2022, eventually peaking at R$495 in November of that year. Prices have since eased back, dropping to R$270 in October 2023 and reaching R$190 now in 2024.

One approach to reducing helium dependency is the adoption of “cryogen-free” systems. Despite the name, these devices use a small amount of liquid helium in a self-contained system. When the helium heats and evaporates, it is re-cooled and liquefied through a mechanical process. The Brazilian Center for Physics Research (CBPF) in Rio de Janeiro, for example, has ordered a cryogen-free system to reactivate six pieces of equipment that have been idle since last year due to helium shortages.

While cryogen-free systems are expensive and costly to maintain, they are a one-time investment that lessens the need for ongoing helium purchases. These systems are not without limitations, however. They generate vibrations that can make them unsuitable for some applications, such as quantum computing. They are also less suitable for systems exposed to very strong magnetic fields. “We would like to keep some basic equipment running on liquid helium, but that hasn’t been possible,” explains Magda Fontes of CBPF. Despite recent signs of market stabilization, international analysts predict that helium prices are unlikely to drop significantly in the coming years due to high demand.

The story above was published with the title “Weighed down by the helium crisis” in issue 344 of October/2024.

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