Cryocoolers are enabling new frontiers in cooling technology. As the demand grows for low-temperature electronics, sensors, and scientific instruments, cryocoolers have become indispensable tools for reaching freeze and near-absolute zero operating environments. Here we explore the evolving technology behind these cooling devices and highlight some of their innovative applications.
Types of Cryocoolers
There are several types of cryocoolers, each suited to different cooling ranges and payload capacities. The most common types include Stirling cryocoolers, pulse tube cryocoolers, Joule-Thomson cryocoolers, and Gifford-McMahon cryocoolers.
Stirling cryocoolers work by compressing and expanding helium gas via pistons in discrete cycles. They offer robust cooling from around 80 K down to 20 K with significant cooling powers from 10 watts to kilowatts. This flexibility makes them well-suited for applications like infrared imaging systems, superconducting electronics, and scientific experiments.
Pulse tube Cryocooler operate on a similar compression-expansion cycle as Stirling coolers but use specialized valves and tubes to deliver the working gas oscillations. They provide lower vibration levels than Stirling coolers and can reach temperatures from around 30 K down to 4 K with cooling powers from milliwatts to tens of watts. This has enabled new classes of infrared and superconducting devices.
Joule-Thomson cryocoolers leverage the Joule-Thomson effect where compressed gases expand and cool without changing phases. They are simple and reliable, offering cooling from around 80 K to 20 K with watt-level capacities. This has found use in applications like infrared cameras and space technology components requiring minimal vibration.
Gifford-McMahon cryocoolers utilize reciprocating displacers and heat exchangers in combination with gas compression and expansion. They offer excellent temperature control down to 4 K with cooling powers from milliwatts to a few watts. This precision has enabled systems like SQUID magnetometers and sensitive detectors in quantum computing and medical imaging.
Cooling Technologies Enable New Applications
These novel classes of cryocoolers have empowered new capabilities in fields like infrared sensing, superconductivity, medical therapies, and fundamental science. Stirling and pulse tube coolers have been particularly impactful due to their versatility.
Infrared cameras for night vision, thermal imaging, and process monitoring leverage room-temperature Stirling and pulse tube cryocoolers to maintain their focal plane arrays at temperatures around 80 K. This allows for higher resolution, lower cost detectors compared to older cryogen-cooled systems.
Superconducting electronics like radiofrequency filters, magnetometers, and quantum bits require temperatures below 10 K to function. Pulse tube and Gifford-McMahon cryocoolers offer packaged cooling solutions compatible with these instruments, enabling new classes of superconducting instruments and devices.
Magnetocryotherapy uses cryogen-free cryocoolers to precisely deliver targeted cooling to specific tumor sites, minimizing damage to surrounding healthy tissue. Systems incorporating Stirling and Joule-Thomson cryocoolers promise improved accessibility and reduced costs for this emerging cancer treatment technique.
Fundamental quantum and materials research relies on ever-improving control of temperature, magnetic fields, and quantum states down to millikelvin ranges. Joule-Thomson, Stirling, and Gifford-McMahon cryocoolers paired with dilution refrigerators now enable experiments exploring new states of matter as researchers approach absolute zero.
Continued Advancements Drive New Frontiers
Cryocooler technology continues to advance, with the next generation promising even greater temperatures, cooling powers, and applications. Hybridized systems combining different cryocooler technologies and improved regenerative materials are targeting below 1 K ranges.
Miniaturized micromachined cryocoolers less than a cubic centimeter in size could enable new classes of portable quantum and biomedical devices. Fault-tolerant cryocoolers with redundant components aim for enhanced lifetimes and reliability in long-duration space observatories and scientific missions.
As these evolving technologies push the boundaries of low-temperature cooling, they will continue unlocking new realms of science, technology, and discovery. Cryocoolers have transformed from laboratory curiosities just a few decades ago into indispensable enabling tools driving revolution in diverse fields. The coming years promise even more transformative applications that were once impossible to imagine.
Get more insights on Cryocooler
