19th International Cryocooler Conference

A group of 180 researchers and engineers from 12 countries gathered in San Diego June 20-23 for the 19th International Cryocooler Conference (ICC19), coordinated by the NASA Jet Propulsion Laboratory (JPL) and held at the Town and Country Resort and Convention Center.

The conference included a combination of 80 oral and poster presentations over the course of three days. Presentation topics included cryocooler modeling and analysis, cryocooler control electronics, large-scale cryocooler applications as well as cryocooler miniaturization, laboratory and aerospace applications.

On June 19, CSA hosted “Foundations of Cryocoolers,” its daylong short course designed to provide attendees with an understanding of cryocooler fundamentals and a description of how these principles are used in various types of gas-cycle cryocoolers to achieve temperatures from about 2 K to 150 K. Dr. Ray Radebaugh, consultant to the Applied Chemicals and Materials Division at NIST Boulder and a world-renowned expert in the field of cryogenics, taught the course together with Prof. Marcel ter Brake, a noted leader in the cryogenics field who is on the Faculty of Science and Technology, University of Twente, the Netherlands.

Reggie Little, from Iris Technology, was one of the course attendees. Like many in the cryogenics community he got involved in the industry because there was an on-the-job need. “But I didn’t know anything about what a cryocooler was, how it works or the different types, and so that’s why I attended the short course,” he says. “And now, after eight hours, I pretty much have the background and understanding of what’s going on. Now it all makes sense [and] I’m a happy person. It’s just a good program to get into, a really good course.”

Kelsey McCusker, a thermal engineer at Northrop Grumman and one of CSA’s 2016 Young Faces in Cryogenics, agrees. “There’s a lot of trial and error [in research fields] so it’s really nice to be able to come in here and get a lot of really condensed, useful information to eliminate a lot of the mistakes we could have potentially made in the future,” she says. “And, I like that [Ray] attaches a lot of it to the theory because then I’m able to really look at all the different cryocoolers and understand why one is better at a certain temperature or why another is better with a certain cooling capacity. And I think breaking it down like this is really useful.”

Radebaugh says teaching the course has been rewarding for him, especially when he is able to watch individuals new to the field develop into top researchers. “I see people come to the class who are maybe just starting in the field and then a few years later at the cryocooler conference they are presenting papers with some new ideas,” he says. “I’m learning from them in the process…so, it’s very rewarding to me.”

Through the 20 years that he has taught the course, Radebaugh says the biggest changes he’s seen have been in space applications, and indeed, the aerospace community has traditionally organized the conference. This year’s conference included a strong focus on space cryocoolers, detailed by Peter Shirron in his column of page 22 of this issue. The column includes a performance summary for long-life cryocoolers provided by JPL’s Ron Ross.

“We’ve got two or three coolers in orbit running 24/7 for 18 years,” Ross says. And there are “over 30 coolers up there now with over 10 years of continuous operation.”

Ross attended his first conference in 1988, chaired in 1994 and has worked extensively over the years to help distribute the papers presented at the conference. For some time the conference worked with various publishing houses, but in 2006 Ross helped start ICC Press, an in-house publishing company that now provides the papers in open access.

Ross says the open access is “terribly important” for the community. “The whole rate at which cryocoolers are advancing is very dependent on how quickly you can get the word out,” he says. “I’m still embarrassed with our situation to some extent with the period we were with the New York publishing houses because all of those papers are there but they charge you $30 apiece to look at them. It totally inhibits people being able to browse through the library of the old papers and pick up the technology.”

The conference provided attendees this year with digital copies of the peer reviewed papers. They will also be available on the ICC website and published in Cryocoolers 19, a hard bound proceedings book distributed to conference attendees via mail later this year and thereafter available to order from Amazon.com in early 2017.

The volume will include a paper from Alan Caughley, technology group manager at Callaghan Innovation, whose presentation on a new range of large pulse tube cryocoolers (see page 11) opened the conference. “I had one person collar me almost immediately afterwards,” he says. “And quite a few people have come up to talk about it. It’s been good. Well worthwhile. A lot of people are interested in the machine itself and the utility of the machine…It’s not one of the old things being refined more; this is something new.” He says that coming to ICC is essential for companies such as Callaghan that operate in the more remote areas of the world. “We don’t have that community in New Zealand, so I’ve got to come and talk to all the people here.”

One thing New Zealand does have, however, is a large community of whales. And attendees learned all about them from a special whale exhibit during the conference banquet held Wednesday evening at the San Diego Natural History Museum. The Del Lago Trio (a cello, flute and woodwind ensemble) provided relaxing background music for the evening.

After the conference concluded, a group of 50 interested attendees enjoyed a private tour of the world headquarters of Quantum Design, Inc. (CSA CSM), a manufacturer of cryogen-free measurement systems.

ICC19 was chaired by JPL’s Dean Johnson and co-chaired by Jose Rodriguez and Sidney Yuan of JPL and Aerospace Corporation respectively. Carl Kirkconnell from West Coast Solutions and Mark Zagarola of Creare LLC (CSA CSM) served as program chairs. Zagarola’s team presented a recuperator at ICC19, discussed on page 12, and the company will host ICC20 in 2018. “Creare is extremely excited and honored to host the 20th International Cryocooler Conference,” says Zagarola. “We look forward to welcoming the community to picturesque and historic New England in June of 2018.”