The latest Decadal Study of Plasma Science, conducted by the National Academies of Science, Engineering and Medicine (NASEM), calls for collaboration among federal agencies to realize the full benefits of a field that runs the gamut from the cosmological scale—shedding light on the early days of the universe—to the nanoscale, enabling the etching of semiconductors into ever smaller circuits.
The field of plasma science is interdisciplinary by nature, and so fundamental research in plasma science applies to many other areas of science and technology. Unfortunately applications of plasmas sometimes fall into the cracks between disciplines and between the missions of federal agencies. Kushner discussed what plasma has to offer—including opportunities for technologies that sterilize air and surfaces or provide green electricity—and how an upcoming wave of retirements is a challenge, but could also provide an opportunity to renew the field.
Why is plasma science so important?
Plasma science and plasma-enabled technologies have revolutionized modern society. This impact starts at the very largest scale of the universe, attempting to answer, for example, where magnetic fields come from, how galaxies are formed, and what produced the conditions that enable life on Earth.
At the other extreme, plasma science is fundamental to the manufacture of semiconductor devices. Plasmas are used to make the chips that power Zoom calls, the internet, all computers and other electronic and microelectronic devices. And it will lead to the development of new technologies ranging from better, faster electronics to new modes of cancer therapy and food safety, from producing carbon-free electricity using fusion power to compact particle accelerators and electrical propulsion for spacecraft. Plasma science touches all of these disciplines.
What’s the biggest takeaway from the Decadal Study?
One of the leading recommendations of the study is that federal agencies should collaborate on interdisciplinary initiatives that enable translational research, research that takes fundamental concepts and moves them towards applications and technology.
We are good about funding fundamental plasma science through agencies such as the Department of Energy, National Science Foundation, Department of Defense and NASA—though more funding is needed in basic science and for new facilities. To take that next step and make better use of the basic research, the more fundamentally oriented agencies need to collaborate with agencies that could benefit from plasma-based technologies such as the National Institutes of Health, the Environmental Protection Agency, US Department of Agriculture and the Food and Drug Administration.
If we linked those agencies through inter-agency collaborations, we would enable translational research in a continuous way, starting with the fundamentals and adapting those fundamentals into technologies. With more feedback between the research on fundamentals and the final applications, the transition of plasma science to societal benefit is more rapid and more focused.
Have we missed any opportunities due to the gap between fundamentals and applications?
During the current pandemic, there has been a rush to produce new tools for sterilizing surfaces and even the air we breathe. For at least the last 10 years, there have been many proposals that have been written precisely in this area: plasma sterilization of surfaces, using plasmas inside heating, cooling and ventilation systems to kill viruses, or to combat antimicrobial resistance. This area has been poorly funded because it finds itself in the gap between plasma physics and medicine, or plasma physics and biotechnology, and there are few mechanisms to fund that type of interdisciplinary work in the U.S.
So we now have a pandemic. Had we been more open to and more serious about this type of interdisciplinary research, we might have had more tools that could have been used to mitigate it. We would have been able to, for example, use plasma to sterilize personal protective equipment, to sterilize masks, to clean the inside of airplanes and to clean high-touch surfaces. Instead, there are few examples of these technologies having been commercialized. Most are still under development.
There are several activities at the University of Michigan to develop and commercialize these plasma-sterilization technologies. Professor Herek Clack in civil and environmental engineering is developing a plasma air sterilization system. Professor John Foster in nuclear engineering and radiological science and Professor Mirko Gamba, in aerospace engineering are developing a plasma surface sterilization device. How is the U.S. doing in relation to other countries?
Ten years ago, the U.S. was close to being the leader in nearly every subfield of plasma physics. However, the rest of the world is quickly catching up and in some cases outpacing the U.S. due to their focus on interdisciplinary and collaborative research, as well as the construction of midscale and large-scale facilities in Asia and Europe. This includes major new fusion facilities in Germany, Japan, Korea, China and the UK.
The largest collaborative activity in the world in plasma physics is the international effort to build a fusion reactor in France, called ITER. Although the U.S. is now a strong partner in ITER, during the past 10 years the support has been less consistent, at a time when few major facilities were being built in the U.S. You can only go so far in your leadership of the field if you are not building major facilities or consistently participating as an extremely strong partner in international collaborations.
In certain areas of plasma science, the U.S. is still clearly in the lead. The University of Michigan is heavily involved in several of these areas. For example, professors Carolyn Kuranz and Ryan McBride in the Department of Nuclear Engineering and Radiological Sciences are critical contributors to the field of high energy density physics, performing experiments here at U-M and at world-leading facilities at national laboratories.
Professors Karl Krushelnick and Alec Thomas are leading the development of a new laser facility at Michigan, called ZEUS, that will be one of the world’s most powerful lasers to study laser-plasma interactions. Professor Justin Kasper and colleagues in the Department of Climate and Space Sciences and Engineering are international leaders in the investigation of space plasmas and have several experiments on the Parker Solar Probe, a space mission to explore the sun’s corona and solar wind. This is a snapshot, rather than an exhaustive list, of leading plasma work at U-M.
It’s not necessary for the U.S. to dominate plasma physics as we have in past years; however, the U.S. should be influential on the world stage in determining the direction of the discipline. In the absence of new investments in people and facilities, we will become less so.
Will we have the people we need to take advantage of the science and technology opportunities described in the Decadal Study?
Plasma science is physics-based, but the applications can range from medicine to electronics and lighting, from welding to biotechnology. You will find faculty that investigate and use plasmas in almost every physical science and engineering department, including physics chemistry, geology, chemical engineering, nuclear engineering, mechanical engineering, bioengineering, civil engineering, electrical engineering, and materials science. They are also in life science departments because of the use of plasmas in cancer treatment, wound healing and biotechnology.
While the value of plasma science as a field of fundamental study and as an enabling technology for other fields is indisputable, there are no departments of plasma science at universities in the U.S. Plasma science is almost always a minority discipline within a department, and so it is rarely a priority for faculty hiring. It is rare to find more than a few faculty in any single department who are plasma-focused. Without coordination among departments and a commitment to the field, plasma science at US universities is at risk. And since the plasma science workforce, so critical to our economy and our national defense, is educated at our universities, that workforce is also at risk.
The plasma science workforce in academia, industry and national laboratories is facing a crisis. My generation, which makes up a significant fraction of the workforce, will retire in the next decade. The workforce needs to be renewed. At the same time, this need for renewal is also an opportunity. Plasma science is one of the least diverse disciplines within physics, even though we have made sustained efforts toward rectifying the situation. The large amount of hiring that will need to be done over the next 10 years offers us the chance to diversify the field to better reflect the society it serves.
Read more about leading plasma science projects at Michigan
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The decadal study was funded by the National Science Foundation, Department of Energy, Office of Naval Research, and Air Force Office of Scientific Research. Along with his co-chair Gary Zank, a professor of space science at the University of Alabama in Huntsville, and other members of the study group, Kushner has presented before the National Science Foundation, Department of Energy, Department of Defense, the Science and Technology Committee staff of the House of Representatives and the Senate, the Office of Science and Technology Policy, and the Office of Management and Budget.