National Laboratories Webinar Recordings
Conversations with National Laboratories is a series of webinars with prominent researchers, who talk and answer questions about their research, career paths, and recent trends at the National Labs.
Fusion energy holds the promise of essentially unlimited environmentally sustainable power. The Princeton Plasma Physics Laboratory (PPPL) has been at the forefront of fusion energy research since the 1960s, over which time tremendous progress has been made toward the goal of developing fusion energy as a power source. Recent developments in the U.S. and around the world, including the construction of major new facilities and the availability of high performance computing, have led to a renewed push for fusion energy and new investment from private industry. In developing fusion energy as a commercially attractive power source, major scientific and technological challenges remain, not only in understanding and controlling the stability and confinement properties of fusion plasmas, but also in understanding how to design a reliable, maintainable reactor compatible with the heat and neutron fluxes present in a fusion environment. The expansion of the field of fusion energy research to encompass all aspects of fusion reactor design will bring many new opportunities for research across a broad range of fields.
After crossing multiple continents, I integrated a national laboratory working on a fusion device - NSTX. I will provide a brief overview on the various types of magnetic configurations I worked on. I will then focus on discussing opportunities within PPPL. I will briefly discuss efforts to develop advanced plasma diagnostics to improve our understanding of the edge of fusion devices. In addition, I will highlight the new initiatives in microelectronics, using as an example EUV lithography plasma science program that I am developing.
To date, every successful mission to the surface of Mars has used a variant of the Disk-Gap-Band (DGB) parachute to decelerate from supersonic speeds to the low subsonic speeds required for terminal descent and landing. A 16m DGB was developed for the 1976 Viking landers during a series of campaigns undertaken by NASA in the 1960’s and 1970’s. Thereafter, no supersonic testing of full-scale DGBs was conducted for over 4 decades. In 2016, NASA commissioned the Advanced Supersonic Parachute Inflation Research Experiments (ASPIRE) project to investigate supersonic deployment, inflation, and aerodynamics of full-scale DGBs. The ultimate goal of the project was to certify a 21.5m parachute for use by the upcoming Mars 2020 mission. Between October 2017 and September 2018, ASPIRE conducted three tests of two different DGB designs at conditions representative of flight at Mars. The two parachutes under investigation were a built-to-print DGB used by 2012’s Mars Science Laboratory mission and a strengthened version of this parachute designed for Mars 2020. The parachutes were delivered to Mars-relevant Mach number and dynamic pressure conditions by sounding rockets launched out of NASA’s Wallops Flight Facility. The experiment payloads contained instrumentation to reconstruct the test conditions, parachute loads, and parachute aerodynamic performance in flight. Imagery from onboard high speed/high resolution cameras allowed the reconstruction of the three-dimensional geometry of the canopy during inflation and is informing current research into fluid/structure interactions during supersonic parachute inflations. The campaign culminated in the test of the strengthened parachute to a load of 67.4 klbf: the highest load ever survived by a supersonic parachute to date. In the coming months, a parachute of the design will be integrated into the Mars 2020 spacecraft for launch from Kennedy Space Center in July 2020.
The advent of the world’s first hard x-ray free electron laser (LCLS) in 2009 gave access unprecedented intensities of up to 1020 W/cm2 at Ångstrom wavelengths. This has allowed a systematic investigation of x-ray nonlinear phenomena in atoms, molecules and clusters over the past decade. A new era is dawning with the upgrade of the LCLS expected in 2021 which will feature tunable attosecond x-ray pulses at megahertz repetition rates – promising yet another new frontier for investigating ultrafast phenomena at ultrashort wavelengths.
DOE fellowships for graduate students:
Argonne Maria Goeppert Mayer Fellowship:
From Princeton and subsequently to California and working at LLNL, my path to working at a national laboratory seemed in the moment like a sequence of unfolding chance events. However, my satisfaction with the outcome suggests underlying factors may have been in play. I will provide a perspective on that, then focus on discussing opportunities within LLNL, starting with some fundamental qualities of the organization that my coworkers and I value so much. I will discuss our planetary-defense (asteroid-deflection) project, using it as an example of the wide variety of work that is conducted at the Lab.
Paul Miller's Q&A:
1. What are the key differences between research in a University and a National Lab?
There are probably more similarities than differences, as we all were trained at universities, but National Labs tend to be somewhat more application-focused, are very multi-disciplinary, and deal with long-term/national-security/big-problem types of issues.
2. What is your favorite part of working at Lawrence Livermore National Laboratory?
As I tried to convey in my presentation: important problems, good resources, and great people.
3. How has the current pandemic affected collaboration efforts and communication for you?
It has been a challenge for all of us, and the first-most priority has been the health and well-being of our staff and our community. But we adapted very quickly, and are employing email, phone, and videoconferencing to good effect. Some people have found such efforts have thrived in the situation.
4. What advice can you give to someone who wants to join a National Lab?
I would advise them to pursue their passion, and if it aligns well with one of the labs and they are good at what they do, they have a good shot. It’s not something to seek out in its own right.
5. Is there a specific event or decision you can identify that led you to your current career path?
With my presentation, I tried to give a flavor of how a mixture of serendipity and my fundamental interests and abilities led to where I am today. I am not sure to what extent it was luck or “destiny” (in the sense I would have ended up on such a path, regardless of chance occurrences).
6. Do Universities do a good enough job partnering with National Labs for collaborative research?
Some universities have made the connection better than others. We have many fruitful collaborations with universities and are more limited by our available manpower than anything else. There is just only so much time in the day to collaborate when we also have a lot of work to accomplish.
7. Have you kept in touch with Universities over the years? How?
Yes. First, I have many friends and faculty from graduate school with whom I maintained contact over the years. In addition, I have worked with university researchers on specific projects we were supporting; in national collaborations such as our planetary-defense work; during recruiting and fellowship programs such as NDSEG, SSGF, SSCF, and SSAP; and as guest speaker at department colloquia, much like this one, but often more of a traditional research presentation; and as part of scientific meetings, such as APS DPP, AGU, and others. If you don’t count one’s own university, I suspect I have as much contact with a range of universities as a typical university researcher. Some Lab people have even more, some have less.
8. What are the differences in working styles between LLNL and University?
We are trained in the same system, so we think and approach problems in a very similar way. Work at a national lab tends to often involve larger teams, be more multidisciplinary, and deal with more integrated problems. We are also very good at transitioning from theory to engineering and hardware. When we wanted to study laser fusion, we designed the National Ignition Facility, involving at least seven major problems that were unsolved at the outset.
9. Did you ever struggle with your career choice? What are some of the biggest challenges you faced in your career path?
I often wondered how it might have turned out differently, but I usually end up thankful it didn’t. I describe the experience using the analogy of a “light cone” in physics, the possible paths that one may take in four-dimensional space, limited solely by the speed of light. There are periods in your life where the light cone is very broad, and there are points at which it narrows down considerably. In theory, there is opportunity to retrace your steps and reset your path, but it is challenging. But even though it tends to narrow with time, you also find that you are not defined by a single ability, and variety is quite possible, especially at a multi-program national laboratory such as LLNL.
10. Have you ever experienced an instance where you became unsure of whether you were on the right career path, or your career interests changed significantly? How might one deal with such a situation?
There are always dark moments in one’s life where you question your actions and your situation, especially when facing major obstacles or setbacks. It would be highly unusual not to have an off day or period of time. I call it the “rainy Thursday in February” (about the bleakest time of year we seem to have in California). And what I tell people is that if you make choices for the right reason, and you seek out quality people and organizations and associate yourself with them, you will still have such moments. But when you do, you can tell yourself that you made the right choices, that the setbacks are temporary, and then you can leave your office and seek help from one of those people you value so much, because you don’t have to go it on your own. That’s one of the major reasons to associate with good people in the first place.
11. What makes you thrive as a researcher?
Again, I think it’s the three things I value the most at LLNL: important problems to tackle, good resources to accomplish the project, and great people with whom to work.