NIF and JLF User Groups Push HED Science Forward During Pandemic

February 25, 2021

LLNL Laser Safety Officer Jamie King (third from left) conducts a virtual tour of NIF during the 2021 meeting of the NIF and Jupiter Laser Facility user groups.

Leaders of the National Ignition Facility (NIF) and Jupiter Laser Facility (JLF) user groups at their annual meeting praised NIF and JLF staffs for keeping high energy density (HED) science experiments on track over the past year, overcoming the many challenges of the COVID-19 pandemic.

The coordination, planning, and assistance that went into those experiments made the lead scientists for those experimental campaigns feel like “happy campers,” said NIF User Group Executive Committee Chairman Petros Tzeferacos of the University of Rochester’s Laboratory for Laser Energetics.

“The level of commitment to Discovery Science is noteworthy,” Tzeferacos said. “Everyone went above and beyond and bent over backwards to make this happen.”

Tzeferacos spoke to an audience of about 265 attendees during the annual two-day user group meeting, which this year was conducted virtually through the online app Zoom. The meeting brings together scientists and researchers from both inside and outside of the Lab who conduct basic science experiments at NIF, using the world’s largest and most energetic laser, and the Janus, Titan, and COMET laser platforms operated by the Physical and Life Sciences Directorate’s Jupiter Laser Facility. The NIF User Office, on behalf of the user groups, organized the all-online format.

The groups learned more about the most recently selected crop of NIF Discovery Science Program campaigns, took virtual NIF tours, and received an update on the progress of a major JLF refurbishment project.

About 8 percent of approximately 400 NIF experiments each year are set aside for the Discovery Science Program. That schedule was affected this past March when regional and statewide shelter-in-place orders because of the pandemic halted NIF’s experiments through the end of April.

Still, the affected Discovery Science campaigns were only delayed, not cancelled, as NIF restarted operations under new COVID-19 safety protocols (see “COVID-19 Safety Measures Allowed NIF to Resume Vital Experiments”). NIF also implemented a process that allows the principal investigators (PIs) to completely run their experiments remotely without having to physically come to the facility (see “Remote NIF Control Software Updates Lead to Less Stress, More Efficiency”).

Since NIF experiments are normally scheduled at all hours of the day, including the wee hours of the morning, the PIs appreciated having a fully remote option.

“All interactions take place online,” Tzeferacos said. “Now you can do NIF shots in your pajamas at home.”

New Members, New Ideas

The meeting began with a farewell address from LLNL Director Bill Goldstein, who is retiring after 36 years at the Lab, seven as director. Goldstein said he was heartened to see the user group continually bringing in new members and new ideas to NIF and JLF, which he called “the Pantheon of DOE (Department of Energy) user facilities.”

Those facilities are “able to do unique things because of the commitment and the talent and the trust of this group,” Goldstein said. “Please keep doing what you’re doing at JLF and the NIF. It’s really, really important and its really, really exciting.”

Kim Budil, who will succeed Goldstein as Lab director, noted she began her Lab career working on short-pulse lasers and still considers herself “a card-carrying high energy density scientist.”

“This really is the golden age of this type of experimental science,” Budil said. “Not a week goes by that someone doesn’t bring me a new result or an amazing new diagnostic technique that far outstrips anything I could have imagined when I was doing this type of work. And that to me is really exciting.

“Experimental science doesn’t exist simply to validate what we know,” Budil added. “It really is to teach us new things and to help us probe the frontiers of science.”

SLAC National Accelerator Laboratory research associate Benjamin Ofori-Okai discusses his experiment during a virtual meeting of the JLF User Group.

JLF User Group Chair Christine Krauland of General Atomics said she appreciated the Lab’s quest “to push the broader HED science physics community and to train students. We really are grateful for this facility existing and can’t exist without this great user community.”

Last year was supposed to be the last full year of a four-year effort to refurbish JLF, which had included components from previous LLNL lasers that were up to 50 years old. The COVID-19 restrictions did push that schedule back about six months, but the project—which will give the facility new laser capabilities and state-of-the art automated control systems—is back on track to allow outside researchers access by next February, said JLF Director Bob Cauble. He expects to issue calls for new experimental proposals in about six months.

General Atomics provided support for the meeting’s annual Poster Session; the poster contest winner in the postdoctoral category was Edward Hansen of the University of Rochester for “Implicit Anisotropic Magnetic Resistivity in the FLASH Code,” a high-performance computing application code used for physics problems.

In the graduate student category, John Ryan Peterson of SLAC National Accelerator Laboratory and Stanford University took first place for “Magnetic Field Amplification by a Nonlinear Electron Streaming Instability.” Second place went to Michael Wadas of the University of Michigan for his poster, “Analysis of Unsteady Strong Shock Waves with Applications to Hydrodynamic Instability Growth.”

NIF-JLF 2021 poster contest winners: From left, Michael Wadas, University of Michigan, John Ryan Peterson, SLAC National Accelerator Laboratory and Stanford University, and Edward Hansen, University of Rochester.

The latest group of future Discovery Science projects selected spans galaxy clusters, turbulent combustion, star-formation dynamics, accreting black holes, white-dwarf envelopes, cosmic-ray generation, magnetic-field destruction, and exotic beam-generation mechanisms. The NIF and JLF members heard presentations from:

• Didier Saumon, Los Alamos National Laboratory, on “Scratching Below the Surface of White Dwarf Stars: EOS Measurements at Gbar (1 Gigabar=1 billion Earth atmospheres of pressure).”
• Seth Davidovits, LLNL, on “Laser Experiments on the Turbulent Formation of Stars.”
• Roberto Mancini, University of Nevada Reno, on “Achieving Iron Photoionization Equilibrium at NIF.”
• Federica Coppari, LLNL, on “The Structure of Superionic and Complex Water Ices at Terapascal (1 TPA=10 million atmospheres) Pressure.”
• Michael Paul, Hebrew University of Jerusalem, Racah Institute of Physics, on “Noble-Gas Accelerator Mass Spectrometry Platform at NIF for Nuclear Astrophysics.”

Commented NIF Director Doug Larson, “NIF is continuing to deliver for stewardship, producing stunning results, addressing important questions for stewardship, bringing the next generation of scientists along the way, and pursing the grand challenge of fusion ignition in the laboratory.”

—Benny Evangelista

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