Circuits of Interest Led Engineering Intern to NIF&PS

When Lan Huse joined Columbia University’s formula-style car racing team last year, she worked on systems that ensured the electric vehicle’s high-voltage battery safely discharged into an electrical resistor when the car was shut down.

As it turned out, that experience directly translated to tasks Huse performed at LLNL this summer as an intern working with the NIF&PS Laser Systems Engineering & Operations (LASE) team. She took on a conceptual redesign to improve part of NIF’s high-voltage capacitors.

There is a big difference in scale: Columbia’s Formula Racing team builds one-passenger vehicles just slightly bigger than go-carts, while NIF’s massive capacitor system has some 7,680 flashlamps that can deliver nearly 330 million joules of electrical energy stored in 3,840 high-voltage capacitors.

In both cases, however, “the essential concept of using resistance to be able to manage high voltage over a capacitor is the exact same thing that I’m doing here, which was kind of coincidental,” Huse says.

She described the summer project as a way to improve NIF’s flashlamp testing facility “with a relay system that will allow the capacitors to dump their energy through a resistor and not the flashlamp, just in case you need to discharge them.”

The work she performed this year at Lab—where her mother had interned for two summers in the mid-1990s—could have longer-lasting impacts on NIF for years to come and demonstrates the real-world experience and immediate benefits a NIF&PS intern can have.

“This is for useful for us, and this is useful for her,” says Power Conditioning System engineer Bruno Le Galloudec, NIF’s Pulsed Power Group leader. “This is an old system. It’s so noisy and it scares you every time that you use it, and when you're working with high voltage, that's not something you want to hear. So, upgrading it is going to be way better.”

Huse is a sophomore electrical engineering major at Columbia in New York City, where she grew up. As a child, she had become familiar with science because her parents are both biologists, although she intended to become a linguistics major in college. She also did a biology internship studying a marine organism related to stem cell research at Stanford University two summers ago in Monterey, California.

But during her senior year in high school, an advanced physics class that included a unit in building electrical circuits for a radio sparked an interest in electronics. Another enjoyable college physics course led her to the Columbia Space Initiative, a space science and engineering club, where she joined a team designing printed circuit boards.

She also obtained a HAM radio license and joined the Columbia Formula Racing team, designing switch voltage regulators and printed circuit boards to test high-voltage systems, indicator lights, and relays.

“I really wanted to do hands-on stuff and use that creativity that is required of engineers,” Huse says. “That's what I like most because a lot of it is hands-on and doing all the dirty work yourself.”

Another topic of interest surfaced during that advanced physics class in 2022 when a classmate wrote a paper that put fusion energy “on our radar,” she says. “And then that winter, ignition happened.”

Huse mentioned that event to her mother, Kara Pham, who as a young biologist was an intern at LLNL in the 1990s. “She would tell me all about her days at Livermore,” Huse says. “She had a lot of fun here.”

One of the friends Pham met at the Lab was then-fellow intern Zhi Liao, who went on to become a Lab laser physicist and now serves as NIF & Photon Science workforce manager. Liao recalled that Pham rented a room from Liao’s mentor at the time, laser systems optical engineer Simon Cohen, “and we became friends and stayed in touch ever since.”

When Liao learned of Huse’s interest in a Lab internship, he told Le Galloudec of her work on high-voltage printed circuit boards. That brought to mind an idea Le Galloudec previously considered, to study the concept design for a new “dump” system to safely protect NIF’s high-voltage capacitor bank from excess electrical power when the bank is fully charged. The current capacitor bank’s technology stems from NIF’s processor, the 1980s-era Nova laser, and uses an air-controlled pneumatic system.

Le Galloudec wrote an internship proposal for Huse to study the concept of replacing those old systems with a modern high-voltage relay system tied into NIF’s newer computerized control systems.

The internship involved working with engineers from the control system, high-voltage, and pulse-power teams to design a PCB board that controls those relays and sends information back for viewing on NIF’s main control system. The project seemed a perfect fit for Huse.

“She’s super enthusiastic and she's very smart,” Le Galloudec says. “She’s very, very curious, very inquisitive. I think she had a blast because she has so many questions, she was interacting with everyone in the group.”

Le Galloudec also wanted to make sure Huse benefited from learning the rigors of what it takes to be an engineer from other engineers.

“To be an engineer,” he says, “it’s very important that when you design something, when you are part of the design team, that you have the system engineering concepts. You need to define who the stakeholders are and their expectations.”

And engineers, he says, must determine what it takes to “make sure that you're going to design something that the customer wants, and put together the documentation, the diagrams, all those things that go with projects.”

Huse noticed that for other interns, part of the job was “deciphering code that was written 10 or 20 years ago, and the people who created them aren’t here anymore.

“I've definitely realized the importance of documentation,” she says. “The engineering process has been a lot more formalized. The path is kind of strict, but it takes you through all the necessary steps to be able to make sure your project is reliable and something you’re proud of in the end.”

Another key lesson was to more fully understand how NIF operates.

“It’s really important to talk to the people around you and learn what they’re doing and learn how NIF works overall so that you can understand how your work fits into it,” Huse says. “Because otherwise, if you don't know what purpose your work has for the larger system, then sometimes it can feel pointless.”

Huse won a first place award in an Aug. 7 NIF&PS Summer Scholar Program poster symposium for “Implementation of Rose Relays in Flashlamp Testing Facility Capacitor Dump System” (see “Ignition Continues to Spark Interest in NIF&PS Intern Program”).

She also discovered a new pastime: Back in his intern days, Liao was introduced to soccer by his mentor Cohen, a tradition he passed down to Huse this summer through the Lab’s lunchtime recreational groups. “I’m having so much fun,” Huse says. “That’s like a big hobby that I want to take back to New York with me.”

Huse says her overall Lab experience is helping to affirm her choice of a career and that she would also like to return someday.

“My mom would always say that when finding a job, you need two things,” she says. “You need to be happy, and you need to help people. And I think I was trying to find that balance. But engineering’s pretty good with both of those.

“I really love it,” she says. “It took a while to find engineering. I went through basically all the careers possible before I figured this out, but I feel like this one will definitely stick because I feel like everyone in the field just loves it so much.”

More Information:

“Ignition Continues to Spark Interest in NIF&PS Intern Program,” NIF & Photon Science News, Oct. 2, 2024

“Livermore Lab Foundation Selects LLNL Fusion Fellows for 2024,” NIF & Photon Science News, Oct. 2, 2024

“LLLNL Intern Applies Lessons Learned from Home, Family,” NIF & Photon Science News, Sept. 4, 2024

“LLNL HBCU Week Showcases Lab Expertise, Culture, Work-Life Balance,” NIF & Photon Science News, Jan. 3, 2024

Follow us on X:@lasers_llnl