Unlocking Cosmic Secrets: A Fellow’s Journey into High Energy Density Science
The universe holds mysteries that captivate and challenge scientists. But what if a fellowship could empower researchers to explore these enigmas? This is the story of Patricia Cho, a fellow at the High Energy Density Science (HEDS) Center, who is delving into the secrets of the cosmos and pushing the boundaries of our understanding.
The HEDS Center fellowship at LLNL is a catalyst for postdoctoral scientists to venture into uncharted territories of research. For Cho, an experimental physicist, this meant stepping beyond her Ph.D. focus and embracing the vast realm of laboratory astrophysics.
Iron’s Cosmic Puzzle
Cho’s journey began with a perplexing question: Why is there an abundance of iron in the swirling accretion disks around black holes? During her Ph.D. studies in astronomy, she aimed to unravel this mystery.
Accretion disks, spinning around black holes, are like cosmic whirlpools. But here’s where it gets intriguing: when modeling these disks, scientists need to add more iron than expected to match observations. And this isn’t just a quirk of one type of black hole…
“We see this iron overabundance in both stellar mass and supermassive black holes,” Cho explained, emphasizing the mystery. These black holes differ vastly in size and formation, making the consistent iron surplus even more puzzling.
Unraveling the Mystery
To solve this cosmic riddle, Cho ventured to Sandia National Laboratories’ Z machine. Her experiments aimed to recreate the conditions of black hole accretion disks in a lab, seeking evidence of the iron enigma. This foray into laboratory astrophysics laid the foundation for her future endeavors.
In 2024, Cho’s path led her to Livermore, where the HEDS fellowship supported her exploration of a new cosmic question.
The Sun’s Convection Conundrum
Cho’s research now focuses on opacity, a critical factor in understanding how radiation interacts with matter in astrophysical settings. “Opacity helps us build accurate models of star and galaxy formation, shaping our view of the universe’s history,” she said.
Her work is driven by a discrepancy between helioseismic measurements and stellar structure models in pinpointing the solar convection zone boundary, where energy transport mechanisms change. Below this boundary, radiation dominates, while above it, convection takes over.
The challenge? Helioseismology and stellar models disagree on the boundary’s location. Cho’s experiments at NIF aim to reconcile these differences, providing crucial data for accurate opacity measurements.
From Cosmic to Terrestrial
Cho’s research has also taken a terrestrial turn, with experiments that could have direct applications on Earth. This shift showcases the versatility of her work and its potential impact on our world.
Embracing New Frontiers
Cho’s curiosity led her to explore electron fast ignition (EFI), an innovative fusion energy concept. She collaborated on an experimental campaign in Paris, working on core diagnostics, including a titanium K alpha imager, to visualize electron collimation.
Back at Livermore, Cho continues her EFI research, refining experiments at the Jupiter Laser Facility. She attributes her ability to explore diverse topics to the HEDS fellowship and Livermore’s supportive environment for postdocs.
But here’s where it gets controversial: Are we truly understanding the universe’s mysteries, or are we merely scratching the surface? Cho’s work invites us to ponder the depth of our cosmic knowledge. What other secrets might the universe hold, waiting to be uncovered by curious minds like Cho’s?
Learn more about the fascinating world of HEDS and its impact on our understanding of the cosmos:
– NIF&PS Summer Scholar Program Celebrates a Record Year
– Researchers Use NIF for a Deep Dive into Red Dwarf Interiors
Follow the journey of discovery: @lasers_llnl