DOE Physicists at Work
Profiles of representative DOE-sponsored physicists
doing research at universities and national laboratories
Compiled by the Office of Scientific and Technical Information
Probing the limits of her world - that's what drives Brenna Flaugher, scientist with Fermi National Accelerator Laboratory.
Not only has Dr. Flaugher searched for the smallest constituents of matter, she has attempted to measure the properties of the largest structures of the universe. She has smashed protons together inside an accelerator to see what holds quarks - the tiny building blocks of matter - together. She has also observed the vast galaxies in an effort to unveil the mysteries of dark matter and dark energy. And she currently manages a project to build the largest CCD camera in the world (CCD, or charge-coupled device, cameras are similar to, but much more sensitive than, typical digital cameras).
"My interest in physics is driven by a desire to understand the world around us," says Dr. Flaugher. "My goal is to gain a better understanding of how our universe evolved from the time of the Big Bang, when everything was compressed into a dense homogeneous mixture of very hot gas and particles, to the universe we see today which is not homogenous at all; the stars and galaxies and galaxy clusters are all separated by lots and lots of empty space."
As a graduate student at Rutgers, The State University of New Jersey, Dr. Flaugher chose the field of experimental High Energy Physics. "This was probing the limits of our understanding by creating and studying the smallest fundamental constituents of nature," says Dr. Flaugher.
In her early career, Dr. Flaugher worked on a high energy physics experiment in which protons and anti-protons were smashed together at the highest energy possible at the time inside an accelerator. The idea was to study the forces that hold the quarks inside the protons together. "One of the most exciting projects I worked on was to determine if the quarks and anti-quarks inside the protons and anti-protons are made of smaller particles," says Dr. Flaugher. "Although all the current data indicates that quarks are the smallest constituents of matter, there is a possibility that they are made of particles so small we have not been able to see them." Dr. Flaugher's group found that if the smaller particles exist, their size is less than 10-16 cm .
Recently, she has moved into the fields of particle astrophysics and cosmology, where, by observing galaxies and galaxy clusters she hopes to begin to understand the dominant constituents of the universe, dark energy and dark matter. These are thought to comprise about 95 percent of the total energy density of the universe, yet they are little understood.
"I am working on a new project that will measure the properties of the largest structures in the universe," says Dr. Flaugher. That project is part of a new effort which studies the connections between particle physics, astrophysics and cosmology. "We know that the familiar components of the universe: neutrinos, quarks, hydrogen, helium, and stars all combine to make up only about five percent of the total energy density of the universe," says Dr. Flaugher. "The rest is in what we call dark matter (about 25 percent) and dark energy (about 70 percent).
Dark energy is gravitationally repulsive, and is thought to be responsible for the observation that the expansion of the universe is accelerating. "We study the effects of dark energy and dark matter by measuring the expansion rate of the universe and the rate at which stars, galaxies and galaxy clusters are formed," says Dr. Flaugher.
Dr. Flaugher is currently working on a project called the Dark Energy Survey, which will entail measuring 300 million galaxies and 30,000 galaxy clusters. "To make these measurements we will build the largest CCD camera in world," says Dr. Flaugher, who is project manager for building the camera, which will have 62 CCDs and approximately 500 megapixels.
"For comparison, the Sloan Digital Sky Survey camera has about 120 megapixels," says Dr. Flaugher. "With this camera we will take images of about 15 percent of the sky over a period of 5 years. The images we collect will allow us to take the next step towards understanding the nature of dark matter and dark energy."
Dr. Flaugher was born in Nashville, Tennessee and grew up in Princeton, New Jersey. She attended Bates College in Lewiston, Maine, graduating with a BS in Physics.
Her hobbies include biking (road and mountain), hiking, and occasional canoe trips to the Boundary Waters of Northern Minnesota".
Dr. Flaugher’s articles accessed via OSTI:
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