After almost 15 years as Director of the Physics Division and 11 years as Associate Laboratory Director (ALD) for General Sciences, James Siegrist has announced that next summer he’ll be returning to a wide-ranging physics research program, which runs the gamut from building silicon detectors, to searching for extra dimensions of space, to monitoring the nuclear-fission fuel cycle. In addition, Siegrist will return to teaching at UC Berkeley, where he has been a professor in the Department of Physics since 1988. Siegrist will stay in his posts until July to allow time for a comprehensive search for his replacements.
“Under Jim Siegrist’s direction the Lab’s General Sciences have prospered in fruitful and often unexpected directions, and he leaves us a vibrant and very successful Physics Division at the top of its form,” said Lab Director Paul Alivisatos. “More discoveries are sure to emerge when he returns to his own research – and as a former division director, he will continue to be one of my most trusted advisors.”
Berkeley Lab has been a world leader in physics since it was established by Ernest Lawrence in 1931 to exploit the invention of the cyclotron. During Siegrist’s tenure as Physics Division Director, beginning in 1996, and ALD since 1999, the Lab has been at the forefront of particle physics, nuclear physics, and cosmology, playing leading roles in conceiving, designing, and building the experiments that have transformed our view of the world.
In 1998 the Supernova Cosmology Project based here announced that the universe is expanding at an accelerating rate, due to what would soon be called dark energy. Under Siegrist’s leadership, the study of dark energy has grown to include new supernova studies and new research methods, including baryon acoustic oscillation and weak gravitational lensing, plus continuing work toward a dark energy space satellite. In 2006 Berkeley Lab’s preeminence in cosmology was recognized when George Smoot won the Nobel Prize for his studies of the cosmic microwave background.
In high-energy physics, Berkeley Lab played a leading role in the development of the BaBar experiment at SLAC, conceived by former Berkeley Lab Deputy Director Pier Oddone. The Lab group contributed to the construction of BaBar’s components and the analysis of its data, which confirmed the Cabibbo-Kobayashi-Maskawa picture of charge-parity violation and won Nobel Prizes for two of its authors. Siegrist maintained Berkeley Lab’s leading positions in the DZero and CDF experiments at Fermilab’s Tevatron, which discovered the top quark. Himself a CDF collaborator for over twenty years, Siegrist contributed to the development of hardware, software, and data analysis for the CDF experiment as part of his own research. During Siegrist’s term Berkeley Lab physicists and engineers took the lead in developing and fabricating the 80-million-channel pixel detector of the Large Hadron Collider’s ATLAS experiment, of which Siegrist is a member; the Lab plays a principal role in ATLAS instrumentation and physics. One descendant of the Lab’s particle physics detectors is its unique, fully depleted, red-sensitive astronomical CCD. In DOE reviews, the Lab has ranked highest in designing detectors for high energy physics and astrophysics.
In neutrino physics, Siegrist brought together the Physics, Nuclear Science, and Engineering Divisions to pursue the phenomenon of neutrino oscillation. Reactor experiments at KamLAND in Japan helped solve the so-called missing-solar-neutrino question, and the Lab led in the design and construction of the Daya Bay Reactor Neutrino Experiment in China. Siegrist has championed the Deep Underground Science and Engineering Laboratory (DUSEL), led by UC Berkeley, to convert the Homestake Mine in South Dakota to the world’s deepest underground laboratory for investigating neutrinos, searching for dark matter, and performing a host of other scientific experiments in fields such as carbon sequestration.
In photon science, the Accelerator and Fusion Research and Engineering Divisions are helping to design a next generation light source that will revolutionize studies in materials, chemistry, and biology.
Siegrist is a Fellow of the American Physical Society, the author of over 250 scientific publications, and member or chair of numerous professional review committees, steering committees, and advisory groups in the field of physics. He received his B.S. in physics summa cum laude with special honors as well as a B.A. in mathematics from the University of Texas at Austin, and received his Ph.D. from Stanford University.
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