Choong-Shik Yoo provides technical and programmatic leadership in developing research programs aligned with programmatic objectives and mentoring the experimental scientists in the group. He has extensive research experience in high-pressure materials research and is an expert on high pressure and temperature technologies (diamond-anvil cell, shock-wave, laser-heating, cryogenic), various laser spectroscopic methods (linear, non-linear, time-resolved), synchrotron x-ray diffraction and spectroscopy, fast optics and electronics, and various in-situ materials characterization methods. Major accomplishments of his recent scientific research include discoveries of polymeric carbon dioxide, non-magnetic cobalt and new forms of carbon, many of which were published in scientific articles such as Science and PRL and also reported in popular presses like The New York Times, C&E News, and Oakland Tribune. Choong-Shik has been working at the Laboratory since 1989, after completing his Ph. D. at UCLA in 1986 and a three-year post-doctoral research position at Washington State University. He is a member of American Physical Society, American Chemical Society, American Geophysics Union, Materials Research Society, and Sigma Chi Honor Society.