Siegfried S. Hecker is a professor emeritus (research) in the Department of Management Science and Engineering and a senior fellow emeritus at the Freeman Spogli Institute for International Studies (FSI). He was co-director of CISAC from 2007-2012. From 1986 to 1997, Dr. Hecker served as the fifth Director of the Los Alamos National Laboratory. Dr. Hecker is an internationally recognized expert in plutonium science, global threat reduction, and nuclear security.

Dr. Hecker’s current research interests include nuclear nonproliferation and arms control, nuclear weapons policy, nuclear security, the safe and secure expansion of nuclear energy, and plutonium science. At the end of the Cold War, he has fostered cooperation with the Russian nuclear laboratories to secure and safeguard the vast stockpile of ex-Soviet fissile materials. In June 2016, the Los Alamos Historical Society published two volumes edited by Dr. Hecker. The works, titled Doomed to Cooperate, document the history of Russian-U.S. laboratory-to-laboratory cooperation since 1992.

Dr. Hecker’s research projects at CISAC focus on cooperation with young and senior nuclear professionals in Russia and China to reduce the risks of nuclear proliferation and nuclear terrorism worldwide, to avoid a return to a nuclear arms race, and to promote the safe and secure global expansion of nuclear power. He also continues to assess the technical and political challenges of nuclear North Korea and the nuclear aspirations of Iran.

Dr. Hecker joined Los Alamos National Laboratory as graduate research assistant and postdoctoral fellow before returning as technical staff member following a tenure at General Motors Research. He led the laboratory's Materials Science and Technology Division and Center for Materials Science before serving as laboratory director from 1986 through 1997, and senior fellow until July 2005.

Among his professional distinctions, Dr. Hecker is a member of the National Academy of Engineering; foreign member of the Russian Academy of Sciences; fellow of the TMS, or Minerals, Metallurgy and Materials Society; fellow of the American Society for Metals; fellow of the American Physical Society, honorary member of the American Ceramics Society; and fellow of the American Academy of Arts and Sciences.

His achievements have been recognized with the Presidential Enrico Fermi Award, the 2020 Building Bridges Award from the Pacific Century Institute, the 2018 National Engineering Award from the American Association of Engineering Societies, the 2017 American Nuclear Society Eisenhower Medal, the American Physical Society’s Leo Szilard Prize, the American Nuclear Society's Seaborg Medal, the Department of Energy's E.O. Lawrence Award, the Los Alamos National Laboratory Medal, among other awards including the Alumni Association Gold Medal and the Undergraduate Distinguished Alumni Award from Case Western Reserve University, where he earned his bachelor's, master's, and doctoral degrees in metallurgy.