We have an opening in the Nuclear Security Physics Group for a Theoretical Physicist to work on developing new nuclear diagnostic capabilities and on problems related to the statistical theory of fission chains. This work will support the nation's ability to counter, respond to, and if necessary, mitigate a nuclear or radiological incident quickly. This critical mission is the responsibility of the U.S. Department of Energy, National Nuclear Security Administration's (DOE/NNSA) JTOT (Joint Technical Operation Team) Program--an agile, task-organized unit, ready to react at a moment's notice to support nuclear and radiological weapons of mass destruction incidents.This position will be filled at either level based on knowledge and related experience as