| 2001-present | Research Chemist and Research Associate (retired, on recall), Deputy
Director Emeritus University of California Energy Institute |
| 1983-present | Lecturer Department of Nuclear Engineering University of California, Berkeley |
| 1981-2001 | Research Chemist and Deputy Director University of California Energy Institute |
| 1978-1980 | Department Head Information and Data Analysis Department Lawrence Berkeley Laboratory |
| 1971-1978 | Senior Staff Member and Director, Isotopes Project Nuclear Science Division Lawrence Berkeley Laboratory |
| 1964-1971 | Staff Member, Isotopes Project Nuclear Chemistry Division Lawrence Berkeley Laboratory |
| 1961-1963 | Graduate Student Research Assistant Nuclear Chemistry Division Lawrence Berkeley Laboratory |
| 1960 (summer) | Student Research Assistant, Deuterium Biology Program Chemistry Division Argonne National Laboratory |