Leona Woods Leona Woods Leona Harriet Woods (August 9, 1919 – November 10, 1986), later known as Leona Woods Marshall and Leona Woods Marshall Libby, was an American physicist who helped build the first nuclear reactor and the first atomic bomb. At age 23, she was the youngest and only female member of the team which built and experimented with the world's first nuclear reactor (then called a "pile"), Chicago Pile-1, in a project led by her mentor Enrico Fermi. In particular, Woods was instrumental in the construction and then utilization of geiger counters for analysis during experimentation. She was the only
TOPAZ nuclear reactor TOPAZ nuclear reactor The TOPAZ nuclear reactor is a lightweight nuclear reactor developed for long term space use by the Soviet Union. Cooled by liquid metal, it uses a high-temperature moderator containing hydrogen and highly enriched fuel and produces electricity using a thermionic converter. In initial discussions, it was unclear that TOPAZ and the somewhat similar YENISEI reactors were different systems, and when the existence of the two Russian thermionic reactors became generally known, US personnel began referring to TOPAZ as TOPAZ-I and YENISEI as TOPAZ-II. The first thermionic converter reactors were discussed by scientists at the Los Alamos Scientific