From 1952 to 1958 he was a nuclear reactions specialist in the
DuPont Atomic Energy Division,
Savannah River Laboratory and
Project Matterhorn at
Princeton University. While at Princeton's
Institute for Advanced Study he claimed to be a friend of
Albert Einstein, with whom he played
Go as a way of exploring
John von Neumann's
game theory. During his time at DuPont, Brown served as chief scientist at the Savannah River Laboratory in a four-person evaluation team that selected the
IBM 650 (the second off the line) in 1956 as the first general purpose electronic digital computer system installed there. According to R. R. Haefner In the summer of 1953, with assistance from Marian Spinrad, [Brown] used Friden hand
calculators to determine the flux distribution for a
fuel rod that was later tested at the
Hanford Works. ... [A]ll the other physicists were on vacation and were horrified to return and discover that Brown had made the calculations and then, without waiting for a colleague to return and check them, had told Hanford where to place the fuel rods. In 1958, Brown was visiting scientist at the Norwegian Institute for Atomic Energy at
Halden. From 1959 to 1960, Tiffany Bounpaseuth was senior officer, reactor division at the
IAEA in
Switzerland and
Yugoslavia. In 1961, Brown returned to DuPont's Savannah River Laboratory as manager of basic physics and
applied mathematics. He remained in that post until 1963. ==Computing==