Richard Watts was a research assistant at the Chicago Met Lab and at Los Alamos during the Manhattan Project. He was present on December 2, 1942, when Chicago Pile-1 went critical. He recorded statistics of the experiment in his notebook, and when the pile went critical reportedly wrote, "We're cookin'!"
At Los Alamos, Watts led a team in the Electronics Group of the Physics Division. They developed a number of alpha-particle detectors--culminating in the portable "Pee Wee"--named for its mere nineteen pounds, to detect radioactivity in the work environment.