Editing Frederick Reines (section)

== Los Alamos Laboratory ==
[[File:Reines-frederick.jpg|thumb|upright=0.7|Frederick Reines Los Alamos badge]]
[[File:Greenhouse Dog 001.jpg|thumb|right|[[Operation Greenhouse]] &ndash; [[Operation Greenhouse#Dog|Dog shot]]]]
In 1944 [[Richard Feynman]] recruited Reines to work in the Theoretical Division at the [[Manhattan Project]]'s [[Los Alamos Laboratory]], where he would remain for the next fifteen years.<ref name=Autobiography/> He joined Feynman's T-4 (Diffusion Problems) Group, which was part of [[Hans Bethe]]'s T (Theoretical) Division. [[Diffusion]] was an important aspect of [[critical mass]] calculations.<ref name = "NAS"/> In June 1946, he became a group leader, heading the T-1 (Theory of Dragon) Group. An outgrowth of the "[[Demon core#Second incident|tickling the Dragon's tail]]" experiment, the Dragon was a machine that could attain a critical state for short bursts of time, which could be used as a research tool or power source.{{sfn|Truslow|Smith|1961|pp=56-59}}

Reines participated in a number of [[nuclear test]]s, and writing reports on their results. These included [[Operation Crossroads]] at [[Bikini Atoll]] in 1946, [[Operation Sandstone]] at [[Eniwetok Atoll]] in 1948, and [[Operation Ranger]] and [[Operation Buster–Jangle]] at the [[Nevada Test Site]]. In 1951 he was the director of [[Operation Greenhouse]] series of [[nuclear tests]] in the Pacific. This saw the first American tests of [[boosted fission weapon]]s, an important step towards [[thermonuclear weapon]]s. He studied the effects of nuclear blasts, and co-authored a paper with [[John von Neumann]] on Mach stem formation, an important aspect of an air [[blast wave]].<ref name = "NAS"/><ref name=Autobiography/>

In spite or perhaps because of his role in these nuclear tests, Reines was concerned about the dangers of radioactive pollution from atmospheric nuclear tests, and became an advocate of [[underground nuclear testing]]. In the wake of the [[Sputnik crisis]], he participated in [[John Archibald Wheeler]]'s Project 137, which evolved into [[JASON (advisory group)|JASON]]. He was also a delegate at the [[Atoms for Peace]] Conference in Geneva in 1958.<ref name = "NAS"/><ref name=Autobiography/>