 Segrè and his group of young physicists set up their experiment in an old Forest Service log cabin in Pajarito Canyon, about from the Technical Area, in order to minimize background radiation emanating for other research at the Los Alamos Laboratory.By August 1943, they had good values for all the elements tested except for plutonium, which they were unable to measure accurately enough because the only sample they had was five 20 μg samples created by the 60-inch cyclotron at Berkeley.They did observe that measurements taken at Los Alamos were greater than those made at Berkeley, which they attributed to cosmic rays, which are more numerous at Los Alamos, which is above sea level.