Peierls also became leader of T-1 ( Implosion ) Group , and so was responsible for the design of the explosive lenses used in the implosion-type nuclear weapon to focus an explosion onto a spherical shape . He sent regular reports to Chadwick , the head of the British Mission to the Manhattan Project , in Washington , DC . When Groves found out , he asked Peierls to send him reports too . Peierls was one of those present at the Trinity nuclear test on 16 July 1945 . He returned to England in January 1946 . For his services to the nuclear weapons project , he was appointed a Commander of the Order of the British Empire in the 1946 New Year Honours , and was awarded the US Medal of Freedom with Silver Palm in 1946
Medal of Freedom
Medal of Freedom (1945)
Rudolf Peierls