He participated in the Alsos Mission and at the end of the war rounded up German atomic scientists to keep them out of the Soviet Union .
The Alsos Mission conducted a series of operations with the intent to place all uranium in Europe into Allied hands .
He participated in the Alsos Mission , which conducted a series of operations with the intent to place all uranium in Europe into Allied hands , and at the end of the war rounded up German atomic scientists to keep them out of the Soviet Union .