Photographic print, showing the formation of a new isotope of helium by bombarding heavy hydrogen with deuterons
Black and white photographic print, showing the formation of a new isotope of helium by bombarding heavy hydrogen with deuterons (from a photo lent by Prof. C.T.R. Wilson, F.R.S.), by Philip Ivor Dee at the Cavendish Laboratory, University of Cambridge, Cambridge, Cambridgeshire, England, 1937