The Use of Ion Accelerators and Synchrotron Radiation to Study the Interaction of Helium with Metals

A technique is described which examines the properties of helium trapped in bubbles in implanted metals. Helium implanted materials are characterized using resonant elastic proton backscattering and Transmission Electron Microscopy (T.E.M.). Spectroscopic measurements using synchrotron radiation in the far vacuum vutraviolet are then performed to examine the density sensitive optical absorption resulting from the 1S - 2P transition in the implanted helium. Experimental data for helium implanted aluminum thin films are presented which indicate atomic densities in small (50Å diameter) bubbles of the order of 1023 atoms cm-3.