Injecting Irradiation Samples with a Uniform Concentration of Helium Using Curium-244

A controlled-thickness alpha-particle source, made from ²⁴⁴Cm oxide, that can implant uniform concentrations of helium into the near-surface (0- to 4-µm) region of a solid material, has been developed. An analytical expression for the depth distribution of helium is in good agreement with helium measurements conducted on implanted nickel targets. The technique has particular application to experiments that seek to simulate neutron irradiation damage; it is simpler and less costly than other existing methods of helium injection.