  Helium implantation in surfaces is of interest for plasma facing materials
and other nuclear applications. Vanadium as both a representative bcc material
and a material relevant for fusion applications is implanted using a Helium ion
beam microscope, and the resulting swelling and nanomechanical properties are
quantified. These values are put in correlation to data obtained from micro
residual stress measurements using a focused ion beam based ring-core
technique. We found that the swelling measured is similar to literature values.
Further we are able to measure the surface stress caused by the implantation
and find it approaches the yield strength of the material at blistering doses.
The simple calculations performed in the present work, along with several
geometrical considerations deduced from experimental results confirm the
driving force for blister formation comes from bulging resulting mainly from
gas pressure buildup, rather than solely stress induced buckling.
