Preparation and characterisation of an 39Ar sample and study of the 39Ar(nth,α)36S reaction.

The 39Ar(nth,α)36S reaction has been studied for the first time. A sample containing 2.85×1014 39Ar atoms was produced at the ISOLDE facility at CERN. The number of 39Ar atoms in the layer was determined by measuring the 39Ar β-activity using a primary standardisation method. Subsequently, the sample was irradiated with thermal neutrons at the High Flux Reactor of the Institut Laue–Langevin. An upper limit of 0.29b was obtained for the 39Ar(nth,α)36S reaction cross-section. [Copyright &y& Elsevier]