Study of the gas target density profile for the reaction 22Ne(α,n)25Mg

The 22Ne(α,n)25Mg nuclear reaction is an important neutron source, via s-process, and its rate also plays a role in type one-A supernovae. The LUNA Collaboration, using the Bellotti Ion Beam Facility, installed at the National Gran Sasso Laboratory (LNGS), is studying this reaction in the framework of ERC-Sarting Grant SHADES. The main goals are the measurement of the 22Ne(α,n)25Mg cross section in the low-energy range 600−800 keV and the redetermination of the 702 keV resonance energy and strength. This measurement is realized by bombarding a 22Ne gas with an high intense α beam. The windowless gas target is realized by three differential pumping stages and it must be characterized in terms of beam heating. In this contribution we will present the measurements of the density profile of the gas target through the 20Ne(p,γ)21Na reaction.