Awakening of the DRAGON: Commissioning of the DRAGON Recoil Separator Facility & First Studies on the 21Na(ρ,γ)22Mg Reaction

Sodium 21

The "Detector of Recoils And Gammas Of Nuclear reactions", DRAGON, is a new facility, especially designed to measure absolute cross sections of radiative proton- and alpha- capture reactions on radioactive nuclei of astrophysical interest. Located at the TRIUMF-ISAC radioactive ion beams laboratory in Vancouver, Canada, the DRAGON performs studies on reactions in inverse kinematics with ion beams in the mass range of 6 to 30 amu impinging on a gas target at energies of 0.15 to 1.5 MeV/u. A BGO detector array to tag the prompt gamma radiation emitted in a reaction surrounds the target, followed by a recoil mass separator and a double sided silicon strip detector which measures position and energy of the recoil at the final focus. Beam suppression of the order of 1011-1015 is needed to fully separate the readioactive beam ions from the much rarer reaction products. Systematic studies of varioius configurations using stable beams along with measurements of well-know resonance reactions were completed for the commissioning of the complete facility and the energy calibration of the new ISAC radioactive beam accelerator. Additionally, the first results of the scientific program, that has been launched with a study on the 21Na(ρ,γ)22Mg reaction at Ecm ≈ 821 keV, will be presented.

Author: Engel, S.