Level structure of Mg21: Nuclear and astrophysical implications
Resonant elastic scattering of a radioactive $^{20}\mathrm{Na}$ beam incident upon protons in a polyethylene target has been used to probe the level structure of $^{21}\mathrm{Mg}$ above the proton decay threshold. Three states have been observed, and their properties deduced through analysis based on the R-matrix formalism. The results improve and extend previous studies of this nucleus. An estimate of the $^{20}\mathrm{Na}$(p,\ensuremath{\gamma})$^{21}\mathrm{Mg}$ reaction rate, including these new data, suggests this reaction will not play a significant role in explosive hydrogen burning in astrophysical sites such as novae and x-ray bursts.
Charged-particle reaction studies for nuclear astrophysics
The TUDA and TACTIC facilities at TRIUMF provide versatile experimental capabilities for the study of astrophysically important reactions using both direct and indirect techniques. The present work will outline the research programme to date, describe the experimental facilities and discuss recent developments.
The REX-ISOLDE project
The Radioactive Beam Experiment REX-ISOLDE [1–3] is a pilot experiment at ISOLDE (CERN) testing the new concept of post acceleration of radioactive ion beams by using charge breeding of the ions in a high charge state ion source and the efficient acceleration of the highly charged ions in a short LINAC using modern ion accelerator structures. In order to prepare the ions for the experiments singly charged radioactive ions from the on-line mass separator ISOLDE will be cooled and bunched in a Penning trap, charge bred in an electron beam ion source (EBIS) and finally accelerated in the LINAC. The LINAC consists of a radiofrequency quadrupole (RFQ) accelerator, which accelerates the ions up to 0.3 MeV/u, an interdigital H-type (IH) structure with a final energy between 1.1 and 1.2 MeV/u and three seven gap resonators, which allow the variation of the final energy. With an energy of the radioactive beams between 0.8 MeV/u and 2.2 MeV/u a wide range of experiments in the field of nuclear spectroscopy, astrophysics and solid state physics will be addressed by REX-ISOLDE.