1 research outputs found
Search for Na in novae supported by a novel method for measuring femtosecond nuclear lifetimes
Classical novae are thermonuclear explosions in stellar binary systems, and important sources of Al and Na. While γ rays from the decay of the former radioisotope have been observed through-out the Galaxy, Na remains untraceable. The half-life of Na (2.6 yr) would allow the observation of its 1.275 MeV γ-ray line from a cosmic source. However, the prediction of such an observation requires good knowledge of the nuclear reactions involved in the production and destruction of this nucleus. The Na(p, γ)Mg reaction remains the only source of large uncertainty about the amount of Na ejected. Its rate is dominated by a single reso- nance on the short-lived state at 7785.0(7) keV in Mg. In the present work, a combined analysis of particle-particle correlations and velocity-difference profiles is proposed to measure femtosecond nuclear lifetimes. The application of this novel method to the study of the Mg states, combining magnetic and highly-segmented tracking γ -ray spectrometers, places strong limits on the amount of Na produced in novae, explains its non-observation to date in γ rays (flux < 2.5×10 ph.cm s), and constrains its detectability with future space-borne observatories