Beta-decay of proton-rich $^{31}$Cl and its relevance for explosive H-burning

We produced and separated proton-rich nucleus $^{31}$Cl with the MARS recoil separator at TAMU. Then studied its beta-gamma and beta-delayed proton-decay using techniques designed for low-intensity, short-lived sources. The states populated in the daughter nucleus $^{31}$S above the proton threshold at S$_{p}$=6133 keV are resonances in the proton capture reaction $^{30}$P(p,$\gamma )^{31}$S, crucially important for the explosive H-burning novae. The setup consisted of a telescope made of a thin double sided Si strip detector (p-detector) BB2-45 and a thick Si detector ($\beta $-detector). A HpGe detector outside the chamber detected $\gamma $-rays. The source nuclei produced at about 32 MeV/u were slowed down and implanted in the middle of the thin Si strip detector. The technique allowed us to measure very low proton energies (down to 2-300 keV), has shown a remarkable selectivity to $\beta $-delayed charged particle emission, and would work even at radioactive beam rates of a few pps. Furthermore, the half-life of $^{31}$Cl was measured with under 1{\%} accuracy, its Isobar Analog State was located and from IMME its mass excess better determined.