Decay spectroscopy is one of the oldest indirect methods in nuclear astrophysics. We have developed at TAMU techniques to measure beta- and beta-delayed proton decay of sd-shell, proton-rich nuclei. The short-lived radioactive species are produced in-flight, separated, then slowed down (from about 40 MeV/u) and implanted in the middle of very thin Si detectors. These allowed us to measure protons with energies as low as 200 keV from nuclei with lifetimes of 100 ms or less. At the same time we measure gamma-rays up to 8 MeV with high resolution HPGe detectors. We have studied the decay of Al, P, Cl, all important for understanding explosive H-burning in novae. The technique has shown a remarkable selectivity to beta-delayed charged-particle emission and works even at radioactive beam rates of a few pps. The states populated are resonances for the radiative proton capture reactions Na(p,γ) Mg (crucial for the depletion of Na in novae), Al(p, γ) Si and P(p,γ) S (bottleneck in novae and XRB burning), respectively. More recently we have radically improved the technique using a gas based detector we call AstroBox.
|Name||AIP Conference Proceedings|
|Publisher||AMER INST PHYSICS|
|Conference||4th International Conference on Proton Emitting Nuclei and Related Topics|
|Period||6/06/11 → 10/06/11|
- nuclear astrophysics
- b-delayed proton decay
- resonant proton capture