Very Low Energy Protons From The Beta Decay Of Proton Rich Nuclei For Nuclear Astrophysics

摘要

The MARS group at TAMU has developed a new experimental technique to measure very low energy protons from β-delayed proton-decay of proton-rich nuclei produced and separated with the MARS recoil spectrometer at TAMU. Recently we have investigated the β-delayed p-decays off ~(23)A1 [1], and ~(31)C1 [2], and obtained information on the resonances in the ~(22)Na(p,y)~(23)Mg and ~(30)p(p,y)~(31) S reactions, respectively. These reactions are important in explosive H-burning in Novae [3]. Recently an experiment looking at the β-delayed p-decay of ~(20)Mg was also done in order to obtain information on resonances in the ~(19)Ne(p,y)~(20)Na reaction. A simple setup consisting of a telescope made of a thin double sided Si strip detector (p-detector) backed or sandwiched between two thick Si detectors (β-detectors) was designed. We studied different WI and BB2 p-detectors made by MSL, and found that the thinner detectors with a small cell size are best to measure proton energies as low as 2-300 keV.