Extension of the Tz = -3/2, A = 4n + 1 series of beta-delayed proton emitters to 65Se and 73Sr, and low energy beta-delayed proton emission from the Tz = -3/2, A = 4n + 3 nucleus 23Al

The series of known Tz = -3/2, A = 4n + 1 nuclei has been extended to include the previously undiscovered isotopes 65Se and 73Sr, through the observation of beta-delayed proton emission via the isobaric analog state (IAS) of the beta-daughter (emitter). Due to the relatively large proton energies involved, these experiments were conducted using standard Si-Si ΔE-E telescopes. Beta-delayed protons arising from 65Se have been observed at an energy (laboratory) of 3.55 ± 0.03 MeV, corresponding to the decay of the T = 3/2 isobaric analog state in 65As to the ground state of 64Ge. Similarly, beta-delayed protons from 73Sr at an energy of 3.75 ± 0.04 MeV have been observed, corresponding to decay of the T = 3/2 isobaric analog state in 73Rb to the ground state of 72Kr. From the energies of these proton transitions, an improved prediction of the mass excesses of the two parent nuclei (65Se and 73Sr) is made through the use of a Coulomb displacement formula. These predictions are -33.41 ± 0.26 and -31.87 ± 0.24 MeV for 65Se and 73Sr, respectively. Studies of low energy (down to ∼200 keV) beta-delayed protons from 23Al necessitated that a particle identification telescope with a low energy threshold for observation and identification of protons be developed. 23Al is of interest because of its role in the breakout of the hot CNO cycle leading to the astrophysical rp process