Part I. Study of Some Beta Decays in the SD Shell. Part II. Comparison of Experimental Reaction Cross Sections with the Hauser-Feshbach Model

Part One The beta decays of 19Ne, 23Mg, 27Si, 37K, 38K, and 39Ca have been studied by observing the delayed gamma radiation with large vo1ume Ge(Li) detectors. A pneumatic shuttle was used so that weak beta transitions could be observed. Two previously unobserved allowed transitions have been found, and the uncertainty for most of the previously known transitions has been reduced. Limits for unobserved transitions have been strengthened. A comparison is made between the predictions of various nuclear models, particularly the many-particle shell model; and observed values. Part Two Cross sections have been measured by the activation method for 23Na(p,n)23Mg, 35Cl(α,n) 38K, and 63Cu(p,n)63Zn from threshold to 11 MeV and for 59Co(α,n)62Cu, 63Cu(α,n)66Ga, and 65Cu(α,n)68Ga from threshold to 19 MeV. The excitation functions are compared with the predictions of the Hauser-Feshbach model of nuclear reactions. If resonance effects ar2 averaged, then using established parameters for the nuclear potentials and for the nuclear level densities, the predicted values are within a factor of 2 of the experimental values for practically all cross sections measured. For cases where direct reactions are not important, agreement to within 20% is obtained.