Gerrit J. Smith

The collective excitation of 103Pd following (heavy ion, xn) reactions

Abstract The energy level structure of 103 Pd was studied using the reactions 100 Ru(α, nγ) 103 Pd and 94 Zr( 12 C, 3nγ) 103 Pd. The experiments included the measurement of γ-ray yield as a function of incident projectile energy, γ-γ coincidence measurements, γ-ray angular distributions, and γ-ray linear polarization measurements. Two ΔI = 2 bands built on the 7 2 + and 11 1 − intrinsic states were observed. The ( 12 C, 3n) reaction was found to be much more effective than the (α, n) reaction in exciting these bands. A decay scheme is presented showing energies up to 6049 keV and spins up to 35 2 . Additional information relating to the coupling between the odd particle and the core is presented. A cascade of six γ-rays in 103 Rh was observed following the reaction 94 Zr( 12 C, p2nγ) 103 Rh.

Collective and two-quasiparticle excitations inPd102,104,106following (C13,3nγ) reactions

Even-A Pd nuclei were studied using the reactions /sup 92/,/sup 94/,/sup 96/Zr(/sup 13/C,3n..gamma..)/sup 102/,/sup 104/,/sup 106/Pd. The experiments included ..gamma..-ray yield as a function of energy, ..gamma..-ray angular distributions, ..gamma..-ray linear polarizations, and ..gamma..-..gamma.. coincidence measurements. A new treatment of ..gamma..-..gamma.. directional correlation from oriented nuclei, which combines data from all appropriate coincidence pairs to reduce uncertainties, has aided in determining multipolarities for 49 contaminated transitions. Extensive decay schemes are presented which include many high-angular-momentum, positive- and negative-parity states. In addition to the ground-state band, there appear to be three collective bands built on excited two-quasiparticle states. The measurements favor a slightly deformed rotor description of these nuclei over an interpretation in terms of a vibrational (interacting boson) model. (AIP)

High-spin states in /sup 42/Ca. [J,. pi. ]

Levels in /sup 42/Ca excited by the /sup 28/Si(/sup 16/O, 2p) reaction have been investigated with E16O = 36--42 MeV. ..gamma..-ray angular distributions and ..gamma gamma.. angular correlations relative to the beam direction have been determined. Level energies, decay modes, spins, parities, and ..gamma..-ray radiative admixtures were extracted. Level energies in keV and preferred J/sup pi/s are: 4099.9 (5/sup -/), 5491.4 (5/sup +/), 5744.1 (5/sup -/), 6144.5 (6/sup +/), 6408.8 (7/sup +/), 6553.9 (7/sup -/), 7368.7 (6/sup -/ or 8/sup -/), and 8297.9 (J/sub 7369/ +- 1). These spin-parity assignments differ from those reported recently by Warburton, Kolata, and Olness. (AIP)

Collective and two-quasiparticle excitations in /sup 102/,/sup 104/,/sup 106/Pd following (/sup 13/C,3n. gamma. ) reactions

Even-A Pd nuclei were studied using the reactions /sup 92/,/sup 94/,/sup 96/Zr(/sup 13/C,3n..gamma..)/sup 102/,/sup 104/,/sup 106/Pd. The experiments included ..gamma..-ray yield as a function of energy, ..gamma..-ray angular distributions, ..gamma..-ray linear polarizations, and ..gamma..-..gamma.. coincidence measurements. A new treatment of ..gamma..-..gamma.. directional correlation from oriented nuclei, which combines data from all appropriate coincidence pairs to reduce uncertainties, has aided in determining multipolarities for 49 contaminated transitions. Extensive decay schemes are presented which include many high-angular-momentum, positive- and negative-parity states. In addition to the ground-state band, there appear to be three collective bands built on excited two-quasiparticle states. The measurements favor a slightly deformed rotor description of these nuclei over an interpretation in terms of a vibrational (interacting boson) model. (AIP)

Collective and two-quasiparticle excitations in Pd-102, Pd-104, Pd-106 following (C-13, C-3n gamma) reactions

Even-A Pd nuclei were studied using the reactions /sup 92/,/sup 94/,/sup 96/Zr(/sup 13/C,3n..gamma..)/sup 102/,/sup 104/,/sup 106/Pd. The experiments included ..gamma..-ray yield as a function of energy, ..gamma..-ray angular distributions, ..gamma..-ray linear polarizations, and ..gamma..-..gamma.. coincidence measurements. A new treatment of ..gamma..-..gamma.. directional correlation from oriented nuclei, which combines data from all appropriate coincidence pairs to reduce uncertainties, has aided in determining multipolarities for 49 contaminated transitions. Extensive decay schemes are presented which include many high-angular-momentum, positive- and negative-parity states. In addition to the ground-state band, there appear to be three collective bands built on excited two-quasiparticle states. The measurements favor a slightly deformed rotor description of these nuclei over an interpretation in terms of a vibrational (interacting boson) model. (AIP)