VIBRATIONAL CHARACTER OF PD-104 AND A SPECTROSCOPIC STUDY OF PD-104 BY PICKUP REACTIONS

The Pd105(d,t)Pd104 and Ag107(p,α)Pd104 pickup reactions were studied at bombarding energies of 17 and 12 MeV, respectively. Tritons were detected by nuclear emulsions in an Enge split-pole spectrograph with 5-7-keV resolution, and 43 (d,t) angular distributions were measured for transitions to low-lying levels in Pd104. Comparison of the (d,t) data with distorted-wave Born-approximation (DWBA) calculations predominantly led to l=0,2,and4 assignments and yielded spectroscopic factors and quantitative estimates for single-neutron state occupancies. A previously postulated doublet at 1.33 MeV was resolved as a nearly degenerate triplet, in agreement with the two-phonon description for collective vibrations. Further evidence for the vibrational structure of the low-lying levels of Pd104 might be furnished by the well-isolated multiplet near 1.80 MeV, which may contain some or all of the members of the three-phonon quintet. In the (p,α) experiment, cross sections were found to be very small (<20 μb/sr), and thick targets had to be used which limited the resolution to 40 keV for Si detector data and 30 keV for magnetic spectrograph analysis. (p,α) angular distributions are given for the four strongest groups below 2 MeV. Very good agreement between the experimental results and j-dependent DWBA calculations based on a triton-cluster transfer mechanism supports the interpretation that direct pickup is the dominant (p,α) reaction process in this mass and energy region. © 1969 The American Physical Society.