Nuclear data sheets for A = 191

Abstract

Level schemes, spin and parity assignments, and decay properties are presented for all nuclei with mass number A = 191. Experimental data and adopted values are given along with conclusions as to the spin and parity assignments. The presentation of the nuclear properties is given in the light of the data and current theoretical ideas. In this transition region, level decay rates are seen to be of particular importance and so have been summarized in terms of multipole enhancement or hindrance. The compilers have attempted to bring out some inconsistencies in the data and resolve discrepancies when possible. Deficiencies in the data include (a) reaction data leading to 191Pt, (b) rigorous spin assignments for 191Pt, and (c) determination of the ground-state properties of 191Hg. An abundance of data on stable 191Ir shows that nuclear deformations are already a prominent characteristic in this transitional nucleus.