Nuclear data sheets for A = 215,219,223,227

Abstract

This publication presents evaluated spectroscopic data and corresponding level schemes from radioactive decay and nuclear reaction studies for all nuclei with mass numbers A=215, 219, 223, and 227. Nuclei with mass number A=215 have spherical shape, and their nuclear structure has been interpreted in terms of the shell model. Nuclei with mass number A=219 belong to a transitional region, with spherical, quadrupole, and possibly, octupole deformations, and those with mass numbers A=223 and 227, to newly studied regions of deformations (pure quadrupole coexisting with possible octupole). Because deformations are small in these regions, nuclear states are no longer fully characterized by single Nilsson orbitals. This terminology, however, is used throughout this evaluation to label states rather than to accurately describe their nature. Highlights of this publication include the emission of 14C by 223Ra, discovered by Rose and Jones (84Ro30), and its fine structure, measured by Brillard et al. (89Br34). This constitutes a new mode of decay and provides additional arguments for configuration assignments. They further include the first set of nuclear levels in 215Fr, 215Ra, and 215Ac, determined from in—beam γ-ray spectroscopic measurements. Two major publications have been extensively used in this evaluation: the theoretical paper “Reflection—asymmetric Rotor Model of Odd—A ≈219–229 Nuclei” by Leander and Chen (88Le13), which presents a calculation of single—particle state properties by the coupling of shell—model states to a reflection—asymmetric rotor core; and the review paper “Intrinsic States of Deformed Odd—A Nuclei in the Mass Regions (151≤A≤193) and (A≥221)” by Jain et al. (90Ja11), which gives the systematics and assignments of single—particle states in such mass regions. These evaluations for A=215, 219, 223, and 227 supersede the earlier ones by C. Maples: 77Ma29, Nuclear Data Sheets 22, 207 (1977); 77Ma30, Nuclear Data Sheets 22, 223 (1977); 77Ma31, Nuclear Data Sheets 22, 243 (1977); and 77Ma32, Nuclear Data Sheets 22, 275 (1977).