Nuclear Data Sheets for A=231

Spectroscopic data for all nuclei with mass number A=231 have been evaluated, and the corresponding level schemes from radioactive decay and reaction studies are presented. Highlights of this evaluation include: A new interpretation of gamma-ray spectroscopic results measured with the GAMMASPHERE spectrometer (2002AbZV, 2000JaZY, 1999Br17) has established the level structure of the ground state rotational band 1/2[400] up to spin/parity 45/2+ in Ac-231. Precise measurements of energies and cross sections of scattered tritons from the Th-232(d, t) reaction has produced or confirmed the identification of several rotational bands in Th-231. The alpha hindrance factors (HF) presented in this evaluation were calculated using values of the radius parameter (r(0)) interpolated from those for even-even adjacent nuclei given in 1998Ak04. The Limitation of Relative Statistical Weight (LWM) method (1985ZiZY) has been used for discrepant data throughout this evaluation.