Gamma-Ray Angular Distribution, Angular Correlation, Linear Polarization, and Doppler-Shift Attenuation Measurements in the ⁴⁶Ti(α, nγ) ⁴⁹Cr Reaction

Abstract

A detailed investigation of the electromagnetic properties of the ⁴⁹Cr levels below 3 MeV has been made. The levels were populated by the ⁴⁶Ti (α, nγ) ⁴⁹Cr reaction at E_α=8 MeV. Analysis of measured gamma-ray angular distributions, linear polarizations, and gamma-gamma angular correlations has given the following unique spin and parity assignments: 9⁄2⁻ to the 1083-keV level; 1⁄2⁻ to the 1703-keV level; 5⁄2⁺ to the 2432-keV level; and 7⁄2⁻ to the 2503-keV level. In addition, a unique 5/2 assignment has been given to the 2168-keV level. Lifetimes of some levels have been obtained from Doppler-shift attenuation measurements. New or revised values of branching ratios and mixing ratios have been determined for many transitions. The unique 5⁄2⁺ assignment to the 2432-keV level and a large B (E2) value obtained for the transition to the 1981-keV 3⁄2⁺ level suggest that the 2432-keV level is a member of the K^π=3⁄2⁺ band built on the 1981-keV level.