Lifetime and angular-correlation measurements in 47Ti

Abstract

Mean lifetimes of levels below 2.42 MeV in 47Ti were determined with the 47Ti(p, p′γ) 47Ti reaction using the Doppler-shift attenuation method. The results are: 1253 keV, 210±20 fs; 1445 keV, 1.5 −0.3 +0.5 ps; 1550 keV, 2.25 −0.50 +0.50 ps;1795 keV, > 2 ps; 1825 keV, > 2 ps; 2164 keV, 31±8 fs; 2168 keV, 25±6 fs; 2260 keV, 1.2 −0.3 +0.5 ps; 2297 keV, 11±7 fs; 2365 keV, > 1.5 ps; 2408 keV, 31 −10 +13 fs; 2416 keV; > 2 ps. The 48Ti(τ, αγ) 47Ti reaction was used to measure α-γ angular correlations. Decay modes, branching ratios and multipole mixing ratios were determined. Unambiguous spin assignments were obtained for the 1253 keV level ( 9 2 − ) and the 1445 keV level ( 11 2 − )and the number of possible spin values was restricted for some of the higher levels. The energies and spins of the four lowest levels as well as the B( M1) and B( E2) values of their γ-decay are generally in good agreement with calculations based on the rotational model and suggest that these levels are strongly collective.