Doppler-shift lifetime measurements in ^4^6Ti and ^5^0Cr - Assimakopoulos, P.A.; Becker, T.; Moazed, C.; Van Patter, D.M. (Elsevier)
The lifetimes of nine states in ^4^6Ti and fourteen states in ^5^0Cr have been measured through the Doppler-shift attenuation method. The states were populated by the ^4^6Ti(p, p'γ) and ^5^0Cr(p, p'γ) reactions at E"p = 7 MeV. Thick targets (~ 300 keV) were used to provide adequate averaging over many compound-nucleus levels. Singles γ-ray spectra were obtained with 33 and 55 cm^3 Ge(Li) detectors at θ"γ = 0^o, 90^o and ~ 160^o, and lifetimes were extracted from the observed centroid shifts. An alternative method of analysis, involving a simulation of profiles of Doppler-shifted peaks with six free parameters gave considerably more accurate results. Both methods were tested by measuring known lifetimes in ^5^8Ni. In addition, the lifetimes of three states in ^5^2Cr were determined. A comparison of the energy spectra and electromagnetic decay properties of these nuclei to shell-model calculations revealed the failure of the simple (f"7"2)^6 picture. A startling example of this failure is the fact that the 2"2^+(E2)2"1^+ rate in ^4^6Ti appears to be a factor of 25 faster than that in the cross-conjugate nucleus ^5^0Cr.
http://linkinghub.elsevier.com/retrieve/pii/0375-9474(72)90161-3
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