B.C. Robertson

Electromagnetic properties of 51Cr excited states

Abstract The lifetimes of several levels in 51Cr in the excitation range 1165–2767 keV were measured via the 51V(p, nγ)51Cr reaction using the Doppler-shift attenuation method. A value of J π = 9 2 − is assigned to the level at 2766.4 keV, from angular distribution measurement of itsγ-decay mode and from the lifetime determination.

Hole states in 55Fe

Abstract A number of low-lying levels in 55 Fe have been described as hole states. The lifetime of the first two hole states has been measured using the direct-timing and Doppler-shift techniques, and the decay scheme of these and neighbouring levels measured. An unsuccessful search was also made for possible decays from a level which has been reported at an excitation of 2818 keV. The experimental information is compared with various calculations.

Electromagnetic properties of 45Ti excited states

Abstract The lifetimes of several levels in 45Ti were measured via the reaction 45Sc(p, nγ)45Ti using the Doppler-shift attenuation method. The presence of levels at 1.958, 2.260 and 2.432 MeV excitation observed by a neutron time-of-flight technique are reported. Spins of 9 2 − and 11 2 − are assigned to the levels at 1.354 and 1.468 MeV, respectively, from angular distribution measurements of their γ-decay modes and from the lifetime determinations.

The energy level structure of 154Sm from the (n, n′γ) reaction

Abstract Gamma rays from levels in 154 Sm between 921 and 1817 keV excitation were observed following neutron inelastic scattering at neutron energies ranging from 1.1 to 2.3 MeV. Level positions and decay mode information were obtained. Gamma-ray production cross sections were determined and then used to deduce neutron inelastic cross sections. The results were compared with the predictions of the compound nuclear statistical theory to establish level spins and parities.

A study of γ-rays of 37Ar

Abstract The mean lifetime of levels in 37Ar below 3.30 MeV excitation were measured via the 37Cl(p, nγ)37Ar reaction with the Doppler-shift attenuation method. Gamma-ray angular distributions were obtained at various incident energies and compared with the predictions of the statistical compound nuclear model. The angular distribution and lifetime results yield an assignment of J π = 5 2 (+) for the 3.171 MeV level and J π = 9 2 − for the 3.185 MeV level. The experimental results are discussed and compared with shell-model calculations.

Properties of excited states in 48Sc

Abstract The properties of excited states in 48 Sc were studied using the 48 Ca(p, nγ) 48 Sc reaction. The decay scheme of 48 Sc up to 3.16 MeV was determined from γ-ray excitation functions for incident proton energies between 2.6 and 3.9 MeV. Level spins and mixing ratios were assigned by comparing the measured γ-ray angular distributions with the predictions of the statistical compound-nuclear model.

Electromagnetic properties of 55Fe

Abstract Measurements of level positions, lifetimes, decay modes and the deduction of spins in 55 Fe have been carried out using the 55 Mn(p, nγ) 55 Fe reaction. Lifetimes of 12 levels between 1.3 and 3.1 MeV excitation are reported. Spin and mixing ratio assignments are made for levels above 2.2 MeV excitation using a statistical compound nuclear calculation. The measured lifetimes are compared with recent shell-model and intermediate-coupling predictions.