Study ofAr42Using theAr40(t,pγ)Ar42Reaction

Nuclear properties of the excited states of ${}_{}{}^{42}{}_{}{}^{}\mathrm{Ar}$ were measured by using the ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ar}(t,p\gamma ){}_{}{}^{42}{}_{}{}^{}\mathrm{Ar}$ reaction at a bombarding energy of 2.9 MeV. Angular correlations of $\gamma$ rays were measured using a spectrometer consisting of five NaI(T1) counters in time coincidence with an annular particle detector positioned about 180°. The analysis of these correlations yielded multipole-mixing and branching-ratio information for the electromagnetic deexcitations of ${}_{}{}^{42}{}_{}{}^{}\mathrm{Ar}$ states, as well as spin assignments for some of the excited states. Coincident $\gamma$-ray spectra were also obtained using a Ge(Li) detector. Some of the measured excitations and spin assignments [$E_x$ (kev); $J$] are: [1207±1.5; 2], [2414±5], [2485±3; 2], [2510±3], [3012±3; 1,2,3], [3092 ±3; 4], [3555±3; 2], [4004±5], [4123±4;≤2], [4285±5, 1,2,3], and [4629±5;≥1]. The results of this experiment are compared with recent shell-model calculations.