Investigation of the energy levels of F 21 using the F 19(t, p)F 21 reaction

Abstract

Using the F 19(t, p)F 21 reaction, the energy levels of F 21 up to an exitation energy of 5.9 MeV were investigated. Previously unreported levels were found at 5.35, 5.49, (5.57), 5.59, 5.79 and 5.88 MeV. The energy levels below 5.07 MeV are found to be in agreement with previous work. The proton groups with angular distribution characteristic of direct interactions were interpreted as stripping of two neutrons. This gave 1 2 + for the spin and parity of the 0.28 MeV first excited state. The spins and parities of the ground state and of the 3.45, 3.51, 4.57, 5.07 and 5.59 MeV excited states are 5 2 + or 3 2 + whereas the spin and parity of the 3.63 MeV excited state is tentatively 7 2 − or 5 2 − . A semiqualitative interpretation of the positive parity states in terms of the unified model is attempted.