E4 and M5 excitations of 19F nuclei

A form factor of 19F nuclei was measured by exciting 2.78 MeV 9/2+ level, which was considered to belong to the ground rotation of the 19F nuclei by inelastic electron scattering. The excitation of this level is performed by E4 and M5 transitions from the ground state. The form factor measured was apparently contributed by transverse components. The experiment was made by using the electron beam, whose incident energy was 134.5 MeV, 150 MeV and 250 MeV discretely, generated by an electron LINAC of Tohoku University. The mixing among rotation bands as a result of rotation - particle connection was calculated on the basis of the wave function of Nilsson model. From the wave function calculated, the form factor corresponding to each level was calculated and compared with experimental data. The C4 and M5 form factors calculated above showed that they satisfactorily agreed with phenomenalistically analyzed results, and that to 2.78 MeV 9/2+ level, the Coriolis' force played an essential role. The transverse component form factor was very effective to the test of rotation - particle connection model. The observation of the transverse component form factor in low exciting state is difficult in general, however, in case of odd nuclei, high multiple magnetic excitation can be clearly distinguished from Coulomb excitation, so that it is expected that the transverse component form factor may give new information for nuclear structure. (Tai, I.)