Study of the giant resonance by the 40Ca(e,e'n)39Ca reaction

A cross section and angular distribution of 40Ca(e, e' n)39Ca were determined in the isovector giant quadrupole resonance (IVGQR) field. The missing energy spectra showed a peak at 5 MeV higher than the threshold value of neutron emission. It indicated that the decay rate from the excitation energy field higher than GDR to the continuous excitation states at 5 MeV higher than the grand state of the residual nucleus 39Ca was larger than that from the former to the grand state. However, the excitation states could not determined. The angular distribution was asymmetric because there was a large peak in q-direction and a small peak in anti q-direction. It proved the existence of E2. The cross section of (e, e' n) and (γ,n) were compared. The cross section of (e, e' n) continued to the results of (γ,n) until 28 eV of excitation energy, but larger than that in 28 to 35 MeV. (S.Y.)