Electrons at five energies between 60 and 120 MeV were used to study the giant electric-dipole and -quadrupole resonances in ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$. Prominent electric-dipole peaks were found at 17.7, 19.1, 20.2, and 23 MeV in good agreement with photoreaction results. In addition our analysis reveals weaker fragmented electric-dipole strength in the region between 12.5 and 15 MeV. Prominent electric-quadrupole peaks were found at 13.0, 13.7, and 16.2 MeV, and a broad peak was found from 14.2 to 15.9 MeV. Two different analyses reveal a broad quadrupole excitation between 16 and 25 MeV. The dipole and quadrupole resonances deplete about 65% and 100% of the energy-weighted sum rule, respectively.

[NUCLEAR REACTIONS ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}(e,e^{\prime })$, $E=59.5, 84,7, 89.8, 109.6, 119.7$ MeV, $q=0.35\mathrm{}$ ∼ 0.9 ${\mathrm{fm}}^{-1\mathrm{}}$, enriched gas target, measured $\sigma \left(E^{\prime }\theta \right)$ up to 25 MeV in excitation energy; deduced dipole and quadrupole strengths in giant resonance region.]

• Received 29 August 1977

DOI:https://doi.org/10.1103/PhysRevC.17.435