The recent data of Meyer-Berkhout on the elastic scattering of 420-Mev electrons by ${\mathrm{N}}^{14}$ have been analyzed in the first Born approximation. A detailed treatment is given of the effect of the quadrupole charge distribution of the nucleus in causing a filling-up of the diffraction minimum. The intermediate coupling ground-state wave function of Visscher and Ferrell with an admixture of the spheroidal type of collective wave function, suggested by Fallieros and Ferrell, has been used in calculating the quadrupole form factor. Instead of using the Born approximation monopole form factor, the exact monopole scattering curve computed by Ravenhall from phase-shift analysis has been made use of. The spin-flip type magnetic scattering has also been calculated and found to be extremely small. The experimental data show the importance of the quadrupole charge scattering in the neighborhood of the diffraction minimum of the monopole scattering. The quadrupole scattering for the intermediate coupling is, however, completely inadequate to explain the observed data. This gives strong evidence for a collective enhancement of the ${\mathrm{N}}^{14}$ quadrupole moment through core deformation. The model of Fallieros and Ferrell, which predicts a total quadrupole moment of 3.07×${10}^{-26\mathrm{}}$ ${\mathrm{cm}}^2$ (collective enhancement=2.01×${10}^{-26\mathrm{}}$ ${\mathrm{cm}}^2$), is found to give a fairly good fit with the data.

• Received 14 August 1959

DOI:https://doi.org/10.1103/PhysRev.117.566