Scattering of High-Energy Electrons by Nitrogen-14 and -15

Abstract

Cross sections of elastic and inelastic electron scattering at incident electron energies of 250 and 400 MeV are presented. Data are given for elastic and inelastic scattering from ${\mathrm{N}}^{15}$ and elastic scattering from ${\mathrm{N}}^{14}$. The data are analyzed with the use of the shell model, in Born approximation. The rms radius of ${\mathrm{N}}^{14}$ is found to be 2.64 F at 400 MeV. The rms radius of ${\mathrm{N}}^{15}$ at 250 and 400 MeV is 2.65 and 2.63 F, respectively. Excited levels in ${\mathrm{N}}^{15}$ at 5.3, 6.3, and 7.3 MeV are studied. Values of the nuclear transition probabilities are presented for these levels. The spin and parity assignments made are $J^{\pi }={\frac{5}{2}}^{+}$ and $J^{\pi }={\frac{1}{2}}^{+}$ for the doublet at 5.3 MeV. The 6.3-MeV level is assigned $J^{\pi }={\frac{3}{2}}^{-}$. Of the triplet of levels at 7.3 MeV, only the 7.3- and 7.5-MeV levels are strongly excited. These agree with $J^{\pi }={\frac{3}{2}}^{+}$ and $J^{\pi }={\frac{7}{2}}^{+}$, respectively.