Thin (∼2 kev) gas targets have been used for high-resolution studies of ${\mathrm{N}}^{14}(\alpha , \alpha ){\mathrm{N}}^{14}$ differential cross sections for $1.0<\mathrm{}{E}_{\alpha }<2.4\mathrm{}$ Mev. Data were taken at five angles. Resonances were observed at $E_{\alpha }=1.533, 1.620, 2.165, 2.351, \mathrm{and} 2.370$ Mev. The Wigner-Eisenbud formalism was used to extract resonant parameters (where possible) of the corresponding virtual states of ${\mathrm{F}}^{18}$. Also ${\mathrm{O}}^{16}$(${\mathrm{He}}^3$,${\mathrm{He}}^3$)${\mathrm{O}}^{16}$ and ${\mathrm{O}}^{16}$(${\mathrm{He}}^3$,${\mathrm{He}}^4$)${\mathrm{O}}^{15}$ differential cross sections were measured for $1<\mathrm{}{E}_{{\mathrm{He}}^3}<3\mathrm{}$ Mev. A 300-kev broad resonance at $E_{{\mathrm{He}}^3}=2.360\mathrm{}$ Mev was shown to result from a ${\mathrm{½}}^{+}$ state of ${\mathrm{Ne}}^{19}$. The elastic width is 0.11 of the total width.

• Received 22 June 1961

DOI:https://doi.org/10.1103/PhysRev.124.868