O16(p,α)N13 and O16(p,p)O16* Differential Cross Sections

Abstract
The differential cross sections for the inelastic scattering of protons by O16 and for the O16(p,α)N13 reaction were measured for Ep from 7.18 to 12.90 MeV. A differentially-pumped gas scattering chamber with a solid-state detector was used. Data at θlab=16600 were taken in energy steps ≤ 5 keV and with a target thickness ≤ 3 keV. Seven other excitation curves were taken for 7.18<~Ep<~10.5 MeV at θlab=13348, 116° 34′, 100° 19′, 86° 24′, 61° 36′, 51° 25′, and 33° 47′. These curves were taken with energy steps ≤ 23 keV depending upon the width of the resonance structure. The target thickness was ≤ 3 keV. Data were obtained on the alphas leaving N13 in its ground state and on the inelastic protons leaving O16 in its first, second, third, and fourth excited states. Evidence was found for the existence of 36 levels in F17, the compound nucleus. Below Ep=10.5 MeV, center-of-mass angular distributions were picked from the eight excitation curves and fitted with Legendre polynomials. Levels in F17 at the following excitation energies were assigned total widths, spins, and parities as indicated: Ex=7.73 MeV, Γc.m.=0.178 MeV, Jπ=12+; 8.07, 0.104, 52+; 8.2, 0.706, 32; 8.38, 0.011, 52; 8.42, 0.042, 72+; 8.72, 0.188, 52+; 8.95, 0.122, 52; 9.16, 0.188, 32+; 10.05, 0.282, 72. All parity assignments except those for the levels at