F19(p, t)F17andF19(p, α)O16Reactions at 22.8 MeV

Abstract

The differential cross sections for the ${\mathrm{F}}^{19}(p, t){\mathrm{F}}^{17}$ reactions leading to the ground state and first excited state of $F^{17}$, and for the ground-state $\alpha$-particle group and the composite $\alpha$-particle groups corresponding to the two unresolved doublets at 6 MeV (6.05 and 6.13) and at 7 MeV (6.92 and 7.12) of excitation in ${\mathrm{O}}^{16}$ from the ${\mathrm{F}}^{19}(p, \alpha ){\mathrm{O}}^{16}$ reaction, were measured as functions of angle at an incident energy of 22.8 MeV. Data were also obtained for higher excited-state groups from both reactions at several forward angles. The angular distributions for all groups exhibit typical oscillatory variations with angles, to the largest angles observed, 170°. The amplitude of the variations is most pronounced for the ${\alpha }_0$ group. The total cross sections, obtained by numerical integration of the differential cross sections, are 1.84, 1.45, 0.53, 0.43, and 0.45 mb for the $t_0$, $t_{0.5}$, ${\alpha }_0$, ${\alpha }_6$ and ${\alpha }_7$ groups, respectively. The angular distributions of the $t_0$, $t_{0.5}$, and ${\alpha }_0$ groups have been fitted with distorted-wave Born approximation calculations. Exchange interactions do not appear to be required in order to fit these data, although the possibility of knockout processes cannot be eliminated on the basis of the present calculations.