The thick-target yield of the reaction ${\mathrm{O}}^{16}(p, \gamma ){\mathrm{F}}^{17}$ has been measured by bombarding ${\mathrm{Al}}_2$${\mathrm{O}}_3$ targets with protons from 140 to 170 kev using currents from 3 ma to 10 ma and counting the induced positron activity of the ${\mathrm{F}}^{17}$. The thick-target yield ranges from (1.9±1)×${10}^{-17\mathrm{}}$ beta/incident proton at 140 kev to (1.47±0.15)×${10}^{-16\mathrm{}}$ beta/incident proton at 170 kev. The corresponding cross sections are (4.6±2.4)×${10}^{-11\mathrm{}}$ barn at 140 kev and (2.34±0.3)×${10}^{-10\mathrm{}}$ barn at 170 kev. The activity was identified by observing the half-life. The cross-section factor $S_0$ was found to be 6.8±1.4 kev-barns between 140 kev and 170 kev bombarding energy.

• Received 26 May 1958

DOI:https://doi.org/10.1103/PhysRev.111.1604