Proton-Proton Bremsstrahlung at 99 MeV

Measurements of the proton-proton bremsstrahlung cross section $\frac{d\sigma }{d{\Omega }_{1}d{\Omega }_2}$ at 99 MeV are reported. Cross sections of 3.77±0.23, 5.14±0.22, 9.01±0.33, and 18.83±1.15 μb/${\mathrm{sr}}^2$ were obtained at angles of 25°, 30°, 35°, and 40°, respectively. The angular distributions of the photons were determined kinematically. The results agree generally but not in detail with theoretical predictions.