Proton-Proton Bremsstrahlung at 730 MeV

We have measured the differential cross section for proton-proton bremsstrahlung at sixteen photon angles for 730-MeV incident protons. At all angles, the photon spectra fall smoothly with increasing photon energy up to $E_{\gamma }\sim 80$ MeV and are in quantitative agreement with the prediction of external-emission dominance (EED). Above $E_{\gamma }\sim 80$ MeV the spectra are consistently above the EED calculations.