Antiproton-Proton Cross Sections at 133, 197, 265, and 333 Mev

In a scintillation-counter experiment the interaction of antiprotons with protons in the energy region 133 to 333 Mev has been studied. Antiprotons, produced internally in the Bevatron, channeled externally by a system of magnetic quadrupoles and bending magnets, and identified by time of flight, entered a target containing liquid hydrogen. This target was completely surrounded by a system of scintillation counters which detected both scattered antiprotons and annihilation secondaries. An electrostatic-magnetic velocity spectrometer was used in the external magnetic channel to increase the ratio of antiprotons to pions. The $\overline{p}-p$ total, elastic, inelastic, and charge-exchange cross sections, and the angular distribution of elastic scattering were measured at each energy. The inelastic cross section is approximately one-half the total cross section at these energies. The results are discussed in connection with current theories.