High Energy Photoproton Production by 322-Mev Bremsstrahlung

Abstract

The ejection of high energy protons from various materials by 322-Mev bremsstrahlung has been investigated using a detector telescope consisting of three liquid scintillators. Protons, above a minimum energy of 65 Mev, were distinguished from other particles by their $\frac{\mathrm{dE}}{\mathrm{dx}}$ at a fixed range. At 70 Mev the angular distribution appears to be independent of nuclear complexity; the relative distributions from Li, C, and Ta have about the same shape. Distributions from C at 77, 127, and 174 Mev were measured between 11° and 45°. The data do not fit the predictions of a quasi-deuteron model, but adequate calculations require more knowledge of the deuteron photodissociation process. The yield at 45° for 72- and 142-Mev protons from various materials was found to be directly proportional to $Z$. The energy spectra of photoprotons from C have been measured at 45° and 90°. The absolute differential cross section for production of 72-Mev protons from C at 90° has been measured.