Neutrons produced by 1.22 GeV antiproton interactions with nuclei
Inclusive neutron energy spectra were measuredb y time of flight using 1.22 GeV antiprotons from LEAR, CERN, as projectiles andtargets from natural Al, Cu, Ag, Ho, Ta, Au, Pb, Bi, U. The sum of two Maxwellian distributions was fitted to the spectra d2σ/(dΩdE) obtainedat several forward andbac kwardangles yielding neutron multiplicities Mi andslop e or temperature parameters Ti for the low-energy (evaporative, i = 1) andhigh-energy (pre-equilibrium, i = 2) parts, respectively. M1 increases with A, proportional to the nuclear volume, and M2 is growing with A1/3, proportional to the nuclear radius. The T parameters are nearly independent of A. The results are comparedwith previous multiplicity measurements with a 4π neutron detector, intranuclear cascade calculations and neutron spectra from stoppedan tiproton annihilation on nuclei. With the measuredproton spectra also the ratio of emitted neutrons to protons was determined for Au.