Neutrons produced by 1.22 GeV antiproton interactions with nuclei

Inclusive neutron energy spectra were measured by time of flight using 1.22 GeV antiprotons from LEAR, CERN, as projectiles and targets from natural A l, Cu, Ag, Ho, Ta, Bu, Pb, Pi, U. The sum of two Maxwellian distributions w as fitted to the spectra d(2)sigma/(d Omega dE) obtained at several forward and backward angles yielding neutron multiplicities Mi and slope or temper ature parameters T-i for the low-energy (evaporative, i = 1) and high-energ y (pre-equilibrium, i = 2) parts, respectively. Mr increases with A, propor tional to the nuclear volume, and M-2 is growing with A(1/3), proportional to the nuclear radius. The T parameters are nearly independent of A. The re sults are compared with previous multiplicity measurements with a 4 pi neut ron detector, intranuclear cascade calculations and neutron spectra from st opped antiproton annihilation on nuclei. With the measured proton spectra a lso the ratio of emitted neutrons to protons was determined for Au.