Eur. Phys. J. A (2000) 8: 197-204
https://doi.org/10.1007/s100500070106

Neutrons produced by 1.22 GeV antiproton interactions with nuclei

¹ Physik-Department, Technische Universität München, D-85748, Garching, Germany
² Hahn-Meitner-Institut Berlin, D-14109, Berlin, Germany
³ GANIL, IN2P3/CNRS-DSM/CEA, F-14076, Caen, France
⁴ Institute for Nuclear Research, Russian Academy of Sciences, 117312, Moscow, Russia
⁵ University of British Columbia, Vancouver, B.C., Canada V6T 1Z1,
⁶ Institute of Experimental Physics, Warsaw University, PL-00-681, Warszawa, Poland
⁷ Forschungszentrum Rossendorf, D-01314, Dresden, Germany
⁸ Heavy Ion Laboratory, Warsaw University, Pl-02-097, Warszawa, Poland
⁹ University of Rochester, NY, 14627, USA

Received: 25 February 2000
Revised: 15 May 2000
Published online: 15 June 2000

Abstract

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 d² σ/(dΩdE) obtainedat several forward andbac kwardangles yielding neutron multiplicities M _i andslop e or temperature parameters T _i for the low-energy (evaporative, i = 1) andhigh-energy (pre-equilibrium, i = 2) parts, respectively. M ₁ increases with A, proportional 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 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.