Neutron production in coincidence with fragments from the [Formula Presented] reaction at [Formula Presented] and [Formula Presented] MeV

C. Tuv̀e, Università degli Studi di Catania
S. Albergo, Università degli Studi di Catania
D. Boemi, Università degli Studi di Catania
Z. Caccia, Università degli Studi di Catania
C. X. Chen, Louisiana State University
S. Costa, Università degli Studi di Catania
H. J. Crawford, Space Sciences Laboratory at UC Berkeley
M. Cronqvist, Lawrence Berkeley National Laboratory
J. Engelage, Space Sciences Laboratory at UC Berkeley
L. Greiner, Space Sciences Laboratory at UC Berkeley
T. G. Guzik, Louisiana State University
C. N. Knott, University of Minnesota Twin Cities
A. Insolia, Università degli Studi di Catania
P. J. Lindstrom, Lawrence Berkeley National Laboratory
J. W. Mitchell, NASA Goddard Space Flight Center
R. Potenza, Università degli Studi di Catania
G. V. Russo, Università degli Studi di Catania
A. Soutoul, Département d‘Astrophysique
O. Testard, Département d‘Astrophysique
A. Tricomi, Università degli Studi di Catania
C. E. Tull, Louisiana State University
C. J. Waddington, University of Minnesota Twin Cities
W. R. Webber, The University of New Mexico
J. P. Wefel, Louisiana State University

Abstract

Neutron production, in coincidence with fragments emitted in the [Formula Presented] reaction at [Formula Presented] and [Formula Presented] has been measured using a 3-module version of the multifunctional neutron spectrometer MUFFINS. The mean neutron multiplicities for neutrons detected in the angular range covered by MUFFINS [Formula Presented] have been estimated from the comparison between the neutron cross sections, in coincidence with the fragments, and the elemental cross sections. We have found evidence for a preequilibrium emission of prompt neutrons in superposition to a “slower” deexcitation of the equilibrated remnant by emission of nucleons and fragments, as already seen in inclusive rapidity distributions. The energy dependence of the inclusive neutron production cross sections, measured in a previous work, is here interpreted as due to the stronger neutron focusing in the forward direction at the higher energy. Comparison with a BNV+phase space coalescence model is discussed. © 1999 The American Physical Society.