Excitation and neutron decay of xenon by forward-angle scattering of 250 A MeV 17O ions

Abstract

A technique to study giant resonances by forward-angle scattering of heavy ions in the energy range 100–470 A MeV, using one quadrant of the CELSIUS storage ring as a magnetic spectrometer, is presented. The reaction nat Xe( 17O, 17O′n) has been studied at E( 17O) =250A MeV . A structure in the excitation energy spectrum, compatible with the isovector dipole resonance and the isoscalar quadrupole resonance, was observed, together with a possible candidate for the isovector quadrupole resonance. In addition to neutrons from statistical decay, a large number of non-statistical neutrons in the range E n =5–30 MeV was observed, with a forward-peaked angular distribution.