Low-energy pion production with 800 MeV/N Ne20

Doubly differential cross sections for production of positive pions (20MeVTLab100 MeV) in bombardment of Ne20 on NaF, Cu and Pb targets at 800 MeV/N have been measured with a range telescope. The results showed that the angular distribution of low-energy pions in the nucleon-nucleon center of mass (Tc.m.50 MeV) was isotropic, even 90° peaking at 15 MeV c.m. The intermediate-energy pions (50Tc.m.300 MeV) were forward and backward peaked, reflecting the individual nucleon-nucleon process in the isobar model of production. The observed cross sections were shown to be generally reproduced by an incoherent superposition of the experimental (p + nucleus) cross sections. NUCLEAR REACTIONS NaF, Cu, Pb(Ne20, +)X, EA=800 MeV/nucleon; measured (E), E=20-100 MeV, =30-150°.