Abstract
The spectra of residual nuclides following 100-, 160-, and 220-MeV and bombardment of have been measured by detecting prompt and, at 220 MeV, -delayed gamma rays. A wide spectrum of residual nuclides extending along the valley of stability down to Ca, is seen. Where radioactivities were measured, the total (prompt + delayed) observed cross section amounted to ≈ 900 mb. The mean number of nucleons removed increased from about 5 for the target to about 8 for . The residual nuclide spectrum depends sensitively on the target neutron excess, but is essentially independent of pion charge or pion energy in the range observed. A Monte-Carlo cascade-evaporation calculation involving an intermediate resonance reproduces the yield of residual nuclides far (more than about eight nucleons) removed from the target, but it fails to reproduce the yield of nearer nuclides which is a more sensitive measure of the early stages of the reaction.
NUCLEAR REACTION , MeV; measured prompt and -delayed spectra; determined yields of residual nuclides and their distribution; established systematics. Enriched targets.
- Received 13 July 1978
DOI:https://doi.org/10.1103/PhysRevC.18.2656
©1978 American Physical Society