Production of Stopped Pions and Muons from a Multi-Bev Proton Synchrotron

The use of a multi-BeV synchrotron as a high intensity source of stopped pions and muons is discussed. To produce stopped pions extraction of pions at a relatively low energy between 100 and 200 MeV is necessary due to pion absorption in the attenuator used to stop the pions. Although no experimental data appear to be available on the cross section for production of such low energy pions by multi-BeV protons, we can use experimental data on the production of higher energy pions together with an empirical formula for the pion energy spectrum to estimate that the production cross section for 200 MeV positive or negative pions by 30 BeV protons is about 50 μb/sr/MeV/Be9 nucleus at a laboratory angle of 5°. Using such a cross section and considering other relevant factors we conclude that the proton linac accelerator meson factory operating at 500 MeV with 6×1015 protons/sec will produce about 100 times as many stopped pions or muons as could be obtained in practice from the Brookhaven National Laboratory Alternating Gradient Synchrotron operating with an increased intensity of 2×1013 protons/sec.