Positive Pi-Meson Interactions in Beryllium

A 10-in. diameter magnet cloud chamber containing a ¼-in. Be plate has been operated in both the 40-Mev and 50-Mev ${\pi }^{+}$-meson beams of the Rochester 130-in. cyclotron. Meson interactions in Be were obtained for three bands of energy: 15 to 30 Mev, 25 to 40 Mev, and 35 to 50 Mev. The events recorded as nuclear interactions were: stars, stops, and scatterings of greater than 30 degrees. From a survey of some 22 700 g/${\mathrm{cm}}^2$ of Be traversed, a total of 159 such events were found. Analysis of the data from each energy band indicates the absorption cross section to be energy dependent. The ratio of corrected stars to corrected scatterings was found to be roughly 2:1.