The relative yield of neutral photopions from various elements was determined as a function of the quantum limit energy of the Berkeley synchrotron. Single decay photons from neutral pions were observed at 45, 90, and 135 deg to the incident bremsstrahlung in the laboratory system. Mean free paths for neutral pions in nuclear matter were obtained, an optical model prediction of the photopion yields based upon pion-nucleus scattering data was confirmed, and the presence of coherent pion production in the forward direction was detected.

Abstract. A systematic procedure for preparing purchase specification on electronic instrumentation or control systems has been developed. This procedure results in preparation of specifications which: 1) make it possible to find any particular specification requirement quickly; and 2) insure that no important requirement has been omitted. Details of this systematic specification preparing procedure presented.