Multiple scattering measurements in nuclear emulsions

Abstract

The practical use of the new multiple scattering function, cos ηφ, introduced byLipkin (1)et al., was examined by comparing its theory with experiment. At the same time the mean absolute angle according to Moliere’s scattering theory was compared with experiment for the second and third difference and the respective dispersions were determined experimentally. (The theoretical dispersion diverges in Moliere’s theory.) A good agreement between theory and experiment was obtained in the cosine case, both for the mean value and the dispersions, as well as in the mean absolute angle case with cut-off. Writing the relative error ofpβ as\(D_{2.3} /\sqrt n \) (for the second and third differences, respectively) we have obtained in the cosine case: D2 = 0.976 and D3=1.36, and in the mean absolute angle case (with cut-off at ( ):D2 = 0.97 andD3 = 0.137. It is shown that, provided one restricts oneself to a certain class of estimates ofpβ, the above dispersion values are close to the minimum possible dispersion ofpβ. Also, an explanation is suggested for the known experimental fact that the ratio of the « scattering constants »K3/E2is higher by a few percent than the expected value √3/2.