Experimental determination of the moments of the generalized oscillator strength distribution of He

Abstract

We report here the experimental determination of the moments, S(n,K), of the generalized oscillator strength (GOS) distribution of Helium for n=−5,−4,−3,−2,−1,1,2. Our results for n=1,2 agree with the recent calculation of Sharma and Thakkar. Our results for n=−5, −4, −3, −2, and −1 agree, in the optical limit, to the earlier reported values of the moments of the optical oscillator strength distribution. We also discuss the problems encountered in using the Bethe sum rule for normalizing spectra taken at a fixed angle over a finite energy loss range.