Photospallation of complex nuclei at intermediate energies. Pt. 2

Photospallation yields from 197Au, 139La, 133Cs, 127I, 89Y, 59Co and 51V were analyzed using iterative non-linear least-squares fits to Rudstam's five-parameter (P, σ, R, S and T) CDMD formula which was modified to include the corrections of isobaric precursor decays. The expressions for the parameters P and σ obtained in the present analysis were found to be applicable to 51 ≤ At ≤ 133 and different at E0 ≥ 600 MeV, 300 ≤ E0 ≤ 600 MeV, and possibly 100 ≤ E0 ≤ 300 MeV. For the heavier targets (At ≥ 140), the P values appear to be smaller and the σ larger than the predictions of the proposed expressions. The parameter R was confirmed to be expressed as R = d' A-e', and the new values of d' and e' have been proposed. The values of S and T are essentially the same as those previously reported by Jonsson and Lindgreen. The yields of the products near the targets of 51 ≤ At ≤ 197, from (γ, χn) reactions at Eo ≥ 300 MeV or possibly E0 ≥ threshold, were found to be expressed as a function of At and χ. Implications of the newly derived expressions are discussed in the light of reaction mechanism, comparing with those of hadron reactions. (orig.)