The accurate system analysis of the (gamma,xn), (gamma,n) and (gamma,2n) reaction cross section data obtained by using quasimonoenergetical annihilation photon beems at Livermore (USA) and Saclay (France) was carried out for 19 (for 7 - at first) nuclei 51V, 75As, 89Y, 90Zr, 115In, 116,117,118,120,124Sn, 127I, 133Cs, 159Tb, 165Ho, 181Ta, 197Au, 208Pb, 232Th, 238U. It was observed that the (,xn) reaction cross section data obtained at both laboratories without using neutron multiplicity sorting procedure disagree by 10 - 15 %%. Additionally it was found out that the disagreement of partial reactions (gamma,n) and (gamma,2n) cross sections, obtained at both laboratories using neutron multiplicity sorting procedure are significantly more (till 30 - 40 %%) and as a rule have opposite directions. These disagreements were interpreted as the result of difference of neutron multiplicity sorting procedures used in both laboratories: that is incorrect at Saclay with the result of incorrect transmission of the part of (gamma,2n) reaction cross section into the (gamma,n) reaction cross section. The special method was used to move the data into consistence. Its idea is that correspondent 'false' part of (gamma,n) reaction cross section is recalculated and transmitted back into (gamma,2n) reaction cross section. For all 19 nuclei isted the jointly corrected (gamma,xn), (gamma,n) and (gamma,2n) reaction cross sections were evaluated and prepared for including into the EXFOR nuclear reaction database.

Document number: 2003-2/715

Authors: V.V.Varlamov, N.N.Peskov, D.S.Rudenko, M.E.Stepanov

Email: e-mail:

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