Measurement of neutron inelastic scattering cross-section for the first level of U-238 in hundreds of keV range

Neutron inelastic scattering cross-section for the first level of U-238 (Ex = 44.9 keV) was measured for eight incident energy points from 350 to 855 keV at laboratory angle of 120 degrees by using a time-of-flight spectromet er. Care was taken for the peak separation of the first level from the grou nd state, and for the absolute normalization of the cross-section. The peak separation was achieved by employing a thin neutron production target (Del ta E less than or equal to 10 keV), a long flight path (4-6 m), and by expe rimental simulation of the elastic scattering peak with a lead sample. Vali dity of the absolute value and internal consistency in the experiment were confirmed by measuring carbon with well-known cross-sections and U-238 at a nother emission angle, 135 degrees. The angle-integration was performed by employing the angular distribution of JENDL-3.2. The present experimental d ata for the first level and the ground state are close to the JENDL-3.2 dat a. (C) 2000 Elsevier Science Ltd. All rights reserved.