MEASUREMENT OF 235U FISSION CROSS SECTION AROUND 14 MeVDepartment of Nuclear Engineering, Tohoku University Aoba, Aramaki, Sendai, Miyagi 980, Japan The neutron-induced fission cross section of U-235 was measured at five neutron energy points from 13.5 to 14.9 MeV by a newly developed detector which coupled a proton-recoil counter telescope with a fission chamber in back to back form. An experimental test of this detector was performed using the time correlated associated particle method. The experimental neutron sensitivity agreed with the analytical one within 1%. The fission cross section measurement was carried out for an U-235 sample with a purity of 99.91%. The overall uncertainties of the measurement were 2.5-2.8%. The present results agreed well in magnitude and in energy dependence, respectively, with the results by Cancé and by Czirr. KEYWORDS: fission cross section, 235U, absolute, counter telescope, T(d,n) reaction |