Measurements of U-235 Fission Neutron Spectrum Averaged Cross Sections for Threshold Reactions

Abstract

Integral cross section / Activation technique / Fission spectrum / Threshold reactions / Fast neutrons dosimetry / Neutron spectrum unfolding AbstractMeasurements of fission neutron spectrum averaged cross sections have been performed for several activation reactions, with thresholds in the energy interval from 1.2 to 13.5 MeV, by using high resolution y-ray spectroscopy. The results obtained are presented with a complete uncertainty covariance matrix and are compared with evaluated values and previous measurements.

Measurement of cross sections of threshold detectors with spectrum average technique

“…Comparator UO 2 The purity of all samples was more than 99%. The polyethylene tubes were placed into a Cd cover with the thickness of 0.7 mm.…”

“…In the literature, although there are many studies in which fission neutron spectrum [1][2][3] and 7 Li( p, n) 7 Be, T( p, n) 3 He, D(d, n) 3 He and T(d, n) 4 He are used for the measurement of neutron cross sections for the 103 Rh(n, n ) 103m Rh, 115 In(n, n ) 115m In, 232 Th(n, f ), 47 Ti(n, p) 47 Sc, 64 Zn(n, p) 64 Cu, 58 Ni(n, p) 58 Co, 54 Fe(n, p) 54 Mn, 46 Ti (n, p) 46 Sc, 27 Al(n, p) 27 Mg, 56 Fe(n, p) 56 Mn, 24 Mg(n, p) 24 Na, 59 Co(n, α) 56 Mn, 27 Al(n, α) 24 Na and 48 Ti(n, p) 48 Sc threshold detectors, it is not possible to find a study where (α, n) neutron spectrum is used, except for the study done by Çelenk and Bayar [26].…”

Measurement of the Thermal Neutron Capture Cross Section of Cs-137

“…A precision reference pulser was used at the end of the gamma spectrum, in order to correct for dead time and pile-up losses. More details of the calibration procedure can be found elsewhere [1,2,9]. The decay scheme parameters used in the calibration are shown in Table 1.…”

“…In previous works of this laboratory, the cross sections for several threshold reactions induced by fast neutrons were measured [1,2]. The present work is the start-up of a series of measurements to be carried out in order to obtain the thermal neutron capture cross section induced in radioactive nuclei relevant to nuclear technology.…”

Measurement of the thermal neutron capture cross section and resonance integral of Am-241

“…A precision reference pulser was used, in order to correct for dead time and pile-up losses. More details on the calibration procedure can be found elsewhere [18][19][20]. The decay scheme parameters used in the activity measurements are shown in Table 2 [29] b: Theoretical estimate using α from reference [22].…”