Measurement of 54Fe(n,2n)53Fe reaction cross-sections at 14 MeV neutron energies using activation method and its relevance for fusion-plasma temperature diagnosis

Measurement of the (n, 2n) reaction cross-sections of iodine and cesium induced by D-T neutrons with covariance analysis*

“…A standard 152 Eu point source of known activity was used to calibrate the efficiency of the HPGe detector. Various characteristic γ-rays of 152 Eu were measured by placing the source at a distance of approximately 5 cm from the detector [32,33]. The nine considered characteristic γ-rays of the standard 152 Eu source were 121.782 keV, 244.697 keV, 344.279 keV, 411.117 keV, 778.905 keV, 867.380 keV, 1112.067 keV, 1299.142 keV, and 1408.013 keV.…”

“…2. The efficiency calibration curve was fitted to a polynomial function to obtain the most accurate values using the following expression [23][24][25]33]:…”

“…The covariance matrix at the characteristic γrays of the reaction products 126 I, 132 Cs, and 92m Nb was determined by the equation in Refs. [25,33]. Table 2 presents the detector efficiency estimates corresponding to the characteristic γ-ray energies of the reaction products along with the correlation matrix.…”

“…A considerable improvement in accuracy was achieved for the measured data in this study, which indicates that appropriate covariance analysis can improve data precision. Considering the correlation of uncertainties arising from various sources of experimental error, the final uncertainty results should be evaluated more accurately [33].…”