applications on neutron capture gamma-ray spectroscopy

samples irradiated at the core of a nuclear reactor are activated with thermal and epithermal neutrons. the spectrum of the thermal neutrons has approximately a Maxwellian distribution of the neutron velocity. its peak position varies according to the temperature at the irradiation position, the epithermal neutron spectrum is approximately described by 1/E law . generally, in reactors this usually deviates from the ideal 1/E-shape. if these deviations are not considered, errors will occur in the results of the activation analysis. in these cases, the epithermal neutron spectrum is better described by 1/E1+a , the epithermal neutron spectrum deviation α is different in different reactors and depends also on the irradiation positions