Neutron Activation Cross Sections with Sb—Be Neutrons

Abstract

The neutron activation cross sections near 25 kev have been measured for about 50 nuclei. Gamma-ray scintillation spectrometers with known efficiency were used to compare the radioactivities produced by the several nuclei with ${\mathrm{I}}^{128}$. This gave a significant increase in sensitivity and precision over direct beta-counting methods in many cases. Absolute standardization was obtained through scintillation-beta-counting the ${\mathrm{I}}^{128}$ in NaI(Tl) crystals irradiated with a neutron source calibrated by the manganese bath technique.