The determination of the thermal neutron flux density by the measurement of the activities ratio Au-199/Au-198
Thermal neutrons produce isotopes of Au-198 and Au-199 in the two successive (n,y) reactions in irradiated gold. The ratio of their activities is proportional to the flux of the thermal neutrons, which was used for determination of the intensity of the flux. This method of determination of the flux of thermal neutrons is appropriate when the mass of the irradiated gold is not known. The comparison of the values of the flux of thermal neutrons obtained by this method and by the classical method of the activity measurement of Au-198 shows good agreement. (C) 2003 Elsevier Ltd. All rights reserved.