Abstract
The paper discusses a photoactivation method for determining the activity of the long-lived isotope \({}^{41}\) Ca relative to the activity of \({}^{60}\) Co in irradiated reactor biological shielding concrete. It is proposed to use photonuclear reactions on cobalt and calcium isotopes: \({}^{59}\) Co( \(\gamma\) , \(n\) ) \({}^{58}\) Co, \({}^{44}\) Ca( \(\gamma\) , \(p\) ) \({}^{43}\) K, or \({}^{48}\) Ca( \(\gamma\) , \(n\) ) \({}^{47}\) Ca \(\rightarrow\) \({}^{47}\) Sc to determine the activity of \({}^{41}\) Ca. The sensitivity of the proposed method is on the order of \({\sim}10^{-6}\) Bq/g, provided that semiconductor spectrometers with an ultrapure germanium detector are used. The structure and chemical compositions of the sample do not affect the proposed method. It avoids the long sample preparation times associated with radiochemical methods.
