CONTRIBUTION TO 14-MEV NEUTRON ACTIVATION ANALYSIS USING HALF-LIVES BETWEEN 0.55 AND 873 MILLISECONDS

A study of the possibility of using half-lives between 0.55 and 873 msec in activation analysis with 14 MeV neutrons is presented here. The cyclic counting method is used: irradiation and detection are repeated several times and counts are memorised during all successive cycles until good final statistics are reached. The theoretical aspect of the cyclic counting method and the influence of neutron pulse shape on the activation results are discussed. The sample is activated and its activity measured in the same geometry: the sample and the scintillation detector are placed close to the target of the neutron generator. An electronic gating system is used to avoid photomultiplier gain fluctuations involved in neutron bombardment. Detection limits are measured for the following elements: Be, B, Al, Ca, As, Zr, In, Tl, Pb, Bi. © 1969 Akadémiai Kiadó.