Sum peak method applied to the study of human platelet cells

Study of nuclear quadrupole interactions in different environments of decaying atoms of 75Se by sum peak method

The sum peak intensity I400 (279 + 121 keV) relative to its singles peak intensity I279 or I121 has been determined in various environments of 75Se by gamma-gamma summing technique in a single HPGe detector. The change in intensity has been used to determine nuclear quadrupole interaction frequencies and electric field gradient components in different environments, e.g. Se-glycerol, Se-hydrochloric acid (HCl), Se-perchloric acid (HClO4), Se-blood samples with and without anti-coagulant, Se-alanine and Se-cysteine at different pH values. The electric field gradient is found to vary with chemical complex formation.

Application of the sum peak method to determine the perturbed angular correlation parameters in biological specimens

The counting rate of a sum peak formed by two gamma-ray emissions in radioactive decay of a nuclide depends on its integral attenuation factor G22. Therefore, in the "sum peak method", the G22 value for the specimen in question can be obtained merely from sum peak measurements using one radiation detector when the resolution time and the geometry are fixed. The procedure to determine the G22 values is described for specimens containing 111In, together with the detailed relationships between the sum peak counting rates and the values of G22.