Figure 10.11
γ-Ray spectrum for^60 Co.^
(a) Sodium iodide detector.
(b) Germanium semiconductor detector.
(Courtesy of G.A. Wells, Kingston University.)to 4°C, removal of the offending chemical or acceleration of the reaction to completion by heating are
possible ways of overcoming the phenomenon. Chemical quenching is brought about by chemical
interference with the scintillation energy transitions and is typically a problem with sulphur or oxygen
compounds. Removal of the interfering compound is the only answer. Colour quenching can be
overcome by bleaching the offending colour or exploiting a secondary scintillator to move the emission
peak clear of the absorption peak. Many laboratories now determine^3 H and^14 C