Metal-Loading Liquid Organic Scintillators for Recording Rare Events:
 Light Yield at High Metal Concentration

Metal-loading liquid organic scintillators (MeLS) are discussed from the point of view of light yield at high metal loading (Gd, Nd, Zr, In). It is shown that, when metal β-diketonates are introduced into the scintillator, its light yield is always lower than when carboxylates are used, which is explained by the structural difference between these complexes. The nature of the metal in some cases (Nd) also affectsthe light attenuation length and, consequently, the MeLS light yield. The composition of the solvent (the fraction of aromatics in the main solvent) and the degree of purification of the introduced metal complex also have a significant effect on the light yield.