  The sensitivity of neutrinoless double beta (0n2b) decay experiments is
mainly depended on the internal background of a detector which, in its turn, is
defined by the purity of material and possibility for selection of background
events. The AMoRE (Advanced Mo based Rare process Experiment) collaboration
plans to use 40Ca100MoO4 scintillation crystals as a detector for search of
0n2b decay of 100Mo isotope. A purpose of this paper is further investigation
of internal background of 40Ca100MoO4 scintillation elements with a low
background setup at YangYang underground laboratory. We present new approaches
for selection of background events from analyzing data and latest results of
measurements of intrinsic background of 40Ca100MoO4 crystals as an example of
new technique application.
