anddecay
times wereestimatedbyfittingtheresults.Emissionspectrawere
recorded under a-particle excitation(241Am), usingthesame
FLS920 spectrofluorometer.Therelativelightyieldstrengthunder
excitation bythe 241Am radioisotopewascalculatedfromthe
pulse heightspectrummeasuredusingaphotomultipliertube
(see detailsin [11]). Thepulseheightspectrumforthestandard
Li-glass (6000photons/neutron)wasusedasreference.Allthe
measurementswerecarriedoutatroomtemperature.