Estimation of cross talk between lungs and liver for ²⁴¹Am using phoswich detector

²⁴¹Am is used as a tracer for in-vivo assessment of plutonium (Pu) in the lungs. Internal contamination of ²⁴¹Am is estimated by measuring its 59.5 keV photons then activity of Pu is estimated by applying Pu/²⁴¹Am ratio obtained from radiochemical analysis of fecal/workplace sample. According to ICRP systemic bio-kinetic model, for Type M compounds of ²⁴¹Am after 100 days post inhalation intake, ²⁴¹Am activity in liver exceeds ²⁴¹Am activity present in the lungs and goes on increasing even up to about ten years. In this work, cross talk (CT) between lungs and liver viz. CT (liver to lungs) and CT (lungs to liver) for the actinide monitoring system for ²⁴¹Am using realistic thorax Lawrence Livermore National Laboratory (LLNL) phantom were estimated. Also CT has been estimated using voxel phantom by carrying out Monte Carlo simulations in FLUKA code. This study will help in reporting the actual activity present in the individual organ (lungs, liver)