Sensitivities of JEM-X

The mask design for JEM-X is now finalized regarding the hole pattern and m echnical support structure. The engineering model of the detectors with col limators is under construction. The JEM-X sensitivities for source detectio n in various circumstances are reviewed with proper regard to the way INTEG RAL will carry out its pointed observations. An important fraction of the I NTEGRAL observation time will be used for scans along the galactic plane an d observations of the central region of our galaxy. The JEM-X performance f or this type of observations is discussed. The software tools used to carry out the detailed observation simulations a re described.