Status of the Integral/IBIS telescope modeling and of the response matrices generation

The main objective of the IBIS modeling activities is the generation of the IBIS spectral response matrices. This generation has been done step by step by firstly constructing a "calibrated model" of each IBIS sub-system. A "calibrated model" is defined as a GEANT Monte-Carlo model, further checked by intensive corresponding calibration. These calibrated models have been in a second step integrated in the whole IBIS Mass Model. This Mass Model has been checked then using the data obtained during the IBIS telescope calibration, the Payload Ground Calibration at ESA/ESTEC, and will be refined using In-flight calibration data acquired during the whole INTEGRAL mission. The different IBIS response matrices have been generated using the IBIS Mass Model. Here we will present a status of the Mass Model and of the response matrices generation, and show with the Crab pulsar calibration data that, with the new release of the spectral extraction software by ISDC, we will have a good IBIS/ISGRI response from 20 to 600 keV.