Energy Dependence of HBT Measurements for Charged Pions at RHIC-PHENIX

HBT measurements are a sensitive probe for the space-time extent of the hot and dense systems produced in heavy-ion collisions. New HBT measurements have been recently obtained for charged pion pairs in the Au+Au collisions at $\sqrt {{s_{NN}}} $ = 39, 62.4 and 200 GeV with the PHENIX detector. These measurements will be presented with an emphasis on the scaling of HBT measurements with charged particle multiplicity. The results will also be compared to the results from hydrodynamical models.