Concept of the Si/CdTe Compton Camera Si -> Scatterer, CdTe->Absorber Si(Z=14) Low Photo Abs. High Compton Scattering CdTe(Z=48, 52 ρ~5.8 g/cm 3 ) High Photo Abs. High Energy Resolution Low Energy Threshold Good Position Resolution several 10 keV — MeV Gamma-rays DSSD(double-sided Silicon strip detector) 20-30 layers CdTe Pixel Detectors Symmetrically Placed 4-5 cm NeXT mission (JAXA, 201?)