Space resolution and relative scintillation efficiency of gamma imaging detector

Laser wake field accelerator is hopeful to become a new minitype gamma source. This type of source has excellent performance characteristics such as high energy, high brightness, small focal spot and ultra shot pulse export. Bremsstrahlung spectra produced by high wake field accelerated electron incident on high Z target is calculated by Monte-Carlo toolkit Geant4, and relative scintillation efficiency and point spread function of several gamma detecting crystal are calculated in the range of bremsstrahlung spectra. The relations between crystal thickness, crystal materials, incident gamma energy and the calculated results are analysed. All these provide important guidance for designing gamma detector in future．