LivermorePolarized differential cross section calculation for the L1 shell

Hi! I’m using G4 to simulate the angular distribution of photoelectron from a polarized beam. And I’m checking the differential cross section vs. theta/phi. It looks fine for the K shell. But for L1 shell the distribution looks quite weird.

I have two questions:

  1. According to the physics manual and also after checking the source code of G4PhotoElectricAngularGeneratorPolarized, which gives the angular distribution of G4LivermorePolarizedPhotoElectric, it looks like the these two functions: DSigmaKshellGavrila1959() and DSigmaL1shellGavrila() are identical.
    But according to the reference paper: M. Gavrila, Phys.Rev, 1961, the differential cross section for L1 should be: d_sigma_L1 = 1/8 * screening_correction * d_sigma_K. This 1/8*screening_correction factors are missing in the G4 calculation.

  2. In sampling the angular distribution of photoelectron, the “$G4LEDATA/photoelectric_angular” dataset is used. According to the G4 webpage, the low energy dataset are mainly coming fro Livermore library (EADL-EEDL-EPDL) except the “photoelectric_angular”. What’s the source of this dataset?
    kShell.pdf (21.8 KB) L1shell.pdf (21.3 KB)
    Thanks in advance.
    -Qian LIU