How to calculate air kerma in Geant4?

Hello,

I am using Geant4 to simulate an X-ray imaging system, and I would like to calculate the air kerma at the detector entrance surface.

The X-ray source is a polychromatic X-ray spectrum, and I need to use the simulated air kerma to calibrate the number of photons emitted by the source against an experimentally measured air kerma.

I understand that Geant4 does not seem to provide a standard kerma scorer. What is the recommended way to calculate air kerma in Geant4 for a polychromatic X-ray beam?

Should I calculate it from the photon fluence and the mass energy-transfer coefficient of air, or can I obtain it by scoring the energy transferred to secondary electrons in an air volume?

Thank you for your help.

Geant4 Version: 10.07


Hello,

I found this paper by looking it up. See whether it takes you in the right direction

https://www.sciencedirect.com/science/article/pii/S135044870800334X

Cheers,

/Pico