How can I add voltage on both edges of the material?

Dear FLUKA experts

I need to simulate an Imaging Detector called GEMini. This requires the ionization reaction of 6MeV photons with rare gases to generate electrons. At the same time, a voltage will be added at both ends of the material to trigger a Townsend avalanche. Finally, I will score the electron fluence at different positions to finish the greyscale figure.
However, The ELCFIELD card could only be used in the vacuum region. Could you teach me how to implement the voltage function?
Here are my .inp and .flair files
Gemini.flair (5.9 KB)
Gemini.inp (4.7 KB)
, and I am looking forward to your instruction.

Best regards
C-RAD GEMini 20170418-19.pdf (1.1 MB)

Hello @Sixue.Dong ,

If I understand correctly you would like to see the charge multiplication process by scoring the electron fluence at different locations. Your reasoning is that the generated electrons by interaction of radiation with the gas atoms/molecules receive high kinetic energies as a result of the applied potential.

Unfortunately this is not possible in FLUKA since, as you indicate, the ELCFIELD card can only be used in vacuum and not in a region filled with any material. The desired multiplication process can therefore not take place.

I believe in your case the use of FLUKA is limited to calculating the deposited energy inside the gas volume. Then you need to convert the amount of deposited energy into a generated amount of charges by knowing how much energy is required to create and electron-ion pair. The amplification process in turn needs an external model or software to calculate the resulting amount of electrons.

I nevertheless hope this answer helps, let us know if you need any other information.


Dear Andreas
Sincerely thank you for your answer, I will try other ways to achieve the simulation of GEMini.

Best regards