Gamma source definition and energy spectrum simulation for EJ-315 liquid scintillator

[2112419057 (yiteng Sun)]

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Description

Dear FLUKA Experts,

I am writing to seek your advice on a simulation I am working on. As a beginner in FLUKA, I am currently trying to model a detection setup where gamma sources (such as Cs-137 and Co-60) irradiate an EJ-315 deuterated liquid scintillator coupled with a PMT. My main goal is to obtain a simulated energy spectrum to compare with my experimental data.

For the source definition, I am currently using the BEAM card to set the specific gamma energies (e.g., 0.662 MeV for Cs-137). I have attached my current .inp file for your reference. Since I am still learning, I am not sure if this simplified approach is appropriate. Could you please take a quick look and let me know if this setup is acceptable, or advise on the recommended way to define such radioactive sources?

Additionally, to generate the final spectrum, I need to score the energy deposition in the scintillator. Since I am using a liquid scintillator, I am also wondering how to properly account for physical effects like the non-linear light yield (Birks’ quenching) and the PMT’s energy resolution. Could you give me some advice on whether these effects should be modeled directly within FLUKA, or if it is standard practice to handle them during offline post-processing?

Thank you very much for your patience and for helping a beginner. I truly appreciate your time and guidance.

Best regards,

Yiteng

Great Bay University

Input files

EJ_315.inp (2.9 KB)

[2112419057 (yiteng Sun)]

EJ_315.inp (2.2 KB) For co60 source,there is 2 peaks:1173 kev ,1332 kev.I can only set one in the beam card. I have noticed that someone else in the forum use ‘HI-PROBE’ card Z=27 and A=60.But i don’t know how to make the card works.Is there any better way to set the co60 source?My aim is to see the deposition energy spectrum in the ‘EJ315’ area.

[tlorenzo (Tommaso Lorenzon)]

Hello Yiteng Sun,
Thank you for your question. I am attaching some material that will be useful for setting up the simulation.

• FLUKA lecture on radioactive sources: a description of the setup needed to model isotopes as radioactive sources. I believe this is the most complete way to model your problem, rather than simulating single gamma lines.

• FLUKA offers a Birks’ laws implementation for dedicated scorings. I have selected some relevant topics from this forum:

  • https://fluka-forum.web.cern.ch/t/non-linear-electron-scintillation-efficiency-in-nai-tl-crystals/2042 and related links

  • https://fluka-forum.web.cern.ch/t/scintillation-simulation/1295

  • https://flukafiles.web.cern.ch/manual/chapters/description_input/description_options/tcquench.html

I hope this material provides you with a good starting point for your simulation.
Best regards,

Tommaso

[2112419057 (yiteng Sun)]

Dear Tommaso,

Many thanks to this important information,i’ll try this on later.

Yiteng