I am new to FLUKA. I’m working on activation analysis of beamline components of a laser plasma accelerator which generates Very High Energy Electrons at femtosecond time scale. For this, I use a Source routine to read beam particles generated through PIC simulations with a weight assigned to each row. My query is while using IRRPROFI card I have to give pulses/sec, which is not relevant to my problem since the electrons are produced in femto second scale. What should be the input here and also should I give pulses with total weight (total charge) or only the number of primaries (number of rows in beam file)?
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Thank you for your question, and welcome to the forum!
I am not directly experienced with PIC simulations, but if I understand correctly, your source routine distributes electrons as primary particles within your irradiation geometry. These electrons originate from a PIC simulation carried out beforehand.
Regarding the IRRPROFI card: for an initial approximation, I suggest using an averaged irradiation profile. Try to estimate a representative “particles (or charge) per second” value and input that. I often do something similar when converting “particles per spill” (e.g., from proton accelerator data) into particles per second for use in the IRRPROFI card. This is generally good for activation studies. The level of detail needed in your profile depends on your specific requirements and simulation goals.
You also mentioned particle weights. When setting up your simulation, it’s crucial to distinguish between total charge per second (beam intensity), the number of primary events, and particle weights. Ensure that the weights from your PIC simulation are correctly implemented and consistent with your FLUKA simulation objectives.
Resources:
IRRPROFI:
Slides 21-23 of this lecture discuss considerations for irradiation profiles.
The IRRPROFI page on the manual is another key reference.
Several IRRPROFI cards can be issued in one input file to achieve a high level of detail. FLUKA processes these cards in sequence, from the first to the last.