Scoring method for Count vs. Energy deposited plot in certain region by specific particle

Dear FLUKA experts,

Is there a way that I can generate a Count vs. Energy deposited spectra for certain particles (4-He in this case) in certain region using the built-in scoring method?

I was using USRBDX to generate spectrum when 4-He passes the boundary, but that is not quite what I want. What I am trying to do is to figure out how much energy is deposited in the Argon gas by each 4-He particle when it passes through the gas.

The attached is my input file along with the neutron spectra.

Thanks for all the help in advance.

Martin

BNTN.inp (1.7 KB)
PuBe.txt (359 Bytes)

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Extra questions:

  1. I understand that the low energy neutron excludes the explicit production of charged particles, with Boron as one of the exceptions. When I examine the output file, I could see the production of alpha particles without any problem, but not 7-Lithium. Is there a way I could see how many 7-Lithium are created in the output file and possible to tally them?

  2. When I use USRBDX to tally the 4-He to produce a Current vs. Energy spectra, I found that the highest energy a produced 4-He can have is around 5 MeV. This is rather strange to me since the neutrons I used in this simulation only have the energy up to ~11 MeV. According to the equation shown below, the 4-He is not possible to have 5 MeV. Is there something wrong with my setup?
    image

You can consider EVENTBIN for event by event energy deposition scoring, coupled to AUXSCORE to apply the 4-HELIUM filter.
Otherwise, beyond built-in options, one shall code the appropriate logic in user routines such as comscw.f or mgdraw.f.

Extra answers:

  1. You can use the RESNUCLEi card.
    To properly transport them, lower down to the minimum the ion transport threshold, setting to 1 keV the 4-HELIUM threshold by means of the PART-THR card: this will apply to any HEAVYION (A>5) the same threshold in kinetic energy per nucleon, i.e. 250 eV/A. Ask also for full transport of all light and heavy ions (IONTRANS).
    This way you may be able to intercept them by USRBDX and similar scoring cards as you do for 4-HELIUM: they are identified as HEAVYION and the proper A and Z filter can be applied by an associated AUXSCORE card.

  2. Your equations consider a thermal neutron of 25 meV energy. If your neutrons reach 11 MeV, the reaction can occur at a well higher neutron energy and so benefit from a quite increased energy amount (up to 11 MeV more!), which becomes available to the reaction products.

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Dear @ceruttif,

Thank you so much for your detailed answers. Can’t wait to try it out.

Martin

Note that EVENTBIN, contrary to USRBIN, does not produce data ready to plot by Flair. Therefore, I suggest you ask for a formatted unit, in order to be able to immediately read them and set up a procedure of your own for processing them and obtaining the desired energy deposition spectrum (aka pulse height spectrum).

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Dear @ceruttif,

May I ask that what is the reason setting up PART-THR? How does this affect the transportation of the heavy charged ions in my setup?

Also, RESNUCLEi seems cannot be implemented in my simulation. The produced .err file suggest that activation of heavy fragment evaporation by means of the PHYSICS/EVAPORAT card is needed. Same message pops up even after I enabled the New Evap with heavy frag option with the PHYSICS card.

Thank you in advance.

Martin

If the threshold you set is lower than the ion energy (keeping in mind that A>5 ions take automatically the same threshold as 4-HELIUM in kinetic energy per nucleon and that the 4-HELIUM threshold has to be set in total kinetic energy, not per nucleon, with a hard limit at 1 keV), it enables more accurate ion transport, opposite to one step ranging out. This will not dramatically change the ion range, though.

The problem with your input is the unfortunate choice of the not recommended NEUTRONS DEFAULTS (well, we could suppress it forever), which turns out to inhibit by construction plenty of physics processes. Go with evergreen PRECISIOn instead, add the required PHYSICS card that at that point will succeed in enabling the most accurate evaporation model (… albeit practically not invoked for low energy neutron reactions), and you should make it with RESNUCLEi.

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Dear @ceruttif,

Thank you so much for pointing me in the right direction.

I opted in for the NEUTRONS DEFAULTS just cause I am doing low energy neutron transportation stuff, without knowing the construction of FLUKA behind the simulation.

Thanks again for your time.

Martin