A pulsed neutron source and a tank are described in my input file. My goal is to create a pulsed source that emits twice per cycle (100us emit, 100us cool, 50us emit).
According to the manuals, the particle_age function in the source.f file is used, but it cannot satisfy the requirement and could only generate one pulse.
How can I get a multi-emitting pulse source?
Bonus question: Using the RADDECAY card in semi-analogue mode, how do I record the inelastic gamma, capture gamma and activation gamma from a pulsed source?
Before building a complex irradiation profile, for activation studies I would suggest you to evaluate whether that level of detail is really needed.
Probably, in your case, if you want to assess the activation of your component after a given number of irradiation cycles, you could simply specify in the IRRPROFI card the average
beam intensity [primaries/s] for the time of your irradiation [s], without modeling the actual pulses one by one. Then you can separately assess the prompt photon radiation and the residual photon radiation coming from activation at different time intervals by specifying your cool-down times of interest (using the DCYTIMES card).
Attached you can find an example of this (the numbers I used in the irradiation profile are arbitrary, please change them according to your case).
Let me know if this does not help you with your problem,
Cheers,
Marco
I need to evaluate the count percentage of activated rays produced by the previous pulse in the later pulse time period. In my case, I need to record both the gamma counts generated by the previous 100us activated nucleus in the end moment of the second pulse and the inelastic and captured gamma counts in the end moment of the second pulse.
Semi-Analogue mode is used in RADDECAY, but I found that the two results don’t match in time and counts.
while I try to figure out a better way, have you tried splitting your problem into two simulations?
A first simulation in which you evaluate the prompt gamma fluence due to one pulse and a second one in which you evaluate the residual gamma fluence produced by one pulse at the point in time when your second pulse ends. In this way you should be able to compare prompt gamma fluence from the second pulse and delayed gamma fluence from the previous pulse. For the residual fluence you should use RADDECAY card: Activation and DCYTIMES card with the needed delta time (which, if I understood correctly your problem, should be 150 us).
The two results cannot be compared directly because, in your case, the output of the residual fluence scorer is given as photons/cm^2/s while the results of the prompt fluence scorer are in photons/cm^2/primary. What you still need in order to compare the two fluences is the intensity of your prompt source within the pulse, in the form of primary/s; in this way you can normalize your prompt results to have them expressed in photons/cm^2/s.
To confirm my understanding, for example, the intensity of the source is 10000Bq, I need to multiply the prompt source result by 10000 which to compare the residual source result?
Yes, although if I uderstood correctly, you have a source term, and not a decaying isotope, therefore its intensity should be better expressed in terms of primaries/s. By doing so you normalize the prompt FLUKA result by the source intensity.