I have two queries regarding a simulation involving a proton beam incident on a Nickel target.
(a) While running this input, some of the runs stop midway with a TIMED-OUT error. However, this issue does not occur for smaller numbers of histories.
(b) In this simulation, the irradiated target contains residual activity. Is there a way to obtain the photon spectrum from this irradiated target (after a certain decay period) using the DETECT card, with the target placed in front of a NaI detector?
For this purpose, do I need to perform separate simulations for each radionuclide, assuming a uniform distribution throughout the target geometry, then normalize the spectra with respect to their activities and finally merge them?
Or, is there a way to perform this within the same input file?
a) the TIMED-OUT message from Flair does not necessarily imply an error: the run might still be ongoing. You shall look at the log and err files in the fluka_ temporary directory to learn more about the problem.
b) if you want the photon spectrum (number of photons as a function of photon energy), you should rather use USRTRACK, which can be associated to a cooling time.
This is not the case for DETECT, which gives an energy deposition spectrum (aka pulse height spectrum). To obtain the latter within the same input file, one can use RADDECAY in Semi-Analogue mode (forgetting about IRRPROFI, DCYTIMES and DCYSCORE), increase significantly the number of Replicas, and activate by USERWEIGHT a comscw.f of this kind (4.2 KB), where a cooling time interval filter is applied after taking into account the irradiation time. Results will be given per primary beam particle (but an acceptable statistical quality may be hard to achieve, in view of the time filter).