I would like to simulate a fast timing setup consisting of LaBr3(Ce) scintillators, as shown in the figure. My purpose is to measure life times of some nuclear excited states (more generally B(E2) systematics) using coincidence, which are usually in the order of ps. So far I have learned about how to use voxels to record the energy deposited with the help of EVENTBIN and then use Birks factor to count the number of photons. My question is that is this achiaveable with FLUKA? How can one obtain excited state life times with FLUKA? How should I modify the mdraw.f and would it be more feasible to use GEANT4 instead?
Thank you. I would like to add a few things. To find life times, it seems prompt curve and delayed curve determination is crucial. I believe for this purpose I have to know the time stamps of each event, and then by using appropriate time bins I can save the number of events corresponding to each time stamp. How can one achieve this?
looking into more details into your request of simulation, I reached a critical aspect: in FLUKA, the gamma coming from the de-excitation of a nucleus is emitted instantly (without delays). Therefore I don’t think is possible to retrieve from the results of a simulation the information you are interested in.
On another side, the life of a nucleus’ exited state is known a priori, and if it is not, it surely cannot be obtained from a simulation.
If you still want to reproduce in FLUKA the experimental setup, you can use as source of your simulation an isomer of a specific isotope with the ISOTOPE entry in the BEAM card associated with HI-PROPE where WHAT(3) represents the isomeric state you are interested in. You can find some references on the forum and on the manual. I also suggest to have a look to the course slide to correctly set up a radioactive isotope as source.
Generally for the scoring, coincidence capability are included in the DETECT card. It will need to be correctly set once defined which signals are you looking for.
Otherwise, the gamma generated from the de-excitation of the isomer could be intercepted and scored through the use of the mgdraw.f routine.
