Dear FLUKA experts,
I am trying to simulate a spectrum of X-rays produced by bremsstrahlung of primary protons injected into a thick-target. A very simple plane-parallel geometry is considered in the simulation, which consists of a cubic box centered at the origin of a Cartesian coordinate system (Ox,Oy,Oz) with faces perpendicular to the coordinate axes. The z-coordinate corresponds to the vertical depth in the target. A xy-plane at z = 0 divides the cubic box into two half-spaces. The half-space at z < 0 is just filled with vacuum. The half-space at z > 0 is filled with atomic Hydrogen. The primary protons are injected into the z >0 region from a point located in the z <0 at a distance very close to the xy-plane at z = 0, and are assumed to have a downward isotropic angular distribution and a power-law energy distribution of spectral index delta = 4 in the range from 1 MeV to 1 GeV. Two USRBDX detectors are used to score the downward and upward current of photons escaping the target.
I am using the PAIRBREM card to set a 10 keV photon energy threshold for explicit bremsstrahlung production and several cards to suppress the contributions from processes other than the bremsstrahlung of protons. However, no photons are produced in the simulation. I would be grateful if you could check the setup of the simulation and for any help to understand what is causing this issue.
Attached are the project and input files and the routine source.f used to generate the energy and angular distributions of primary protons.
Cheers,
Sergio Szpigel
source.f (15.5 KB)
test.flair (3.3 KB)
test.inp (2.8 KB)