Point detectors in MAVRIC / Monaco

[David Holler]

Hi,

How exactly are point detector tallies calculated in Monaco? The manual section just describes sampling techniques. I'm curious if there is a small assumed volume or some other parameter introduced to calculate flux. Thanks.

[Cihangir]

David,

Contribution to point detectors is based on probability of scattering a particle to a given point detector location after each collision as well as probability of reaching the point detector without making any collisions. So, distance and direction of each particle to point detector locations are calculated and probabilities of particle-scatterings based on each material/nuclide to each tally energy bin are accumulated throughout the simulation. There is no assumed volume surrounding the point detector. There is, however, a user parameter called "minSampProb" that controls how often contributions to a given point detector should be made based on particle weight (default is set to make contributions after every collisions, minSampProb=1). I don't recommend changing the default value if you are not sure what to do with it since it can bias your results.

Cheers,

Cihangir

[David Holler]

That's understandable. I had thought there would be a zero probability of a particle reaching a single point in space, but it sounds like it is low, not zero.