Scoring Particles

New in version 3.70.0

Plane Crossing scorers

It is possible to score all particles crossing a plane surface inside the geometry setup.

An infinite plane is defined by a reference point (the origin O) and a normal vector n.

The pxs: directive is used to setup a plane crossing scorer:

ID = (int)

number identifying the scorer for subsequent output

O = [0, 0, 0]

Origin of the plane.

n = [0,0,1]

normal vector to the plane.

prec = (int) 6

floating point precision of text output

Hereafter an example of scoring particles crossing planes downstream of a field: this setup can be used to quickly check the beam propagation:

field: 1 ; O = [0,0,-200]; L=[40,40,1]; pivot = [0.5,0.5,0.5]

pb: 1 1 ; particle = proton; T = 100; sigmaSqrModel = [200,0.3328,-0.00128,3.2e-05,0.555556,0.00222222,2.22222e-05]

# define crossing planes along the beam axis
pxs: 1; O=[0,0, -20]; n=[0,0,1]; prec = 10
pxs: 2; O=[0,0,   0]; n=[0,0,1]; prec = 10
pxs: 3; O=[0,0, +20]; n=[0,0,1]; prec = 10

deactivate: phantom

nprim=1e4

Each plane will produce a separate file in the output directory

out/
└─ score
    ├─ PlaneCrossing_1.txt
    ├─ PlaneCrossing_2.txt
    ├─ PlaneCrossing_3.txt
    ├─ PlaneCrossing_4.txt
    └─ PlaneCrossing_5.txt

with all crossing events recorded by FRED, e.g.

# UID  PDGcode  gen x y z (cm)    cosx cosy cosz     energy (MeV)
1767 2212 1 0.2931099832 0.09622633457 -20 0.004025272559 0.005532842129 0.9999765158 100
2040 2212 1 -0.02017699182 -0.7830485702 -20 -0.0005401616218 -0.002020265441 0.9999977946 100
3326 2212 1 0.4653390348 -0.2075468302 -20 -0.005163567141 -0.0006195059977 0.9999864697 100
7875 2212 1 -0.6917120218 0.9977480173 -20 -0.000552367419 -0.006716909818 0.9999772906 100
6010 2212 1 0.7778751254 0.5707585216 -20 -0.001501463703 0.006481928751 0.9999778867 100
8917 2212 1 -0.5082454085 -0.1271313429 -20 0.007672127336 -0.002481081756 0.9999674559 100
...

where each rows corresponds to a crossing event, and a header line describes the columns. For instance, here we have the particle UID, the PDG code of the particle (2212=proton), its generation (1=primary), the hit position in global coords, the particle direction in global coords, and finally its kinetic energy.

Particle distribution along beam axis at selected planes around ISO centre.