Particle Matter interaction and Large Angle scattering
A 249 MeV proton beam is hitting a degrader
REAL WEDGE_HLEN=0.0197293; REAL START = 0.02;
DEGPHYS_Wedge : SURFACEPHYSICS, TYPE="DEGRADER", MATERIAL="GraphiteR6710";
Wedge1: DEGRADER, L=WEDGE_HLEN, OUTFN="sWedge1.h5", SURFACEPHYSICS=DEGPHYS_Wedge, ELEMEDGE=START;
The claim is that the following transverse real space
and transverse momenta space
is not correct.
Switching off the large angle scattering (http://amas.web.psi.ch/docs/opal/opal_user_guide.pdf 18.2.2) the "halo" is disappearing, as shown by the red dots in the following picture:
Switch off == omment out: https://gitlab.psi.ch/OPAL/src/blob/master/src/Classic/Solvers/CollimatorPhysics.cpp#L777 and https://gitlab.psi.ch/OPAL/src/blob/master/src/Classic/Solvers/CollimatorPhysics.cpp#L746
Now we can enable/disable Rutherford scattering
DEGPHYS_Wedge : SURFACEPHYSICS, TYPE="DEGRADER", MATERIAL="GraphiteR6710", ENABLERUTHERFORD=TRUE;
Default is ENABLED
Be aware of the fact this inout file runs only with OPAL-1.6 (git checkout OPAL-1.6) sDegrader_70.in