What is meaning of the fourth parameter "minEkin" the class G4UserLimits?

Geometry, Fields and Transportation
1

When i use the class G4UserLimits to limit the transport energy in some LogicVolume,
but the fourth parameter of the construtor G4UserLimits(100*cm,maxLength,maxTime,minEkin)
of the class seems to work weirdly,
what exacly meaning of this parameter?

  1. continue to transport below this energy?
    or 2.continue to transport largger than this energy, when the energy below this parameter, deposit the
    energy in this point?
    or something else?
2

Hi Siyuan1979,

I searched the Geant4 source code to try and find an answer to your question. You can see there are 16 instances of “userlimits” in the source code here: Repository search results · GitHub

From the G4MinEkineCuts class: geant4/source/physics_lists/constructors/limiters/src/G4MinEkineCuts.cc at 3dfcdb544e19888c7a5979720ae09596207436f2 · Geant4/geant4 · GitHub

if (eKine < eMin ) {
proposedStep = 0.;
}

It looks like if the kinetic energy of a particle drops below the minEkin set in your userlimits, that particle will no longer be tracked (and I assume its energy is deposited locally).

Joseph