Files
minicalosim/src/SteppingAction.cc
T
lars 9ea0718139 add Spawning ntuple recording secondary births per step
Each step that spawns secondaries now writes one row per secondary to a
new Spawning ntuple (event_id, parent_track_id, parent_step_no,
child_track_id). This enables direct shower-tree reconstruction without
position joins. Requires the companion Geant4 submodule change that
pre-assigns track IDs in ProcessSecondariesFromParticleChange.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-06-11 10:25:08 +02:00

177 lines
7.3 KiB
C++

//
// ********************************************************************
// * License and Disclaimer *
// * *
// * The Geant4 software is copyright of the Copyright Holders of *
// * the Geant4 Collaboration. It is provided under the terms and *
// * conditions of the Geant4 Software License, included in the file *
// * LICENSE and available at http://cern.ch/geant4/license . These *
// * include a list of copyright holders. *
// * *
// * Neither the authors of this software system, nor their employing *
// * institutes,nor the agencies providing financial support for this *
// * work make any representation or warranty, express or implied, *
// * regarding this software system or assume any liability for its *
// * use. Please see the license in the file LICENSE and URL above *
// * for the full disclaimer and the limitation of liability. *
// * *
// * This code implementation is the result of the scientific and *
// * technical work of the GEANT4 collaboration. *
// * By using, copying, modifying or distributing the software (or *
// * any work based on the software) you agree to acknowledge its *
// * use in resulting scientific publications, and indicate your *
// * acceptance of all terms of the Geant4 Software license. *
// ********************************************************************
//
//
/// \file B4/B4a/src/SteppingAction.cc
/// \brief Implementation of the B4a::SteppingAction class
#include "SteppingAction.hh"
#include "EventAction.hh"
#include "DetectorConstruction.hh"
#include "G4Step.hh"
#include "G4RunManager.hh"
#include "G4AnalysisManager.hh"
#include "G4Track.hh"
#include "G4ParticleDefinition.hh"
#include "G4TransportationManager.hh"
#include "G4FieldManager.hh"
#include "G4Field.hh"
#include "G4SystemOfUnits.hh"
using namespace B4;
namespace B4a
{
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
SteppingAction::SteppingAction(EventAction* eventAction)
: fEventAction(eventAction)
{}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
void SteppingAction::UserSteppingAction(const G4Step* step)
{
// Collect energy and track length step by step
// get volume of the current step
auto volume = step->GetPreStepPoint()->GetTouchableHandle()->GetVolume();
// energy deposit
auto edep = step->GetTotalEnergyDeposit();
//return;
//find the layer through the GeometryDescriptor that corresponds to the volume
auto cw = DetectorConstruction::getDetectorConstruction()->getGeometryDescriptor();
if(cw == nullptr){
G4cout << "GeometryDescriptor not found" << G4endl;
throw std::runtime_error("GeometryDescriptor not found");
}
auto sensor = DetectorConstruction::getDetectorConstruction()->getGeometryDescriptor()->getSensorByVolume(volume);
if(sensor != nullptr){
//G4cout << "Sensor found in " << volume->GetName() << " with copy number " << volume->GetCopyNo()<< G4endl; //DEBUG
sensor->energy += edep;
}
// Record step kinematics for every step
auto analysisManager = G4AnalysisManager::Instance();
auto pre = step->GetPreStepPoint();
auto post = step->GetPostStepPoint();
auto track = step->GetTrack();
int evtId = G4RunManager::GetRunManager()->GetCurrentEvent()->GetEventID();
// Write one Spawning row per secondary born in this step (track IDs pre-assigned)
const auto* secondaries = step->GetSecondaryInCurrentStep();
if (secondaries) {
for (const G4Track* sec : *secondaries) {
analysisManager->FillNtupleIColumn(2, 0, evtId);
analysisManager->FillNtupleIColumn(2, 1, track->GetTrackID());
analysisManager->FillNtupleIColumn(2, 2, track->GetCurrentStepNumber());
analysisManager->FillNtupleIColumn(2, 3, sec->GetTrackID());
analysisManager->AddNtupleRow(2);
}
}
analysisManager->FillNtupleIColumn(1, 0, evtId);
analysisManager->FillNtupleIColumn(1, 1, track->GetTrackID());
analysisManager->FillNtupleIColumn(1, 2, track->GetCurrentStepNumber());
analysisManager->FillNtupleIColumn(1, 3, track->GetDefinition()->GetPDGEncoding());
analysisManager->FillNtupleDColumn(1, 4, pre->GetPosition().x());
analysisManager->FillNtupleDColumn(1, 5, pre->GetPosition().y());
analysisManager->FillNtupleDColumn(1, 6, pre->GetPosition().z());
analysisManager->FillNtupleDColumn(1, 7, pre->GetKineticEnergy());
analysisManager->FillNtupleDColumn(1, 8, post->GetPosition().x());
analysisManager->FillNtupleDColumn(1, 9, post->GetPosition().y());
analysisManager->FillNtupleDColumn(1, 10, post->GetPosition().z());
analysisManager->FillNtupleDColumn(1, 11, post->GetKineticEnergy());
// A: energy deposited in medium at this step (≠ pre_E - post_E when secondaries are created)
analysisManager->FillNtupleDColumn(1, 12, edep);
// B: geometric step length
analysisManager->FillNtupleDColumn(1, 13, step->GetStepLength());
// C: parent track ID (0 for primary)
analysisManager->FillNtupleIColumn(1, 14, track->GetParentID());
// D: process that ended this step
G4String processName = "";
const auto* postProc = post->GetProcessDefinedStep();
if (postProc) processName = postProc->GetProcessName();
analysisManager->FillNtupleSColumn(1, 15, processName);
// E: layer index (-1 if outside all layers) and material name at pre-step point
int layerId = -1;
const auto& layers = cw->getLayers();
for (int i = 0; i < (int)layers.size(); i++) {
if (layers[i].physicalVolume == volume) { layerId = i; break; }
}
G4String materialName = pre->GetMaterial() ? pre->GetMaterial()->GetName() : "";
analysisManager->FillNtupleIColumn(1, 16, layerId);
analysisManager->FillNtupleSColumn(1, 17, materialName);
// F: pre-step momentum direction (unit vector)
const auto dir = pre->GetMomentumDirection();
analysisManager->FillNtupleDColumn(1, 18, dir.x());
analysisManager->FillNtupleDColumn(1, 19, dir.y());
analysisManager->FillNtupleDColumn(1, 20, dir.z());
// Field: B [T] and E [V/m] at pre-step position; zero if no field is registered
G4double Bx=0, By=0, Bz=0, Ex=0, Ey=0, Ez=0;
const auto* fm = G4TransportationManager::GetTransportationManager()->GetFieldManager();
if (fm && fm->DoesFieldExist()) {
const G4Field* field = fm->GetDetectorField();
if (field) {
const G4double point[4] = {pre->GetPosition().x(), pre->GetPosition().y(),
pre->GetPosition().z(), pre->GetGlobalTime()};
G4double fieldVal[6] = {0,0,0,0,0,0};
field->GetFieldValue(point, fieldVal);
Bx = fieldVal[0] / tesla;
By = fieldVal[1] / tesla;
Bz = fieldVal[2] / tesla;
Ex = fieldVal[3] / (volt/m);
Ey = fieldVal[4] / (volt/m);
Ez = fieldVal[5] / (volt/m);
}
}
analysisManager->FillNtupleDColumn(1, 21, Bx);
analysisManager->FillNtupleDColumn(1, 22, By);
analysisManager->FillNtupleDColumn(1, 23, Bz);
analysisManager->FillNtupleDColumn(1, 24, Ex);
analysisManager->FillNtupleDColumn(1, 25, Ey);
analysisManager->FillNtupleDColumn(1, 26, Ez);
analysisManager->AddNtupleRow(1);
}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
}