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Energy loss loop

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This commit is contained in:
James Szalkie 2026-04-14 16:04:58 -04:00
parent 36b230d23a
commit 10a210cbab
2 changed files with 42 additions and 24 deletions
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2
Armory/ClassAnasen.h
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@ -113,7 +113,7 @@ inline void ANASEN::Construct3DModel(int anodeID1, int anodeID2, int cathodeID1,
TGeoMaterial *matAl = new TGeoMaterial("Al", 26.98,13,2.7);
TGeoMaterial *matSi = new TGeoMaterial("Si", 28.085,14,2.33);
//--- define some media
TGeoMedium *Vacuum = new TGeoMedium("Vacuum",1, matVacuum); //name, number of materials, material
//TGeoMedium *Vacuum = new TGeoMedium("Vacuum",1, matVacuum); //name, number of materials, material
TGeoMedium *He = new TGeoMedium("He",2, matHe);
TGeoMedium *Al = new TGeoMedium("Root Material",2, matAl);
TGeoMedium *Si = new TGeoMedium("Si",3, matSi);

62
Armory/anasenMS.cpp
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@ -33,21 +33,29 @@ int main(int argc, char **argv){
if( argc >= 2 ) numEvent = atoi(argv[1]);
// load energy loss tables (assume units: E in MeV, dE/dx in MeV/(mg/cm²), density in mg/cm³)
TGraph* elossLight = LoadELoss("../ELoss/Eloss_alpha"); // for light particle (alpha)
TGraph* elossLight = LoadELoss("../ELoss/Eloss_HeAlpha"); // for light particle (alpha)
TGraph* elossHeavy = LoadELoss("../ELoss/Eloss_p"); // for heavy particle (proton)
double density = 0.0000876; // example for aluminum target, adjust as needed
double density = 0.0000861; // example for aluminum target, adjust as needed
auto c1 = new TCanvas("c1", "Graph Example", 800, 600);
auto g = elossLight;
g->SetTitle("Energy Loss Table;Kinetic Energy (MeV);dE/dx (MeV/(mg/cm^{2}))");
g->Draw("ALP");
g->SetLineColor(kRed);
c1->SetLogy();
c1->SetLogx();
c1->Print("eloss_light.png");
auto g2 = elossHeavy;
g2->SetTitle("Energy Loss Table;Kinetic Energy (MeV);dE/dx (MeV/(mg/cm^{2}))");
g2->Draw("ALP");
g2->SetLineColor(kBlue);
c1->Print("eloss_heavy.png");
// Reaction setup: projectile + target configuration, energy, and product IDs
TransferReaction transfer;
transfer.SetA(24,12, 0); // e.g., 24Mg (Z=12) with 0 excitation
transfer.SetIncidentEnergyAngle(10, 0, 0); // 10 MeV beam, 0 polar and azimuthal angle
transfer.SetIncidentEnergyAngle(5.46, 0, 0); // 5.46 MeV beam, 0 polar and azimuthal angle
transfer.Seta( 4, 2); // identify reaction product a in internal indexing e.g., 4He (alpha)
transfer.Setb( 1, 1); // identify reaction product b e.g., 1H (proton)
@ -289,26 +297,36 @@ int main(int argc, char **argv){
z0 = pw->GetZ0();
tree->Fill();
//printf("Event %d: Tb before energy loss = %.2f MeV\n", i, Tb);
// apply energy loss from vertex to SX3 hit position (for light particle)
//Energy loss
double dl = (hitPos - vertex).Mag() / 10; // path length in cm (positions in mm)
//printf("Event %d: dl = %f cm\n", i, dl);
double EkinLight = Pb.E() - Pb.M();// kinetic energy of light particle before loss
double dedxLight = elossLight->Eval(EkinLight); // interpolate dE/dx
//printf("Event %d: dE/dx = %f MeV/(mg/cm^2)\n", i, dedxLight);
double dE_light = dedxLight * dl * density / 1000.0; // adjust for units (example scaling)
//printf("Event %d: dE_light = %f MeV\n", i, dE_light);
//if (dE_light < EkinLight) {
Pb.SetE(Pb.E() - dE_light); // update energy after loss
double p_new = TMath::Sqrt(Pb.E()*Pb.E() - Pb.M()*Pb.M()); // update momentum to conserve direction
TVector3 dir_new = Pb.Vect().Unit() * p_new; // maintain original direction, adjust magnitude
Pb.SetPxPyPzE(dir_new.X(), dir_new.Y(), dir_new.Z(), Pb.E()); // update 4-vector with new energy and momentum
//}
// update kinetic energy after loss
Tb = Tb - dE_light;
//double EkinLight = Pb.E() - Pb.M();// kinetic energy of light particle before loss
//double dedxLight = elossLight->Eval(EkinLight); // interpolate dE/dx
if (numEvent <= 10){
printf("Event %d: Ekin before loss = %f MeV, distance = %f cm\n", i, Tb, dl);
}
double tb_temp = Tb;
//double dE_light = dedxLight * dl * density / 1000.0; // adjust for units (example scaling)
double dx = 0;
double counter = 0;
while(dx < dl){
double step = 0.01; // cm, step size for energy loss calculation
if(dx + step > dl) step = dl - dx; // adjust last step to end at hit position
double EkinStep = Tb; // kinetic energy at current step
double dedxStep = elossLight->Eval(EkinStep); // dE/dx at current energy
double dE_step = dedxStep * step * density; // energy loss for this step
if (numEvent <= 10 && fmod(counter, 10) == 0){
printf("Event %d: step = %f, Ekin = %f MeV, dE/dx = %f MeV/(g/cm^2), dE_step = %f MeV\n", i, counter, EkinStep, dedxStep, dE_step);
}
Pb.SetE(Pb.E() - dE_step); // update energy after loss for this step
dx += step;
counter++;
Tb = Tb - dE_step; // update kinetic energy for tree storage
}
// fill tree2 with energy loss adjusted data
tree2->Fill();
//printf("Event %d: Tb after energy loss = %.2f MeV\n", i, Tb);
if (numEvent <= 10){
printf("Event %d: Tb after energy loss = %f MeV, energy loss = %f MeV\n", i, Tb, tb_temp - Tb);
}
}else{
// no valid SX3 hit: mark clearly invalid
@ -328,8 +346,8 @@ int main(int argc, char **argv){
z0 = TMath::QuietNaN();
// fill tree with original data (no energy loss for these events)
tree->Fill();
tree2->Fill();
//tree->Fill();
//tree2->Fill();
}
//#################################################################### Timer