68 lines
2.5 KiB
C++
68 lines
2.5 KiB
C++
#include "PrimaryGeneratorAction.hh"
|
|
|
|
#include "G4Box.hh"
|
|
#include "G4LogicalVolume.hh"
|
|
#include "G4LogicalVolumeStore.hh"
|
|
#include "G4ParticleDefinition.hh"
|
|
#include "G4ParticleGun.hh"
|
|
#include "G4ParticleTable.hh"
|
|
#include "G4RunManager.hh"
|
|
#include "G4SystemOfUnits.hh"
|
|
#include "Randomize.hh"
|
|
|
|
namespace B1 {
|
|
|
|
PrimaryGeneratorAction::PrimaryGeneratorAction() {
|
|
// 初始化粒子枪，每个 event 有 n_particle 个粒子
|
|
G4int n_particle = 1;
|
|
fParticleGun = new G4ParticleGun(n_particle);
|
|
|
|
// default particle kinematic
|
|
// 粒子列表的查找器
|
|
G4ParticleTable* particleTable = G4ParticleTable::GetParticleTable();
|
|
// 设置为 6 MeV 沿 z 轴正方向的 gamma 源
|
|
G4ParticleDefinition* particle = particleTable->FindParticle("gamma");
|
|
fParticleGun->SetParticleDefinition(particle);
|
|
fParticleGun->SetParticleMomentumDirection(G4ThreeVector(0., 0., 1.));
|
|
fParticleGun->SetParticleEnergy(6. * MeV);
|
|
}
|
|
|
|
PrimaryGeneratorAction::~PrimaryGeneratorAction() { delete fParticleGun; }
|
|
|
|
// 每次 event 调用一次 this function is called at the begining of ecah event
|
|
// 可以设置粒子能谱分布、角度分布、源的位置分布
|
|
void PrimaryGeneratorAction::GeneratePrimaries(G4Event* anEvent) {
|
|
G4double envSizeXY = 0;
|
|
G4double envSizeZ = 0;
|
|
|
|
// 避免引入 DetectorConstruction 类
|
|
// 从 G4LogicalVolumeStore 获取 Envelope volume
|
|
if (!fEnvelopeBox) {
|
|
G4LogicalVolume* envLV = G4LogicalVolumeStore::GetInstance()->GetVolume("Envelope");
|
|
if (envLV) fEnvelopeBox = dynamic_cast<G4Box*>(envLV->GetSolid());
|
|
}
|
|
|
|
// 获取几何参数
|
|
if (fEnvelopeBox) {
|
|
envSizeXY = fEnvelopeBox->GetXHalfLength() * 2.;
|
|
envSizeZ = fEnvelopeBox->GetZHalfLength() * 2.;
|
|
} else {
|
|
G4ExceptionDescription msg;
|
|
msg << "Envelope volume of box shape not found.\n";
|
|
msg << "Perhaps you have changed geometry.\n";
|
|
msg << "The gun will be place at the center.";
|
|
G4Exception("PrimaryGeneratorAction::GeneratePrimaries()", "MyCode0002", JustWarning, msg);
|
|
}
|
|
|
|
// 几何参数用于调整源的空间分布
|
|
G4double size = 0.8;
|
|
G4double x0 = size * envSizeXY * (G4UniformRand() - 0.5);
|
|
G4double y0 = size * envSizeXY * (G4UniformRand() - 0.5);
|
|
G4double z0 = -0.5 * envSizeZ;
|
|
|
|
fParticleGun->SetParticlePosition(G4ThreeVector(x0, y0, z0)); // 设置此次发射的位置
|
|
fParticleGun->GeneratePrimaryVertex(anEvent); // 发射粒子
|
|
}
|
|
|
|
} // namespace B1
|