一、官网
是西欧核子研究组织(CERN)开发的全能粒子化学模拟器，可用于各类应用场合，包括核医学、高能化学、辐射防护等。
在官网上，你可以找到的最新版本和文档，以及广泛的应用示例和教程。的设计理念基于现代软件开发的最佳实践，并采用模块化结构，容许使用者依据须要选择特定模块，便于更好地适应其应用场合。
下边是一个简单的事例，展示怎样使用模拟一个简单的电子束：
#include "G4RunManager.hh"
#include "G4UImanager.hh"
#include "G4VisExecutive.hh"
#include "DetectorConstruction.hh"
#include "PhysicsList.hh"
#include "PrimaryGeneratorAction.hh"
int main(int argc, char** argv)
{
// Create the detector construction
DetectorConstruction* detector = new DetectorConstruction();
// Create the physics list
PhysicsList* physics = new PhysicsList();
// Create the primary generator action
PrimaryGeneratorAction* primary = new PrimaryGeneratorAction();
// Create the run manager and configure it
G4RunManager* runManager = new G4RunManager();
runManager->SetUserInitialization(detector);
runManager->SetUserInitialization(physics);
runManager->SetUserAction(primary);
// Initialize the Geant4 UI manager
G4UImanager* uiManager = G4UImanager::GetUIpointer();
// Initialize visualization
G4VisManager* visManager = new G4VisExecutive();
visManager->Initialize();
// Run in interactive mode
uiManager->ApplyCommand("/control/execute vis.mac");
// Clean up and exit
delete visManager;
delete runManager;
delete primary;
delete physics;
delete detector;
return 0;
}
二、学习资源
不仅官网上的资源物理实验模拟器电脑版，还有其他好多学习的资源。其中，grant是一个基于网路的远程桌面服务，提供一个访问的实验环境。
另外，的官网上也有一些教程，包括入门教程和中级教程。这种教程都提供源代码和示例数据，便捷用户学习。据悉，还有一些第三方机构和个人提供的课程材料和教学视频。
以下是官网上提供的一个简单的教程事例，展示怎样使用构建一个基本的侦测器和模拟一个质子束：
#include "G4RunManager.hh"
#include "G4UImanager.hh"
#include "G4UIterminal.hh"
#include "G4UItcsh.hh"
#include "G4VisExecutive.hh"
#include "G4UIExecutive.hh"
#include "DetectorConstruction.hh"
#include "PhysicsList.hh"
#include "PrimaryGeneratorAction.hh"
int main(int argc, char** argv)
{
// Create the run manager and configure it
G4RunManager* runManager = new G4RunManager();
runManager->SetUserInitialization(new DetectorConstruction());
runManager->SetUserInitialization(new PhysicsList());
runManager->SetUserAction(new PrimaryGeneratorAction());
// Initialize the Geant4 UI manager
G4UImanager* uiManager = G4UImanager::GetUIpointer();
// Initialize visualization
G4VisManager* visManager = new G4VisExecutive();
visManager->Initialize();
// Initialize the UI
G4UIExecutive* ui = new G4UIExecutive(argc, argv, "tcsh");
uiManager->ApplyCommand("/control/execute vis.mac");
ui->SessionStart();
// Clean up and exit
delete ui;
delete visManager;
delete runManager;
return 0;
}
三、设置通用粒子源
支持多种粒子源类型，包括单个粒子源、多个粒子源、泊松分布粒子源等。可以通过设置相应的源参数，控制粒子源的属性和生成数量。
以下是一个简单的事例，展示怎样使用构建一个基本的侦测器和模拟一个通用粒子源：
#include "G4RunManager.hh"
#include "G4UImanager.hh"
#include "G4VisExecutive.hh"
#include "DetectorConstruction.hh"
#include "PhysicsList.hh"
#include "PrimaryGeneratorAction.hh"
#include "GeneralParticleSource.hh"
int main(int argc, char** argv)
{
// Create the detector construction
DetectorConstruction* detector = new DetectorConstruction();
// Create the physics list
PhysicsList* physics = new PhysicsList();
// Create the primary generator action
PrimaryGeneratorAction* primary = new PrimaryGeneratorAction();
// Create the general particle source and configure it
GeneralParticleSource* gps = new GeneralParticleSource();
gps->SetParticleEnergy(1.0*GeV);
gps->SetParticleMomentumDirection(G4ThreeVector(0.,0.,1.));
gps->SetParticlePosition(G4ThreeVector(0.,0.,-10.));
// Set the GPS to be the primary generator action
primary->SetParticleSource(gps);
// Create the run manager and configure it
G4RunManager* runManager = new G4RunManager();
runManager->SetUserInitialization(detector);
runManager->SetUserInitialization(physics);
runManager->SetUserAction(primary);
// Initialize the Geant4 UI manager
G4UImanager* uiManager = G4UImanager::GetUIpointer();
// Initialize visualization
G4VisManager* visManager = new G4VisExecutive();
visManager->Initialize();
// Run in interactive mode
uiManager->ApplyCommand("/run/beamOn 100");
// Clean up and exit
delete visManager;
delete runManager;
delete primary;
delete physics;
delete detector;
return 0;
}
四、论坛
峰会是一个开放的社区，任何人都可以在这儿提出问题、分享经验和知识。峰会上有好多关于的讨论和技术支持，对于菜鸟和中级用户都很有用。
以下是峰会上的一个问题，关于怎么使用模拟一个粒子在材料中的运动轨迹：
// Use the Geant4 tracking manager to initialize the track
G4Track* track = new G4Track(new G4DynamicParticle(G4Proton::Proton(), G4ThreeVector(0.,0.,500.*MeV), 0.), 0., 0.);
G4TrackingManager* trackingManager = G4EventManager::GetEventManager()->GetTrackingManager();
trackingManager->SetStoreTrajectory(true);
trackingManager->SetTrajectory(new G4Trajectory(track));
trackingManager->ProcessOneTrack(track);
// Get the trajectory from the track and store it in a file
G4Trajectory* trajectory = (G4Trajectory*) track->GetUserInformation();
std::ofstream outFile("trajectory.txt");
for(int i=0; iGetPointEntries(); i++) {
G4TrajectoryPoint* point = (G4TrajectoryPoint*) trajectory->GetPoint(i);
outFile << point->GetPosition().x()/mm << " " << point->GetPosition().y()/mm << " " << point->GetPosition().z()/mm << std::endl;
}
outFile.close();
五、有时间概念吗？
支持时间模拟，可以记录粒子在模拟中经过的时间和抵达某个特定地点的时间。这对于个别应用场合十分重要，比如核医学和粒子化学学中的时间帧率。
以下是一个简单的事例，展示怎样使用模拟一个粒子在时间上的运动轨迹：
#include "G4RunManager.hh"
#include "G4UImanager.hh"
#include "G4VisExecutive.hh"
#include "DetectorConstruction.hh"
#include "PhysicsList.hh"
#include "PrimaryGeneratorAction.hh"
int main(int argc, char** argv)
{
// Create the detector construction
DetectorConstruction* detector = new DetectorConstruction();
// Create the physics list
PhysicsList* physics = new PhysicsList();
// Create the primary generator action
PrimaryGeneratorAction* primary = new PrimaryGeneratorAction();
// Create the run manager and configure it
G4RunManager* runManager = new G4RunManager();
runManager->SetUserInitialization(detector);
runManager->SetUserInitialization(physics);
runManager->SetUserAction(primary);
// Initialize the Geant4 UI manager
G4UImanager* uiManager = G4UImanager::GetUIpointer();
// Initialize visualization
G4VisManager* visManager = new G4VisExecutive();
visManager->Initialize();
// Run in interactive mode with time tracking
uiManager->ApplyCommand("/tracking/storeTrajectory 1");
uiManager->ApplyCommand("/run/beamOn 100");
// Clean up and exit
delete visManager;
delete runManager;
delete primary;
delete physics;
delete detector;
return 0;
}
结束语
是一个强悍的粒子化学模拟器，且用于各类应用场合。的学习曲线较崎岖物理实验模拟器电脑版，并且在把握相关技术后，可以帮助研究人员进行复杂的数学模拟，并为相关领域的研究提供支持。