Base class to create a Material Scan of the detector geometry. More...

#include <MaterialScan.h>

Inheritance diagram for MaterialScan2D:

Classes
struct	ScanParams
	Helper struct to Store Parameters of a Scan. More...

Public Member Functions
	MaterialScan2D (TFile *rootFile, const std::string &name, const std::string &axisLabel, const ScanParams &params)
	Constructor.

bool	createNext (G4ThreeVector &origin, G4ThreeVector &direction) override
	Get the origin and direction for the next scan particle.

int	getNRays () const override
	Return the number of rays in this scan.

void	UserSteppingAction (const G4Step *step) override
	Record the material budget for each step of the particles.

std::string	getName () const
	Return the name of the scan.

Protected Member Functions
virtual void	getRay (G4ThreeVector &origin, G4ThreeVector &direction)=0
	Get the origin and direction for the next scan particle.

TH2D *	getHistogram (const std::string &name)
	get histogram for a given name, create if needed.

void	fillValue (const std::string &name, double value)
	Fill the recorded material budget into the corresponding histogram.

bool	checkStep (const G4Step *step)
	check for stuck tracks by looking at the step length

Protected Attributes
ScanParams	m_params
	Parameters for the scan.

double	m_curU
	Current value of the parametetr u.

double	m_stepU
	Stepsize for the parameter u.

double	m_curV
	Current value of the parametetr v.

double	m_stepV
	Stepsize for the parameter v.

double	m_curDepth
	Tracklength of the current Ray.

std::map< std::string, std::unique_ptr< TH2D > >	m_regions
	Map holding pointers to all created histograms.

TFile *	m_rootFile
	Pointer to the root file for the histograms.

std::string	m_name
	Name of the scan, will be prefixed to all histogram names.

std::string	m_axisLabel
	Labels for the coordinate axes.

Private Attributes
int	m_zeroSteps {0}
	Count the number of steps with (almost) zero length.

Static Private Attributes
static constexpr double	c_zeroTolerance = 1e-6
	maximum Step length to be considered zero

static constexpr int	c_maxZeroStepsNudge = 10
	maximum number of consecutive zero steps before nudging the track along

static constexpr int	c_maxZeroStepsKill = 20
	maximum number of consecutive zero steps before killing the track

Detailed Description

Base class to create a Material Scan of the detector geometry.

This class is used to record the Material budget encountered by a particle and provide origin and directions of all particles used for the scan.

Definition at line 80 of file MaterialScan.h.

Constructor & Destructor Documentation

◆ MaterialScan2D()

MaterialScan2D	(	TFile *	rootFile,
		const std::string &	name,
		const std::string &	axisLabel,
		const ScanParams &	params
	)

Constructor.

Parameters

rootFile	Pointer to the ROOTFile where the histograms will be stored.
name	Prefix to preprend to all Histograms
axisLabel	Labels for the histogram axes, separated by semicolon
params	Parameters for the scan

Definition at line 78 of file MaterialScan.cc.

                                                                                                                          :
  MaterialScanBase(rootFile, name, axisLabel), m_params(params), m_curDepth(0)
{
  //Sort the parameters accordingly
  if (m_params.minU > m_params.maxU) std::swap(m_params.minU, m_params.maxU);
  if (m_params.minV > m_params.maxV) std::swap(m_params.minV, m_params.maxV);
  //Calculate step size of the parameters
  m_stepU = (m_params.maxU - m_params.minU) / m_params.nU;
  m_stepV = (m_params.maxV - m_params.minV) / m_params.nV;
  //Set Start values
  m_curU  = m_params.minU - m_stepU / 2.;
  m_curV  = m_params.minV + m_stepV / 2.;
  //Convert max depth to G4 units
  m_params.maxDepth /= Unit::mm;
  //Sort the list of ignored materials so that we can use binary search
  std::sort(m_params.ignoredMaterials.begin(), m_params.ignoredMaterials.end());
}

Member Function Documentation

◆ checkStep()

bool checkStep ( const G4Step * step )

protectedinherited

check for stuck tracks by looking at the step length

Definition at line 44 of file MaterialScan.cc.

{
  double stlen = step->GetStepLength();
  G4StepPoint* preStepPoint = step->GetPreStepPoint();
  G4Region* region = preStepPoint->GetPhysicalVolume()->GetLogicalVolume()->GetRegion();
  if (stlen < c_zeroTolerance) {
    ++m_zeroSteps;
  } else {
    m_zeroSteps = 0;
  }
  if (m_zeroSteps > c_maxZeroStepsNudge) {
    if (m_zeroSteps > c_maxZeroStepsKill) {
      B2ERROR("Track is stuck at " << preStepPoint->GetPosition() << " in volume '"
              << preStepPoint->GetPhysicalVolume()->GetLogicalVolume()->GetName()
              << " (" << region->GetName() << "): "
              << m_zeroSteps << " consecutive steps with length less then "
              << c_zeroTolerance << " mm, killing it");
      step->GetTrack()->SetTrackStatus(fStopAndKill);
    } else {
      B2WARNING("Track is stuck at " << preStepPoint->GetPosition() << " in volume '"
                << preStepPoint->GetPhysicalVolume()->GetLogicalVolume()->GetName()
                << " (" << region->GetName() << "): "
                << m_zeroSteps << " consecutive steps with length less then "
                << c_zeroTolerance << " mm, nudging it along");
      G4ThreeVector pos = step->GetTrack()->GetPosition();
      G4ThreeVector dir = step->GetTrack()->GetMomentumDirection();
      step->GetTrack()->SetPosition(pos + c_zeroTolerance * dir);
    }
    return false;
  }
  return true;
}

◆ createNext()

bool createNext	(	G4ThreeVector &	origin,
		G4ThreeVector &	direction
	)

overridevirtual

Get the origin and direction for the next scan particle.

Parameters

[out]	origin	Origin of the next scan particle
[out]	direction	Direction of the next scan particle

Returns: false if the scan is finished

Implements MaterialScanBase.

Definition at line 97 of file MaterialScan.cc.

{
  if (m_regions.empty()) {
    // create summary histogram right now, not on demand, to make sure it is in the file
    if (m_params.splitByMaterials) {
      getHistogram("All_Materials_x0");
      getHistogram("All_Materials_lambda");
    } else {
      getHistogram("All_Regions_x0");
      getHistogram("All_Regions_lambda");
    }
  }
  //Increase the internal coordinates
  m_curU += m_stepU;
  if (m_curU >= m_params.maxU) {
    m_curU  = m_params.minU + m_stepU / 2.;
    m_curV += m_stepV;
  }
  //Reset depth counter
  m_curDepth = 0;
 
  //Get the origin and direction of the ray
  getRay(origin, direction);
 
  //Check wether we are finished
  return (m_curV <= m_params.maxV);
}

◆ fillValue()

void fillValue	(	const std::string &	name,
		double	value
	)

protected

Fill the recorded material budget into the corresponding histogram.

Parameters

name	Name of the histogram
value	Value to store

Definition at line 138 of file MaterialScan.cc.

{
  TH2D* hist = getHistogram(name);
  hist->Fill(m_curU, m_curV, value);
}

◆ getHistogram()

TH2D * getHistogram ( const std::string & name )

protected

get histogram for a given name, create if needed.

Parameters

name	Name of the histogram

Definition at line 125 of file MaterialScan.cc.

{
  std::unique_ptr<TH2D>& hist = m_regions[name];
  if (!hist) {
    //Create new histogram
    m_rootFile->cd(m_name.c_str());
    hist.reset(new TH2D(name.c_str(), (name + ";" + m_axisLabel).c_str(),
                        m_params.nU, m_params.minU, m_params.maxU,
                        m_params.nV, m_params.minV, m_params.maxV));
  }
  return hist.get();
}

◆ getName()

std::string getName ( ) const

inlineinherited

Return the name of the scan.

Definition at line 43 of file MaterialScan.h.

43{ return m_name; }

◆ getNRays()

int getNRays ( ) const

inlineoverridevirtual

Return the number of rays in this scan.

Implements MaterialScanBase.

Definition at line 122 of file MaterialScan.h.

122{ return m_params.nU * m_params.nV; }

◆ getRay()

virtual void getRay	(	G4ThreeVector &	origin,
		G4ThreeVector &	direction
	)

protectedpure virtual

Get the origin and direction for the next scan particle.

To be overridden by descendents

Parameters

[out]	origin	Origin of the next scan particle
[out]	direction	Direction of the next scan particle

Implemented in MaterialScanSpherical, and MaterialScanPlanar.

◆ UserSteppingAction()

void UserSteppingAction ( const G4Step * step )

override

Record the material budget for each step of the particles.

Definition at line 144 of file MaterialScan.cc.

{
  //Get information about radiation and interaction length
  G4StepPoint* preStepPoint = step->GetPreStepPoint();
  G4Region* region = preStepPoint->GetPhysicalVolume()->GetLogicalVolume()->GetRegion();
  G4Material* material = preStepPoint->GetMaterial();
  double stlen = step->GetStepLength();
  double x0 = stlen / (material->GetRadlen());
  double lambda = stlen / (material->GetNuclearInterLength());
  B2DEBUG(20, "Step in at " << preStepPoint->GetPosition() << " in volume '"
          << preStepPoint->GetPhysicalVolume()->GetLogicalVolume()->GetName()
          << " (" << region->GetName() << ")"
          << " with length=" << stlen << " mm");
  checkStep(step);
 
  //check if the depth is limited
  if (m_params.maxDepth > 0) {
    m_curDepth += stlen;
    if (m_curDepth > m_params.maxDepth) {
      //Depth reached, kill track and add remaining part of the material budget
      G4Track* track = step->GetTrack();
      track->SetTrackStatus(fStopAndKill);
      double remaining = stlen - m_curDepth + m_params.maxDepth;
      x0 *= remaining / stlen;
      lambda *= remaining / stlen;
    }
  }
 
  if (std::binary_search(m_params.ignoredMaterials.begin(), m_params.ignoredMaterials.end(), material->GetName())) {
    return;
  }
 
  //Fill x0 and lambda in a histogram for each region
  string x0_total = "All_Regions_x0";
  string lambda_total = "All_Regions_lambda";
  string x0_name = region->GetName() + "_x0";
  string lambda_name = region->GetName() + "_lambda";
  //or for each Material
  if (m_params.splitByMaterials) {
    x0_total = "All_Materials_x0";
    lambda_total = "All_Materials_lambda";
    x0_name = material->GetName() + "_x0";
    lambda_name = material->GetName() + "_lambda";
  }
  fillValue(x0_total, x0);
  fillValue(lambda_total, lambda);
  fillValue(x0_name, x0);
  fillValue(lambda_name, lambda);
}

Member Data Documentation

◆ c_maxZeroStepsKill

constexpr int c_maxZeroStepsKill = 20

staticconstexprprivateinherited

maximum number of consecutive zero steps before killing the track

Definition at line 71 of file MaterialScan.h.

◆ c_maxZeroStepsNudge

constexpr int c_maxZeroStepsNudge = 10

staticconstexprprivateinherited

maximum number of consecutive zero steps before nudging the track along

Definition at line 69 of file MaterialScan.h.

◆ c_zeroTolerance

constexpr double c_zeroTolerance = 1e-6

staticconstexprprivateinherited

maximum Step length to be considered zero

Definition at line 67 of file MaterialScan.h.

◆ m_axisLabel

std::string m_axisLabel

protectedinherited

Labels for the coordinate axes.

Definition at line 64 of file MaterialScan.h.

◆ m_curDepth

double m_curDepth

protected

Tracklength of the current Ray.

Definition at line 156 of file MaterialScan.h.

◆ m_curU

double m_curU

protected

Current value of the parametetr u.

Definition at line 148 of file MaterialScan.h.

◆ m_curV

double m_curV

protected

Current value of the parametetr v.

Definition at line 152 of file MaterialScan.h.

◆ m_name

std::string m_name

protectedinherited

Name of the scan, will be prefixed to all histogram names.

Definition at line 62 of file MaterialScan.h.

◆ m_params

ScanParams m_params

protected

Parameters for the scan.

Definition at line 146 of file MaterialScan.h.

◆ m_regions

std::map<std::string, std::unique_ptr<TH2D> > m_regions

protected

Map holding pointers to all created histograms.

Definition at line 158 of file MaterialScan.h.

◆ m_rootFile

TFile* m_rootFile

protectedinherited

Pointer to the root file for the histograms.

Definition at line 60 of file MaterialScan.h.

◆ m_stepU

double m_stepU

protected

Stepsize for the parameter u.

Definition at line 150 of file MaterialScan.h.

◆ m_stepV

double m_stepV

protected

Stepsize for the parameter v.

Definition at line 154 of file MaterialScan.h.

◆ m_zeroSteps

int m_zeroSteps {0}

privateinherited

Count the number of steps with (almost) zero length.

Definition at line 73 of file MaterialScan.h.

The documentation for this class was generated from the following files:

simulation/modules/include/MaterialScan.h
simulation/modules/src/MaterialScan.cc

Classes

Public Member Functions

Protected Member Functions

Protected Attributes

Private Attributes

Static Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ MaterialScan2D()

Member Function Documentation

◆ checkStep()

◆ createNext()

◆ fillValue()

◆ getHistogram()

◆ getName()

◆ getNRays()

◆ getRay()

◆ UserSteppingAction()

Member Data Documentation

◆ c_maxZeroStepsKill

◆ c_maxZeroStepsNudge

◆ c_zeroTolerance

◆ m_axisLabel

◆ m_curDepth

◆ m_curU

◆ m_curV

◆ m_name

◆ m_params

◆ m_regions

◆ m_rootFile

◆ m_stepU

◆ m_stepV

◆ m_zeroSteps