Utility for expanding the PDF in y direction. More...

#include <YScanner.h>

Inheritance diagram for YScanner:

Classes
struct	Derivatives
	Derivatives. More...

struct	PixelProjection
	Down-stream projection of a pixel to prism entrance window w/ a clip on bar exit thickness. More...

struct	Result
	Single PDF peak data. More...

struct	Table
	A table of equidistant entries. More...

struct	TableEntry
	Table entry. More...

Public Types
enum	EGeometry { c_Unified = 0 , c_Segmented = 1 }
	Treatement of quartz geometry. More...

enum	EOptics { c_SemiLinear = 0 , c_Exact = 1 }
	Treatement of spherical mirror optics. More...

Public Member Functions
	YScanner (int moduleID, unsigned N=64)
	Class constructor.

void	clear () const
	Clear mutable variables.

void	prepare (double momentum, double beta, double length) const
	Prepare for the PDF expansion in y for a given track mass hypothesis.

bool	isAboveThreshold () const
	Returns above Cerenkov threshold flag which is set in the prepare method.

void	expand (unsigned col, double yB, double dydz, const Derivatives &D, int Ny, bool doScan) const
	Performs the PDF expansion in y for a given pixel column using scan or merge methods.

const PixelPositions &	getPixelPositions () const
	Returns pixel positions and their sizes.

const PixelMasks &	getPixelMasks () const
	Returns pixel masks.

const PixelEfficiencies &	getPixelEfficiencies () const
	Returns pixel relative efficiencies.

const Table &	getEfficiencies () const
	Returns nominal photon detection efficiencies (PDE)

double	getCosTotal () const
	Returns cosine of total reflection angle.

double	getMomentum () const
	Returns particle momentum.

double	getBeta () const
	Returns particle beta.

double	getTrackLengthInQuartz () const
	Returns particle trajectory lenght inside quartz.

double	getNumPhotonsPerLen () const
	Returns number of photons per Cerenkov azimuthal angle per track length.

double	getNumPhotons () const
	Returns number of photons per Cerenkov azimuthal angle.

double	getMeanEnergy () const
	Returns mean photon energy.

double	getRMSEnergy () const
	Returns r.m.s of photon energy.

double	getMeanEnergyBeta1 () const
	Returns mean photon energy for beta = 1.

double	getRMSEnergyBeta1 () const
	Returns r.m.s of photon energy for beta = 1.

double	getSigmaScattering () const
	Returns r.m.s of multiple scattering angle in quartz converted to photon energy.

double	getSigmaAlpha () const
	Returns surface roughness parameter in units of photon energy.

const Table &	getEnergyDistribution () const
	Returns photon energy distribution.

const std::map< int, Table >	getQuasyEnergyDistributions () const
	Returns photon energy distributions convoluted with multiple scattering and surface roughness.

const std::vector< Result > &	getResults () const
	Returns the results of PDF expansion in y.

bool	isScanDone () const
	Checks which expansion method was used.

int	getModuleID () const
	Returns slot ID.

EGeometry	getGeometry () const
	Returns quartz geometry treatement.

EOptics	getOptics () const
	Returns treatement of spherical mirror optics.

const std::vector< BarSegment > &	getBars () const
	Returns geometry data of bar segments.

const Mirror &	getMirror () const
	Returns geometry data of spherical mirror.

const Prism &	getPrism () const
	Returns geometry data of prism.

void	setMirrorCenter (double xc, double yc)
	Sets the mirror center-of-curvature.

Static Public Member Functions
static void	setScanLimits (int maxReflections)
	Sets parameters for selection between expand methods.

Protected Attributes
int	m_moduleID = 0
	slot ID

EGeometry	m_geometry = c_Unified
	quartz geometry

EOptics	m_optics = c_SemiLinear
	spherical mirror optics

std::vector< BarSegment >	m_bars
	geometry data of bar segments

Mirror	m_mirror
	spherical mirror geometry data

Prism	m_prism
	prism geometry data

Private Member Functions
double	setEnergyDistribution (double beta) const
	Sets photon energy distribution and mean photon energy according to nominal PDE and particle beta.

void	setQuasyEnergyDistribution (double sigma) const
	Sets photon energy distribution convoluted with a normalized Gaussian.

void	integrate (const EnergyMask *energyMask, double Ecp, Result &result) const
	Integrates quasy energy distribution multiplied with energy mask.

void	projectPixel (double yc, double size, int k, double dydz, PixelProjection proj[2]) const
	Calculates projections of a pixel to prism entrance window (going down-stream the photon).

void	scan (unsigned col, double yB, double dydz, const Derivatives &D, int j1, int j2) const
	Performs expansion w/ the scan over reflections.

void	merge (unsigned col, double dydz, int j1, int j2) const
	Performs expansion by merging all reflections.

PixelMasks &	pixelMasks ()
	Returns non-const pixel masks.

PixelEfficiencies &	pixelEfficiencies ()
	Returns non-const pixel relative efficiencies.

Private Attributes
PixelPositions	m_pixelPositions
	positions and sizes of pixels

PixelMasks	m_pixelMasks
	pixel masks

PixelEfficiencies	m_pixelEfficiencies
	pixel relative efficiencies

Table	m_efficiency
	nominal photon detection efficiencies (PDE)

double	m_meanE0 = 0
	mean photon energy for beta = 1

double	m_rmsE0 = 0
	r.m.s of photon energy for beta = 1

double	m_cosTotal = 0
	cosine of total reflection angle

double	m_momentum = 0
	particle momentum magnitude

double	m_beta = 0
	particle beta

double	m_length = 0
	length of particle trajectory inside quartz

double	m_numPhotons = 0
	number of photons per Cerenkov azimuthal angle per track length

double	m_meanE = 0
	mean photon energy

double	m_rmsE = 0
	r.m.s of photon energy

double	m_sigmaScat = 0
	r.m.s.

double	m_sigmaAlpha = 0
	surface roughness parameter in photon energy units

Table	m_energyDistribution
	photon energy distribution

std::map< int, Table >	m_quasyEnergyDistributions
	photon energy distributions convoluted with Gaussian of different widths

Table *	m_quasyEnergyDistribution = nullptr
	a pointer to the element in m_quasyEnergyDistributions

bool	m_aboveThreshold = false
	true if beta is above the Cerenkov threshold

std::vector< Result >	m_results
	results of PDF expansion in y

bool	m_scanDone = false
	true if scan performed, false if reflections just merged

Static Private Attributes
static int	s_maxReflections = 16
	maximal number of reflections to perform scan

Friends
class	TOPRecoManager

Detailed Description

Utility for expanding the PDF in y direction.

Definition at line 33 of file YScanner.h.

Member Enumeration Documentation

◆ EGeometry

enum EGeometry

inherited

Treatement of quartz geometry.

Enumerator
c_Unified	single bar with average width and thickness
c_Segmented	segmented bars

Definition at line 33 of file RaytracerBase.h.

                     {
        c_Unified = 0,   
        c_Segmented = 1  
      };

◆ EOptics

enum EOptics

inherited

Treatement of spherical mirror optics.

Enumerator
c_SemiLinear	semi-linear approximation
c_Exact	exact optics

Definition at line 41 of file RaytracerBase.h.

                   {
        c_SemiLinear = 0, 
        c_Exact = 1       
      };

Constructor & Destructor Documentation

◆ YScanner()

YScanner	(	int	moduleID,
		unsigned	N = `64`
	)

explicit

Class constructor.

Sets pixel positions of a given module and nominal photon detection efficiency.

Parameters

moduleID	slot ID
N	size of nominal photon detection efficiency table

Definition at line 47 of file YScanner.cc.

                                              : RaytracerBase(moduleID, c_Unified, c_SemiLinear),
      m_pixelPositions(PixelPositions(moduleID)),
      m_pixelMasks(PixelMasks(moduleID)),
      m_pixelEfficiencies(PixelEfficiencies(moduleID))
    {
      if (N < 2) {
        B2FATAL("TOP::YScanner: N must be > 1");
        return;
      }
 
      // set the table of nominal photon detection efficiencies (incl. wavelength filter)
 
      const auto* topgp = TOPGeometryPar::Instance();
      const auto* geo = topgp->getGeometry();
      auto qe = geo->getNominalQE(); // get a copy
      qe.applyFilterTransmission(geo->getWavelengthFilter());
 
      double minE = TOPGeometryPar::c_hc / qe.getMaxLambda();
      double maxE = TOPGeometryPar::c_hc / qe.getMinLambda();
      if (minE >= maxE) {
        B2FATAL("TOP::YScanner: quantum efficiency found zero for all wavelengths");
        return;
      }
      m_efficiency.set(minE, (maxE - minE) / (N - 1));
 
      const auto& tdc = geo->getNominalTDC();
      for (unsigned i = 0; i < N; i++) {
        double e = m_efficiency.getX(i);
        double lambda = TOPGeometryPar::c_hc / e;
        double effi = qe.getEfficiency(lambda) * tdc.getEfficiency();
        m_efficiency.entries.push_back(TableEntry(effi, e, e * e));
      }
 
      // set cosine of total reflection angle using photon mean energy for beta = 1
 
      double s = 0;
      double se = 0;
      double see = 0;
      for (const auto& entry : m_efficiency.entries) {
        double e = entry.x;
        double p = entry.y * (1 - 1 / pow(topgp->getPhaseIndex(e), 2));
        s += p;
        se += p * e;
        see += p * e * e;
      }
      if (s == 0) return;
      m_meanE0 = se / s;
      m_rmsE0 = sqrt(see / s - m_meanE0 * m_meanE0);
      m_cosTotal = sqrt(1 - 1 / pow(topgp->getPhaseIndex(m_meanE0), 2));
    }

Member Function Documentation

◆ clear()

void clear ( ) const

Clear mutable variables.

Definition at line 99 of file YScanner.cc.

    {
      m_momentum = 0;
      m_beta = 0;
      m_length = 0;
      m_numPhotons = 0;
      m_meanE = 0;
      m_rmsE = 0;
      m_sigmaScat = 0;
      m_sigmaAlpha = 0;
      m_energyDistribution.clear();
      m_quasyEnergyDistributions.clear();
      m_quasyEnergyDistribution = nullptr;
      m_aboveThreshold = false;
      m_results.clear();
      m_scanDone = false;
    }

◆ expand()

void expand	(	unsigned	col,
		double	yB,
		double	dydz,
		const Derivatives &	D,
		int	Ny,
		bool	doScan
	)		const

Performs the PDF expansion in y for a given pixel column using scan or merge methods.

Results accessable with getResults() method.

Parameters

col	pixel column number (0-based)
yB	unfolded coordinate y of photon at prism entrance (= Bar exit) plane
dydz	photon slope in y-z projection at prism entrance (dy/dz)
D	the derivatives
Ny	effective number of reflections
doScan	if true decide between scan and merge methods, if false always use merge method

Definition at line 238 of file YScanner.cc.

    {
      m_results.clear();
 
      if (D.dyB_de == 0) return;
 
      double sigma = sqrt(pow(m_sigmaScat, 2) + pow(m_sigmaAlpha, 2) * std::abs(Ny));
      setQuasyEnergyDistribution(sigma);
 
      double minE = m_quasyEnergyDistribution->getXmin();
      double maxE = m_quasyEnergyDistribution->getXmax();
      double pixDx  = m_pixelPositions.get(col + 1).Dx;
      double dely = (std::abs(D.dyB_dL) * m_length + std::abs(D.dyB_dx) * pixDx) / 2;
      double y1 = yB - dely;
      double y2 = yB + dely;
      if (D.dyB_de > 0) {
        y1 += D.dyB_de * (minE - m_meanE);
        y2 += D.dyB_de * (maxE - m_meanE);
      } else {
        y1 += D.dyB_de * (maxE - m_meanE);
        y2 += D.dyB_de * (minE - m_meanE);
      }
      double B = m_bars.front().B;
      int j1  = lround(y1 / B);
      int j2  = lround(y2 / B) + 1;
 
      if (doScan and j2 - j1 <= s_maxReflections) {
        scan(col, yB, dydz, D, j1, j2);
        m_scanDone = true;
      } else {
        merge(col, dydz, j1, j2);
        m_scanDone = false;
      }
    }

◆ getBars()

const std::vector< BarSegment > & getBars ( ) const

inlineinherited

Returns geometry data of bar segments.

Returns: geometry data of bar segments

Definition at line 161 of file RaytracerBase.h.

161{return m_bars;}

◆ getBeta()

double getBeta ( ) const

inline

Returns particle beta.

Returns: particle beta

Definition at line 305 of file YScanner.h.

305{return m_beta;}

◆ getCosTotal()

double getCosTotal ( ) const

inline

Returns cosine of total reflection angle.

Returns: cosine of total reflection angle at mean photon energy for beta = 1

Definition at line 293 of file YScanner.h.

293{return m_cosTotal;}

◆ getEfficiencies()

const Table & getEfficiencies ( ) const

inline

Returns nominal photon detection efficiencies (PDE)

Returns: nominal photon detection efficiencies

Definition at line 287 of file YScanner.h.

287{return m_efficiency;}

◆ getEnergyDistribution()

const Table & getEnergyDistribution ( ) const

inline

Returns photon energy distribution.

Returns: photon energy distribution

Definition at line 365 of file YScanner.h.

365{return m_energyDistribution;}

◆ getGeometry()

EGeometry getGeometry ( ) const

inlineinherited

Returns quartz geometry treatement.

Returns: quartz geometry treatement

Definition at line 149 of file RaytracerBase.h.

149{return m_geometry;}

Belle2::TOP::RaytracerBase::m_geometry

EGeometry m_geometry

quartz geometry

Definition: RaytracerBase.h:185

◆ getMeanEnergy()

double getMeanEnergy ( ) const

inline

Returns mean photon energy.

Returns: mean photon energy

Definition at line 329 of file YScanner.h.

329{return m_meanE;}

◆ getMeanEnergyBeta1()

double getMeanEnergyBeta1 ( ) const

inline

Returns mean photon energy for beta = 1.

Returns: mean photon energy for beta = 1

Definition at line 341 of file YScanner.h.

341{return m_meanE0;}

◆ getMirror()

const Mirror & getMirror ( ) const

inlineinherited

Returns geometry data of spherical mirror.

Returns: geometry data of spherical mirror

Definition at line 167 of file RaytracerBase.h.

167{return m_mirror;}

Belle2::TOP::RaytracerBase::m_mirror

Mirror m_mirror

spherical mirror geometry data

Definition: RaytracerBase.h:189

◆ getModuleID()

int getModuleID ( ) const

inlineinherited

Returns slot ID.

Returns: slot ID

Definition at line 143 of file RaytracerBase.h.

143{return m_moduleID;}

Belle2::TOP::RaytracerBase::m_moduleID

int m_moduleID

slot ID

Definition: RaytracerBase.h:184

◆ getMomentum()

double getMomentum ( ) const

inline

Returns particle momentum.

Returns: particle momentum

Definition at line 299 of file YScanner.h.

299{return m_momentum;}

◆ getNumPhotons()

double getNumPhotons ( ) const

inline

Returns number of photons per Cerenkov azimuthal angle.

Returns: number of photons per radian

Definition at line 323 of file YScanner.h.

323{return m_numPhotons * m_length;}

◆ getNumPhotonsPerLen()

double getNumPhotonsPerLen ( ) const

inline

Returns number of photons per Cerenkov azimuthal angle per track length.

Returns: number of photons per radian per centimeter

Definition at line 317 of file YScanner.h.

317{return m_numPhotons;}

◆ getOptics()

EOptics getOptics ( ) const

inlineinherited

Returns treatement of spherical mirror optics.

Returns: spherical mirror optics

Definition at line 155 of file RaytracerBase.h.

155{return m_optics;}

Belle2::TOP::RaytracerBase::m_optics

EOptics m_optics

spherical mirror optics

Definition: RaytracerBase.h:186

◆ getPixelEfficiencies()

const PixelEfficiencies & getPixelEfficiencies ( ) const

inline

Returns pixel relative efficiencies.

Returns: pixel relative efficiencies

Definition at line 281 of file YScanner.h.

281{return m_pixelEfficiencies;}

◆ getPixelMasks()

const PixelMasks & getPixelMasks ( ) const

inline

Returns pixel masks.

Returns: pixel masks

Definition at line 275 of file YScanner.h.

275{return m_pixelMasks;}

◆ getPixelPositions()

const PixelPositions & getPixelPositions ( ) const

inline

Returns pixel positions and their sizes.

Returns: pixel positions and their sizes in module local frame

Definition at line 269 of file YScanner.h.

269{return m_pixelPositions;}

◆ getPrism()

const Prism & getPrism ( ) const

inlineinherited

Returns geometry data of prism.

Returns: geometry data of prism

Definition at line 173 of file RaytracerBase.h.

173{return m_prism;}

Belle2::TOP::RaytracerBase::m_prism

Prism m_prism

prism geometry data

Definition: RaytracerBase.h:190

◆ getQuasyEnergyDistributions()

const std::map< int, Table > getQuasyEnergyDistributions ( ) const

inline

Returns photon energy distributions convoluted with multiple scattering and surface roughness.

Map entries correspond to different Gaussian widths due to different number of reflections.

Returns: photon energy distributions convoluted with multiple scattering and surface roughness

Definition at line 372 of file YScanner.h.

372{return m_quasyEnergyDistributions;}

◆ getResults()

const std::vector< Result > & getResults ( ) const

inline

Returns the results of PDF expansion in y.

Returns: results

Definition at line 378 of file YScanner.h.

378{return m_results;}

◆ getRMSEnergy()

double getRMSEnergy ( ) const

inline

Returns r.m.s of photon energy.

Returns: r.m.s of photon energy

Definition at line 335 of file YScanner.h.

335{return m_rmsE;}

◆ getRMSEnergyBeta1()

double getRMSEnergyBeta1 ( ) const

inline

Returns r.m.s of photon energy for beta = 1.

Returns: r.m.s of photon energy for beta = 1

Definition at line 347 of file YScanner.h.

347{return m_rmsE0;}

◆ getSigmaAlpha()

double getSigmaAlpha ( ) const

inline

Returns surface roughness parameter in units of photon energy.

Returns: surface roughness parameter [eV]

Definition at line 359 of file YScanner.h.

359{return m_sigmaAlpha;}

◆ getSigmaScattering()

double getSigmaScattering ( ) const

inline

Returns r.m.s of multiple scattering angle in quartz converted to photon energy.

Returns: r.m.s of multiple scattering angle in quartz [eV]

Definition at line 353 of file YScanner.h.

353{return m_sigmaScat;}

◆ getTrackLengthInQuartz()

double getTrackLengthInQuartz ( ) const

inline

Returns particle trajectory lenght inside quartz.

Returns: particle trajectory lenght inside quartz

Definition at line 311 of file YScanner.h.

311{return m_length;}

◆ integrate()

void integrate	(	const EnergyMask *	energyMask,
		double	Ecp,
		Result &	result
	)		const

private

Integrates quasy energy distribution multiplied with energy mask.

Parameters

energyMask	energy mask (pointer must be valid)
Ecp	position of the mask
result	updated result [in/out]

Definition at line 368 of file YScanner.cc.

    {
      const auto& mask = energyMask->getMask();
 
      if (mask.empty()) {
        // direct mask calculation
        for (size_t i = 0; i < m_quasyEnergyDistribution->entries.size(); i++) {
          double E = m_quasyEnergyDistribution->getX(i);
          double m = energyMask->getMask(E - Ecp);
          if (m > 0) {
            const auto& entry = m_quasyEnergyDistribution->entries[i];
            double s = entry.y * m;
            result.sum += s;
            result.e0 += entry.x * s;
            result.sigsq += entry.xsq * s;
          }
        }
      } else {
        // pre-calculated discrete mask w/ linear interpolation
        int i0 = m_quasyEnergyDistribution->getIndex(Ecp);
        double fract = -(Ecp - m_quasyEnergyDistribution->getX(i0)) / m_quasyEnergyDistribution->step;
        if (fract < 0) {
          i0++;
          fract += 1;
        }
        int N = m_quasyEnergyDistribution->entries.size() - 1;
        int M = mask.size() - 1;
        int i1 = std::max(i0 - M, 0);
        int i2 = std::min(i0 + M - 1, N);
        for (int i = i1; i <= i2; i++) {
          const auto& entry = m_quasyEnergyDistribution->entries[i];
          double m = mask[std::abs(i - i0)] * (1 - fract) + mask[std::abs(i - i0 + 1)] * fract;
          double s = entry.y * m;
          result.sum += s;
          result.e0 += entry.x * s;
          result.sigsq += entry.xsq * s;
        }
      }
    }

◆ isAboveThreshold()

bool isAboveThreshold ( ) const

inline

Returns above Cerenkov threshold flag which is set in the prepare method.

Returns: true, if beta is above the Cherenkov threshold for at least one PDE data point

Definition at line 251 of file YScanner.h.

251{return m_aboveThreshold;}

◆ isScanDone()

bool isScanDone ( ) const

inline

Checks which expansion method was used.

Returns: true if scan, false if merge

Definition at line 384 of file YScanner.h.

384{return m_scanDone;}

◆ merge()

void merge	(	unsigned	col,
		double	dydz,
		int	j1,
		int	j2
	)		const

private

Performs expansion by merging all reflections.

Parameters

col	pixel column number (0-based)
dydz	photon slope in y-z projection at prism entrance (dy/dz)
j1	first reflection number in y
j2	last (exclusive) reflection number in y

Definition at line 337 of file YScanner.cc.

    {
      int Neven = func::getNumOfEven(j1, j2);
      int Nodd = j2 - j1 - Neven;
 
      for (unsigned row = 0; row < m_pixelPositions.getNumPixelRows(); row++) {
 
        int pixelID = m_pixelPositions.pixelID(row, col);
        if (not m_pixelMasks.isActive(pixelID)) continue;
 
        const auto& pixel = m_pixelPositions.get(pixelID);
        double Dy0 = 0;
        double Dy1 = 0;
        PixelProjection proj[2];
        for (size_t k = 0; k < m_prism.unfoldedWindows.size(); k++) {
          projectPixel(pixel.yc, pixel.Dy, k, dydz, proj);
          if (proj[0].Dy > 0) Dy0 += proj[0].Dy;
          if (proj[1].Dy > 0) Dy1 += proj[1].Dy;
        }
        if (Dy0 == 0 and Dy1 == 0) continue;
 
        double Dy = (Dy0 * Neven + Dy1 * Nodd) / (Neven + Nodd);
        Result result(pixelID);
        result.sum = Dy / m_bars.front().B;
        result.e0 = m_meanE;
        result.sigsq = m_rmsE * m_rmsE;
        m_results.push_back(result);
      }
    }

◆ pixelEfficiencies()

PixelEfficiencies & pixelEfficiencies ( )

inlineprivate

Returns non-const pixel relative efficiencies.

Returns: pixel relative efficiencies

Definition at line 450 of file YScanner.h.

450{return m_pixelEfficiencies;}

◆ pixelMasks()

PixelMasks & pixelMasks ( )

inlineprivate

Returns non-const pixel masks.

Returns: pixel masks

Definition at line 444 of file YScanner.h.

444{return m_pixelMasks;}

◆ prepare()

void prepare	(	double	momentum,
		double	beta,
		double	length
	)		const

Prepare for the PDF expansion in y for a given track mass hypothesis.

Sets photon energy and quasy-energy distributions, mean and r.m.s of photon energy, number of photons and aboveThreshold flag.

Parameters

momentum	particle momentum
beta	particle beta
length	length of particle trajectory within the quartz

Definition at line 118 of file YScanner.cc.

    {
      clear();
 
      m_momentum = momentum;
      m_beta = beta;
      m_length = length;
 
      // check for Cherenkov threshold, return if below
 
      const auto* topgp = TOPGeometryPar::Instance();
      if (beta * topgp->getPhaseIndex(m_meanE0) < 1) return;
 
      // set photon energy distribution, and the mean and r.m.s of photon energy
 
      auto area = setEnergyDistribution(beta);
      if (area == 0) return;
 
      // set number of Cerenkov photons per azimuthal angle per centimeter
 
      m_numPhotons = 370 * area / (2 * M_PI);
 
      // set multiple scattering and surface roughness sigmas in photon energy units
 
      const double radLength = 12.3; // quartz radiation length [cm]
      double thetaScat = 13.6e-3 / beta / momentum * sqrt(length / 2 / radLength); // r.m.s of multiple scattering angle
 
      double n = topgp->getPhaseIndex(m_meanE);
      if (beta * n < 1) {
        B2ERROR("TOP::YScanner::prepare: beta * n < 1 ==> must be a bug!");
        return;
      }
      double dndE = topgp->getPhaseIndexDerivative(m_meanE);
      double dEdTheta = n * sqrt(pow(beta * n, 2) - 1) / dndE;
      m_sigmaScat = std::abs(thetaScat * dEdTheta); // r.m.s of multiple scattering angle converted to photon energy
      m_sigmaAlpha = std::abs(m_bars.back().sigmaAlpha * dEdTheta); // surface roughness converted to photon energy
 
      // set photon energy distribution convoluted with multiple scattering
 
      setQuasyEnergyDistribution(m_sigmaScat);
 
      m_aboveThreshold = true;
    }

◆ projectPixel()

void projectPixel	(	double	yc,
		double	size,
		int	k,
		double	dydz,
		PixelProjection	proj[2]
	)		const

private

Calculates projections of a pixel to prism entrance window (going down-stream the photon).

Parameters

yc	Pixel center in y.
size	Pixel size in y.
k	Valid index of vector of unfolded prism exit windows.
dydz	Photon slope at prism entrance; dydz is used for even projections and -dydz is used for odd projections.
proj	Projections of a pixel to prism entrance (results)

Definition at line 409 of file YScanner.cc.

    {
      double halfSize = (k - m_prism.k0) % 2 == 0 ? size / 2 : -size / 2;
      const double ypix[2] =  {yc - halfSize, yc + halfSize}; // pixel edges in y
      double yproj[2][2] = {{0}}; // pixel projections to prism entrance window (second index corresponds to pixel edges)
 
      const auto& win = m_prism.unfoldedWindows[k];
      double dz = std::abs(m_prism.zD - m_prism.zFlat);
      double projectedY = win.y0 + win.ny * dz;
      double projectedZ = win.z0 + win.nz * dz;
 
      #pragma omp simd
      for (int i = 0; i < 2; ++i) {
        /* Formerly YScanner::prismEntranceY. */
        double z = ypix[i] * win.sz + projectedZ;
        double y = ypix[i] * win.sy + projectedY;
        double dy = dydz * (m_prism.zR - z);
        yproj[0][i] = y + dy; // even reflections
        yproj[1][i] = y - dy; // odd reflections
      }
 
      double Bh = m_bars.front().B / 2;
      for (int i = 0; i < 2; ++i) {
        yproj[i][0] = std::max(yproj[i][0], -Bh);
        yproj[i][1] = std::min(yproj[i][1], Bh);
        proj[i].yc = (yproj[i][0] + yproj[i][1]) / 2;
        proj[i].Dy = yproj[i][1] - yproj[i][0];
      }
    }

◆ scan()

void scan	(	unsigned	col,
		double	yB,
		double	dydz,
		const Derivatives &	D,
		int	j1,
		int	j2
	)		const

private

Performs expansion w/ the scan over reflections.

Parameters

col	pixel column number (0-based)
yB	unfolded coordinate y of photon at prism entrance (= Bar exit) plane
dydz	photon slope in y-z projection at prism entrance (dy/dz)
D	the derivatives
j1	first reflection number in y
j2	last (exclusive) reflection number in y

Definition at line 274 of file YScanner.cc.

    {
 
      std::map<int, EnergyMask*> masks;
      for (unsigned row = 0; row < m_pixelPositions.getNumPixelRows(); row++) {
 
        int pixelID = m_pixelPositions.pixelID(row, col);
        if (not m_pixelMasks.isActive(pixelID)) continue;
 
        const auto& pixel = m_pixelPositions.get(pixelID);
        std::vector<PixelProjection> projections[2];
        PixelProjection proj[2];
        for (size_t k = 0; k < m_prism.unfoldedWindows.size(); k++) {
          projectPixel(pixel.yc, pixel.Dy, k, dydz, proj);
          if (proj[0].Dy > 0) projections[0].push_back(proj[0]);
          proj[1].yc = -proj[1].yc;
          if (proj[1].Dy > 0) projections[1].push_back(proj[1]);
        }
        if (projections[0].empty() and projections[1].empty()) continue;
 
        for (unsigned k = 0; k < 2; k++) {
          std::sort(projections[k].begin(), projections[k].end());
          for (auto& projection : projections[k]) {
            int iDy = lround(projection.Dy * 1000);
            auto& mask = masks[iDy];
            if (not mask) {
              double Dy = projection.Dy;
              double step = m_quasyEnergyDistribution->step;
              mask = new EnergyMask(D.dyB_de, D.dyB_dL, D.dyB_dx, Dy, m_length, pixel.Dx, step);
            }
            projection.mask = mask;
          }
        }
 
        double Ecp_old = 0;
        double wid_old = 1000;
        m_results.push_back(Result(pixelID));
        for (int j = j1; j < j2; j++) {
          double ybar = j * m_bars.front().B - yB;
          for (const auto& projection : projections[std::abs(j) % 2]) {
            double Ecp = (ybar + projection.yc) / D.dyB_de + m_meanE;
            double wid = projection.mask->getFullWidth();
            if (std::abs(Ecp - Ecp_old) > (wid + wid_old) / 2 and m_results.back().sum > 0) {
              m_results.push_back(Result(pixelID));
            }
            integrate(projection.mask, Ecp, m_results.back());
            Ecp_old = Ecp;
            wid_old = wid;
          }
        }
 
        if (m_results.back().sum == 0) m_results.pop_back();
      }
 
      for (auto& result : m_results) result.set();
 
      for (auto& mask : masks) {
        if (mask.second) delete mask.second;
      }
 
    }

◆ setEnergyDistribution()

double setEnergyDistribution ( double beta ) const

private

Sets photon energy distribution and mean photon energy according to nominal PDE and particle beta.

Parameters

beta	particle beta

Returns: integral of distribution before normalization

Definition at line 163 of file YScanner.cc.

    {
      const auto* topgp = TOPGeometryPar::Instance();
 
      m_energyDistribution.set(m_efficiency);
 
      double s = 0;
      double se = 0;
      double see = 0;
      for (const auto& entry : m_efficiency.entries) {
        double e = entry.x;
        double p = std::max(entry.y * (1 - 1 / pow(beta * topgp->getPhaseIndex(e), 2)), 0.0);
        double ee = entry.xsq;
        m_energyDistribution.entries.push_back(TableEntry(p, e, ee));
        s += p;
        se += p * e;
        see += p * ee;
      }
      if (s == 0) return 0;
 
      for (auto& entry : m_energyDistribution.entries) entry.y /= s;
 
      m_meanE = se / s;
      m_rmsE = sqrt(std::max(see / s - m_meanE * m_meanE, 0.0));
 
      return s * m_energyDistribution.step;
    }

◆ setMirrorCenter()

void setMirrorCenter	(	double	xc,
		double	yc
	)

inherited

Sets the mirror center-of-curvature.

Parameters

xc	center of curvature in x
yc	center of curvature in y

Definition at line 100 of file RaytracerBase.cc.

    {
      m_mirror.xc = xc;
      m_mirror.yc = yc;
 
      double zc = m_mirror.zc;
      double R = m_mirror.R;
      double zb = zc + R;
      double Ah = m_bars.back().A / 2;
      double Bh = m_bars.back().B / 2;
      zb = std::min(zb, zc + sqrt(pow(R, 2) - pow(xc - Ah, 2) - pow(yc - Bh, 2)));
      zb = std::min(zb, zc + sqrt(pow(R, 2) - pow(xc + Ah, 2) - pow(yc - Bh, 2)));
      zb = std::min(zb, zc + sqrt(pow(R, 2) - pow(xc - Ah, 2) - pow(yc + Bh, 2)));
      zb = std::min(zb, zc + sqrt(pow(R, 2) - pow(xc + Ah, 2) - pow(yc + Bh, 2)));
      m_mirror.zb = zb;
    }

◆ setQuasyEnergyDistribution()

void setQuasyEnergyDistribution ( double sigma ) const

private

Sets photon energy distribution convoluted with a normalized Gaussian.

Parameters

sigma width of the Gaussian [eV]

Definition at line 192 of file YScanner.cc.

    {
      if (m_quasyEnergyDistributions.size() > 1000) {
        m_quasyEnergyDistributions.clear();
        B2ERROR("TOP::YScanner:setQuasyEnergyDistribution: unexpectedly large size of the std::map found, map cleared");
      }
 
      double step = m_energyDistribution.step;
      int ng = lround(3 * sigma / step);
      auto& quasyEnergyDistribution = m_quasyEnergyDistributions[ng];
 
      if (quasyEnergyDistribution.entries.empty()) {
        std::vector<double> gaus;
        for (int i = 0; i <= ng; i++) {
          double x = step * i / sigma;
          gaus.push_back(exp(-0.5 * x * x));
        }
 
        quasyEnergyDistribution.set(m_energyDistribution.getX(-ng), step);
        int N = m_energyDistribution.entries.size();
        double sum = 0;
        for (int k = -ng; k < N + ng; k++) {
          double s = 0;
          double se = 0;
          double see = 0;
          for (int i = -ng; i <= ng; i++) {
            double p = gaus[std::abs(i)] * m_energyDistribution.getY(k - i);
            double e = m_energyDistribution.getX(k - i);
            s += p;
            se += p * e;
            see += p * e * e;
          }
          if (s > 0) {
            se /= s;
            see /= s;
          }
          quasyEnergyDistribution.entries.push_back(TableEntry(s, se, see));
          sum += s;
        }
        for (auto& entry : quasyEnergyDistribution.entries) entry.y /= sum;
      }
 
      m_quasyEnergyDistribution = &quasyEnergyDistribution;
    }

◆ setScanLimits()

static void setScanLimits ( int maxReflections )

inlinestatic

Sets parameters for selection between expand methods.

Parameters

maxReflections maximal number of reflections in y to perform scan

Definition at line 227 of file YScanner.h.

      {
        s_maxReflections = maxReflections;
      }

Friends And Related Function Documentation

◆ TOPRecoManager

friend class TOPRecoManager

friend

Definition at line 482 of file YScanner.h.

Member Data Documentation

◆ m_aboveThreshold

bool m_aboveThreshold = false

mutableprivate

true if beta is above the Cerenkov threshold

Definition at line 474 of file YScanner.h.

◆ m_bars

std::vector<BarSegment> m_bars

protectedinherited

geometry data of bar segments

Definition at line 188 of file RaytracerBase.h.

◆ m_beta

double m_beta = 0

mutableprivate

particle beta

Definition at line 463 of file YScanner.h.

◆ m_cosTotal

double m_cosTotal = 0

private

cosine of total reflection angle

Definition at line 459 of file YScanner.h.

◆ m_efficiency

Table m_efficiency

private

nominal photon detection efficiencies (PDE)

Definition at line 456 of file YScanner.h.

◆ m_energyDistribution

Table m_energyDistribution

mutableprivate

photon energy distribution

Definition at line 470 of file YScanner.h.

◆ m_geometry

EGeometry m_geometry = c_Unified

protectedinherited

quartz geometry

Definition at line 185 of file RaytracerBase.h.

◆ m_length

double m_length = 0

mutableprivate

length of particle trajectory inside quartz

Definition at line 464 of file YScanner.h.

◆ m_meanE

double m_meanE = 0

mutableprivate

mean photon energy

Definition at line 466 of file YScanner.h.

◆ m_meanE0

double m_meanE0 = 0

private

mean photon energy for beta = 1

Definition at line 457 of file YScanner.h.

◆ m_mirror

Mirror m_mirror

protectedinherited

spherical mirror geometry data

Definition at line 189 of file RaytracerBase.h.

◆ m_moduleID

int m_moduleID = 0

protectedinherited

slot ID

Definition at line 184 of file RaytracerBase.h.

◆ m_momentum

double m_momentum = 0

mutableprivate

particle momentum magnitude

Definition at line 462 of file YScanner.h.

◆ m_numPhotons

double m_numPhotons = 0

mutableprivate

number of photons per Cerenkov azimuthal angle per track length

Definition at line 465 of file YScanner.h.

◆ m_optics

EOptics m_optics = c_SemiLinear

protectedinherited

spherical mirror optics

Definition at line 186 of file RaytracerBase.h.

◆ m_pixelEfficiencies

PixelEfficiencies m_pixelEfficiencies

private

pixel relative efficiencies

Definition at line 455 of file YScanner.h.

◆ m_pixelMasks

PixelMasks m_pixelMasks

private

pixel masks

Definition at line 454 of file YScanner.h.

◆ m_pixelPositions

PixelPositions m_pixelPositions

private

positions and sizes of pixels

Definition at line 453 of file YScanner.h.

◆ m_prism

Prism m_prism

protectedinherited

prism geometry data

Definition at line 190 of file RaytracerBase.h.

◆ m_quasyEnergyDistribution

Table* m_quasyEnergyDistribution = nullptr

mutableprivate

a pointer to the element in m_quasyEnergyDistributions

Definition at line 473 of file YScanner.h.

◆ m_quasyEnergyDistributions

std::map<int, Table> m_quasyEnergyDistributions

mutableprivate

photon energy distributions convoluted with Gaussian of different widths

Definition at line 472 of file YScanner.h.

◆ m_results

std::vector<Result> m_results

mutableprivate

results of PDF expansion in y

Definition at line 477 of file YScanner.h.

◆ m_rmsE

double m_rmsE = 0

mutableprivate

r.m.s of photon energy

Definition at line 467 of file YScanner.h.

◆ m_rmsE0

double m_rmsE0 = 0

private

r.m.s of photon energy for beta = 1

Definition at line 458 of file YScanner.h.

◆ m_scanDone

bool m_scanDone = false

mutableprivate

true if scan performed, false if reflections just merged

Definition at line 478 of file YScanner.h.

◆ m_sigmaAlpha

double m_sigmaAlpha = 0

mutableprivate

surface roughness parameter in photon energy units

Definition at line 469 of file YScanner.h.

◆ m_sigmaScat

double m_sigmaScat = 0

mutableprivate

r.m.s.

of multiple scattering angle in photon energy units

Definition at line 468 of file YScanner.h.

◆ s_maxReflections

int s_maxReflections = 16

staticprivate

maximal number of reflections to perform scan

Definition at line 480 of file YScanner.h.

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

top/reconstruction_cpp/include/YScanner.h
top/reconstruction_cpp/src/YScanner.cc

Classes

Public Types

Public Member Functions

Static Public Member Functions

Protected Attributes

Private Member Functions

Private Attributes

Static Private Attributes

Friends

Detailed Description

Member Enumeration Documentation

◆ EGeometry

◆ EOptics

Constructor & Destructor Documentation

◆ YScanner()

Member Function Documentation

◆ clear()

◆ expand()

◆ getBars()

◆ getBeta()

◆ getCosTotal()

◆ getEfficiencies()

◆ getEnergyDistribution()

◆ getGeometry()

◆ getMeanEnergy()

◆ getMeanEnergyBeta1()

◆ getMirror()

◆ getModuleID()

◆ getMomentum()

◆ getNumPhotons()

◆ getNumPhotonsPerLen()

◆ getOptics()

◆ getPixelEfficiencies()

◆ getPixelMasks()

◆ getPixelPositions()

◆ getPrism()

◆ getQuasyEnergyDistributions()

◆ getResults()

◆ getRMSEnergy()

◆ getRMSEnergyBeta1()

◆ getSigmaAlpha()

◆ getSigmaScattering()

◆ getTrackLengthInQuartz()

◆ integrate()

◆ isAboveThreshold()

◆ isScanDone()

◆ merge()

◆ pixelEfficiencies()

◆ pixelMasks()

◆ prepare()

◆ projectPixel()

◆ scan()

◆ setEnergyDistribution()

◆ setMirrorCenter()

◆ setQuasyEnergyDistribution()

◆ setScanLimits()

Friends And Related Function Documentation

◆ TOPRecoManager

Member Data Documentation

◆ m_aboveThreshold

◆ m_bars

◆ m_beta

◆ m_cosTotal

◆ m_efficiency

◆ m_energyDistribution

◆ m_geometry

◆ m_length

◆ m_meanE

◆ m_meanE0

◆ m_mirror

◆ m_moduleID

◆ m_momentum

◆ m_numPhotons

◆ m_optics

◆ m_pixelEfficiencies

◆ m_pixelMasks

◆ m_pixelPositions

◆ m_prism

◆ m_quasyEnergyDistribution

◆ m_quasyEnergyDistributions