/**************************************************************************
* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
* *
* Author: The ALICE Off-line Project. *
* Contributors are mentioned in the code where appropriate. *
* *
* Permission to use, copy, modify and distribute this software and its *
* documentation strictly for non-commercial purposes is hereby granted *
* without fee, provided that the above copyright notice appears in all *
* copies and that both the copyright notice and this permission notice *
* appear in the supporting documentation. The authors make no claims *
* about the suitability of this software for any purpose. It is *
* provided "as is" without express or implied warranty. *
**************************************************************************/
/* $Id$ */
///////////////////////////////////////////////////////////////////////////////
// //
// Transition Radiation Detector version 1 -- slow simulator //
// //
//Begin_Html
/*
*/
//End_Html
// //
// //
///////////////////////////////////////////////////////////////////////////////
#include
#include
#include
#include
#include
#include
#include
#include "AliConst.h"
#include "AliLog.h"
#include "AliMC.h"
#include "AliRun.h"
#include "AliTRDgeometry.h"
#include "AliTRDhit.h"
#include "AliTRDsim.h"
#include "AliTRDv1.h"
ClassImp(AliTRDv1)
//_____________________________________________________________________________
AliTRDv1::AliTRDv1():AliTRD()
{
//
// Default constructor
//
fSensSelect = 0;
fSensPlane = -1;
fSensChamber = -1;
fSensSector = -1;
fSensSectorRange = 0;
fDeltaE = NULL;
fDeltaG = NULL;
fTR = NULL;
fStepSize = 0.1;
fTypeOfStepManager = 2;
}
//_____________________________________________________________________________
AliTRDv1::AliTRDv1(const char *name, const char *title)
:AliTRD(name, title)
{
//
// Standard constructor for Transition Radiation Detector version 1
//
fSensSelect = 0;
fSensPlane = -1;
fSensChamber = -1;
fSensSector = -1;
fSensSectorRange = 0;
fDeltaE = NULL;
fDeltaG = NULL;
fTR = NULL;
fStepSize = 0.1;
fTypeOfStepManager = 2;
SetBufferSize(128000);
}
//_____________________________________________________________________________
AliTRDv1::AliTRDv1(const AliTRDv1 &trd):AliTRD(trd)
{
//
// Copy constructor
//
((AliTRDv1 &) trd).Copy(*this);
}
//_____________________________________________________________________________
AliTRDv1::~AliTRDv1()
{
//
// AliTRDv1 destructor
//
if (fDeltaE) delete fDeltaE;
if (fDeltaG) delete fDeltaG;
if (fTR) delete fTR;
}
//_____________________________________________________________________________
AliTRDv1 &AliTRDv1::operator=(const AliTRDv1 &trd)
{
//
// Assignment operator
//
if (this != &trd) ((AliTRDv1 &) trd).Copy(*this);
return *this;
}
//_____________________________________________________________________________
void AliTRDv1::Copy(TObject &trd) const
{
//
// Copy function
//
((AliTRDv1 &) trd).fSensSelect = fSensSelect;
((AliTRDv1 &) trd).fSensPlane = fSensPlane;
((AliTRDv1 &) trd).fSensChamber = fSensChamber;
((AliTRDv1 &) trd).fSensSector = fSensSector;
((AliTRDv1 &) trd).fSensSectorRange = fSensSectorRange;
((AliTRDv1 &) trd).fTypeOfStepManager = fTypeOfStepManager;
((AliTRDv1 &) trd).fStepSize = fStepSize;
fDeltaE->Copy(*((AliTRDv1 &) trd).fDeltaE);
fDeltaG->Copy(*((AliTRDv1 &) trd).fDeltaG);
fTR->Copy(*((AliTRDv1 &) trd).fTR);
}
//_____________________________________________________________________________
void AliTRDv1::CreateGeometry()
{
//
// Create the GEANT geometry for the Transition Radiation Detector - Version 1
// This version covers the full azimuth.
//
// Check that FRAME is there otherwise we have no place where to put the TRD
AliModule* frame = gAlice->GetModule("FRAME");
if (!frame) return;
// Define the chambers
AliTRD::CreateGeometry();
}
//_____________________________________________________________________________
void AliTRDv1::CreateMaterials()
{
//
// Create materials for the Transition Radiation Detector version 1
//
AliTRD::CreateMaterials();
}
//_____________________________________________________________________________
void AliTRDv1::CreateTRhit(Int_t det)
{
//
// Creates an electron cluster from a TR photon.
// The photon is assumed to be created a the end of the radiator. The
// distance after which it deposits its energy takes into account the
// absorbtion of the entrance window and of the gas mixture in drift
// volume.
//
// PDG code electron
const Int_t kPdgElectron = 11;
// Ionization energy
const Float_t kWion = 22.04;
// Maximum number of TR photons per track
const Int_t kNTR = 50;
TLorentzVector mom, pos;
// Create TR at the entrance of the chamber
if (gMC->IsTrackEntering()) {
// Create TR only for electrons
Int_t iPdg = gMC->TrackPid();
if (TMath::Abs(iPdg) != kPdgElectron) return;
Float_t eTR[kNTR];
Int_t nTR;
// Create TR photons
gMC->TrackMomentum(mom);
Float_t pTot = mom.Rho();
fTR->CreatePhotons(iPdg,pTot,nTR,eTR);
if (nTR > kNTR) {
AliFatal(Form("Boundary error: nTR = %d, kNTR = %d",nTR,kNTR));
}
// Loop through the TR photons
for (Int_t iTR = 0; iTR < nTR; iTR++) {
Float_t energyMeV = eTR[iTR] * 0.001;
Float_t energyeV = eTR[iTR] * 1000.0;
Float_t absLength = 0;
Float_t sigma = 0;
// Take the absorbtion in the entrance window into account
Double_t muMy = fTR->GetMuMy(energyMeV);
sigma = muMy * fFoilDensity;
if (sigma > 0.0) {
absLength = gRandom->Exp(1.0/sigma);
if (absLength < AliTRDgeometry::MyThick()) continue;
}
else {
continue;
}
// The absorbtion cross sections in the drift gas
// Gas-mixture (Xe/CO2)
Double_t muXe = fTR->GetMuXe(energyMeV);
Double_t muCO = fTR->GetMuCO(energyMeV);
sigma = (0.85 * muXe + 0.15 * muCO) * fGasDensity * fTR->GetTemp();
// The distance after which the energy of the TR photon
// is deposited.
if (sigma > 0.0) {
absLength = gRandom->Exp(1.0/sigma);
if (absLength > (AliTRDgeometry::DrThick()
+ AliTRDgeometry::AmThick())) {
continue;
}
}
else {
continue;
}
// The position of the absorbtion
Float_t posHit[3];
gMC->TrackPosition(pos);
posHit[0] = pos[0] + mom[0] / pTot * absLength;
posHit[1] = pos[1] + mom[1] / pTot * absLength;
posHit[2] = pos[2] + mom[2] / pTot * absLength;
// Create the charge
Int_t q = ((Int_t) (energyeV / kWion));
// Add the hit to the array. TR photon hits are marked
// by negative charge
AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber(),det,posHit,-q,kTRUE);
}
}
}
//_____________________________________________________________________________
void AliTRDv1::Init()
{
//
// Initialise Transition Radiation Detector after geometry has been built.
//
AliTRD::Init();
AliDebug(1,"Slow simulator\n");
if (fSensSelect) {
if (fSensPlane >= 0)
AliInfo(Form("Only plane %d is sensitive"));
if (fSensChamber >= 0)
AliInfo(Form("Only chamber %d is sensitive",fSensChamber));
if (fSensSector >= 0) {
Int_t sens1 = fSensSector;
Int_t sens2 = fSensSector + fSensSectorRange;
sens2 -= ((Int_t) (sens2 / AliTRDgeometry::Nsect()))
* AliTRDgeometry::Nsect();
AliInfo(Form("Only sectors %d - %d are sensitive\n",sens1,sens2-1));
}
}
if (fTR)
AliInfo("TR simulation on")
else
AliInfo("TR simulation off");
// First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2)
const Float_t kPoti = 12.1;
// Maximum energy (50 keV);
const Float_t kEend = 50000.0;
// Ermilova distribution for the delta-ray spectrum
Float_t poti = TMath::Log(kPoti);
Float_t eEnd = TMath::Log(kEend);
// Ermilova distribution for the delta-ray spectrum
fDeltaE = new TF1("deltae" ,Ermilova ,poti,eEnd,0);
// Geant3 distribution for the delta-ray spectrum
fDeltaG = new TF1("deltaeg",IntSpecGeant,poti,eEnd,0);
AliDebug(1,"+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++");
}
//_____________________________________________________________________________
AliTRDsim *AliTRDv1::CreateTR()
{
//
// Enables the simulation of TR
//
fTR = new AliTRDsim();
return fTR;
}
//_____________________________________________________________________________
void AliTRDv1::SetSensPlane(Int_t iplane)
{
//
// Defines the hit-sensitive plane (0-5)
//
if ((iplane < 0) || (iplane > 5)) {
AliWarning(Form("Wrong input value:%d",iplane));
AliWarning("Use standard setting");
fSensPlane = -1;
fSensSelect = 0;
return;
}
fSensSelect = 1;
fSensPlane = iplane;
}
//_____________________________________________________________________________
void AliTRDv1::SetSensChamber(Int_t ichamber)
{
//
// Defines the hit-sensitive chamber (0-4)
//
if ((ichamber < 0) || (ichamber > 4)) {
AliWarning(Form("Wrong input value: %d",ichamber));
AliWarning("Use standard setting");
fSensChamber = -1;
fSensSelect = 0;
return;
}
fSensSelect = 1;
fSensChamber = ichamber;
}
//_____________________________________________________________________________
void AliTRDv1::SetSensSector(Int_t isector)
{
//
// Defines the hit-sensitive sector (0-17)
//
SetSensSector(isector,1);
}
//_____________________________________________________________________________
void AliTRDv1::SetSensSector(Int_t isector, Int_t nsector)
{
//
// Defines a range of hit-sensitive sectors. The range is defined by
// (0-17) as the starting point and as the number
// of sectors to be included.
//
if ((isector < 0) || (isector > 17)) {
AliWarning(Form("Wrong input value : %d",isector));
AliWarning("Use standard setting");
fSensSector = -1;
fSensSectorRange = 0;
fSensSelect = 0;
return;
}
if ((nsector < 1) || (nsector > 18)) {
AliWarning(Form("Wrong input value : %d",nsector));
AliWarning("Use standard setting");
fSensSector = -1;
fSensSectorRange = 0;
fSensSelect = 0;
return;
}
fSensSelect = 1;
fSensSector = isector;
fSensSectorRange = nsector;
}
//_____________________________________________________________________________
void AliTRDv1::StepManager()
{
//
// Slow simulator. Every charged track produces electron cluster as hits
// along its path across the drift volume.
//
switch (fTypeOfStepManager) {
case 0 : StepManagerErmilova(); break; // 0 is Ermilova
case 1 : StepManagerGeant(); break; // 1 is Geant
case 2 : StepManagerFixedStep(); break; // 2 is fixed step
default : AliWarning("Not a valid Step Manager.");
}
}
//_____________________________________________________________________________
void AliTRDv1::SelectStepManager(Int_t t)
{
//
// Selects a step manager type:
// 0 - Ermilova
// 1 - Geant3
// 2 - Fixed step size
//
if (t == 1) {
AliWarning("Sorry, Geant parametrization step manager is not implemented yet. Please ask K.Oyama for detail.");
}
fTypeOfStepManager = t;
AliInfo(Form("Step Manager type %d was selected",fTypeOfStepManager));
}
//_____________________________________________________________________________
void AliTRDv1::StepManagerGeant()
{
//
// Slow simulator. Every charged track produces electron cluster as hits
// along its path across the drift volume. The step size is set acording
// to Bethe-Bloch. The energy distribution of the delta electrons follows
// a spectrum taken from Geant3.
//
AliWarning("Not implemented yet.");
}
//_____________________________________________________________________________
void AliTRDv1::StepManagerErmilova()
{
//
// Slow simulator. Every charged track produces electron cluster as hits
// along its path across the drift volume. The step size is set acording
// to Bethe-Bloch. The energy distribution of the delta electrons follows
// a spectrum taken from Ermilova et al.
//
Int_t pla = 0;
Int_t cha = 0;
Int_t sec = 0;
Int_t det = 0;
Int_t iPdg;
Int_t qTot;
Float_t hits[3];
Double_t random[1];
Float_t charge;
Float_t aMass;
Double_t pTot = 0;
Double_t eDelta;
Double_t betaGamma, pp;
Double_t stepSize;
Bool_t drRegion = kFALSE;
Bool_t amRegion = kFALSE;
TString cIdCurrent;
TString cIdSensDr = "J";
TString cIdSensAm = "K";
Char_t cIdChamber[3];
cIdChamber[2] = 0;
TLorentzVector pos, mom;
const Int_t kNplan = AliTRDgeometry::Nplan();
const Int_t kNcham = AliTRDgeometry::Ncham();
const Int_t kNdetsec = kNplan * kNcham;
const Double_t kBig = 1.0E+12; // Infinitely big
const Float_t kWion = 22.04; // Ionization energy
const Float_t kPTotMaxEl = 0.002; // Maximum momentum for e+ e- g
// Minimum energy for the step size adjustment
const Float_t kEkinMinStep = 1.0e-5;
// Plateau value of the energy-loss for electron in xenon
// taken from: Allison + Comb, Ann. Rev. Nucl. Sci. (1980), 30, 253
//const Double_t kPlateau = 1.70;
// the averaged value (26/3/99)
const Float_t kPlateau = 1.55;
const Float_t kPrim = 48.0; // dN1/dx|min for the gas mixture (90% Xe + 10% CO2)
// First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2)
const Float_t kPoti = 12.1;
const Int_t kPdgElectron = 11; // PDG code electron
// Set the maximum step size to a very large number for all
// neutral particles and those outside the driftvolume
gMC->SetMaxStep(kBig);
// Use only charged tracks
if (( gMC->TrackCharge() ) &&
(!gMC->IsTrackStop() ) &&
(!gMC->IsTrackDisappeared())) {
// Inside a sensitive volume?
drRegion = kFALSE;
amRegion = kFALSE;
cIdCurrent = gMC->CurrentVolName();
if (cIdSensDr == cIdCurrent[1]) {
drRegion = kTRUE;
}
if (cIdSensAm == cIdCurrent[1]) {
amRegion = kTRUE;
}
if (drRegion || amRegion) {
// The hit coordinates and charge
gMC->TrackPosition(pos);
hits[0] = pos[0];
hits[1] = pos[1];
hits[2] = pos[2];
// The sector number (0 - 17)
// The numbering goes clockwise and starts at y = 0
Float_t phi = kRaddeg*TMath::ATan2(pos[0],pos[1]);
if (phi < 90.)
phi = phi + 270.;
else
phi = phi - 90.;
sec = ((Int_t) (phi / 20));
// The plane and chamber number
cIdChamber[0] = cIdCurrent[2];
cIdChamber[1] = cIdCurrent[3];
Int_t idChamber = (atoi(cIdChamber) % kNdetsec);
cha = kNcham - ((Int_t) idChamber / kNplan) - 1;
pla = ((Int_t) idChamber % kNplan);
// Check on selected volumes
Int_t addthishit = 1;
if (fSensSelect) {
if ((fSensPlane >= 0) && (pla != fSensPlane )) addthishit = 0;
if ((fSensChamber >= 0) && (cha != fSensChamber)) addthishit = 0;
if (fSensSector >= 0) {
Int_t sens1 = fSensSector;
Int_t sens2 = fSensSector + fSensSectorRange;
sens2 -= ((Int_t) (sens2 / AliTRDgeometry::Nsect()))
* AliTRDgeometry::Nsect();
if (sens1 < sens2) {
if ((sec < sens1) || (sec >= sens2)) addthishit = 0;
}
else {
if ((sec < sens1) && (sec >= sens2)) addthishit = 0;
}
}
}
// Add this hit
if (addthishit) {
// The detector number
det = fGeometry->GetDetector(pla,cha,sec);
// Special hits only in the drift region
if (drRegion) {
// Create a track reference at the entrance and
// exit of each chamber that contain the
// momentum components of the particle
if (gMC->IsTrackEntering() || gMC->IsTrackExiting()) {
gMC->TrackMomentum(mom);
AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber());
}
// Create the hits from TR photons
if (fTR) CreateTRhit(det);
}
// Calculate the energy of the delta-electrons
eDelta = TMath::Exp(fDeltaE->GetRandom()) - kPoti;
eDelta = TMath::Max(eDelta,0.0);
// The number of secondary electrons created
qTot = ((Int_t) (eDelta / kWion) + 1);
// Create a new dEdx hit
if (drRegion) {
AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber()
,det,hits,qTot,kTRUE);
}
else {
AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber()
,det,hits,qTot,kFALSE);
}
// Calculate the maximum step size for the next tracking step
// Produce only one hit if Ekin is below cutoff
aMass = gMC->TrackMass();
if ((gMC->Etot() - aMass) > kEkinMinStep) {
// The energy loss according to Bethe Bloch
iPdg = TMath::Abs(gMC->TrackPid());
if ( (iPdg != kPdgElectron) ||
((iPdg == kPdgElectron) && (pTot < kPTotMaxEl))) {
gMC->TrackMomentum(mom);
pTot = mom.Rho();
betaGamma = pTot / aMass;
pp = kPrim * BetheBloch(betaGamma);
// Take charge > 1 into account
charge = gMC->TrackCharge();
if (TMath::Abs(charge) > 1) pp = pp * charge*charge;
}
// Electrons above 20 Mev/c are at the plateau
else {
pp = kPrim * kPlateau;
}
if (pp > 0) {
do
gMC->GetRandom()->RndmArray(1, random);
while ((random[0] == 1.) || (random[0] == 0.));
stepSize = - TMath::Log(random[0]) / pp;
gMC->SetMaxStep(stepSize);
}
}
}
}
}
}
//_____________________________________________________________________________
void AliTRDv1::StepManagerFixedStep()
{
//
// Slow simulator. Every charged track produces electron cluster as hits
// along its path across the drift volume. The step size is fixed in
// this version of the step manager.
//
Int_t pla = 0;
Int_t cha = 0;
Int_t sec = 0;
Int_t det = 0;
Int_t qTot;
Float_t hits[3];
Double_t eDep;
Bool_t drRegion = kFALSE;
Bool_t amRegion = kFALSE;
TString cIdCurrent;
TString cIdSensDr = "J";
TString cIdSensAm = "K";
Char_t cIdChamber[3];
cIdChamber[2] = 0;
TLorentzVector pos, mom;
const Int_t kNplan = AliTRDgeometry::Nplan();
const Int_t kNcham = AliTRDgeometry::Ncham();
const Int_t kNdetsec = kNplan * kNcham;
const Double_t kBig = 1.0E+12;
const Float_t kWion = 22.04; // Ionization energy
const Float_t kEkinMinStep = 1.0e-5; // Minimum energy for the step size adjustment
// Set the maximum step size to a very large number for all
// neutral particles and those outside the driftvolume
gMC->SetMaxStep(kBig);
// If not charged track or already stopped or disappeared, just return.
if ((!gMC->TrackCharge()) ||
gMC->IsTrackStop() ||
gMC->IsTrackDisappeared()) return;
// Inside a sensitive volume?
cIdCurrent = gMC->CurrentVolName();
if (cIdSensDr == cIdCurrent[1]) drRegion = kTRUE;
if (cIdSensAm == cIdCurrent[1]) amRegion = kTRUE;
if ((!drRegion) && (!amRegion)) return;
// The hit coordinates and charge
gMC->TrackPosition(pos);
hits[0] = pos[0];
hits[1] = pos[1];
hits[2] = pos[2];
// The sector number (0 - 17)
// The numbering goes clockwise and starts at y = 0
Float_t phi = kRaddeg*TMath::ATan2(pos[0],pos[1]);
if (phi < 90.) phi += 270.;
else phi -= 90.;
sec = ((Int_t) (phi / 20.));
// The plane and chamber number
cIdChamber[0] = cIdCurrent[2];
cIdChamber[1] = cIdCurrent[3];
Int_t idChamber = (atoi(cIdChamber) % kNdetsec);
cha = kNcham - ((Int_t) idChamber / kNplan) - 1;
pla = ((Int_t) idChamber % kNplan);
// Check on selected volumes
Int_t addthishit = 1;
if(fSensSelect) {
if ((fSensPlane >= 0) && (pla != fSensPlane )) addthishit = 0;
if ((fSensChamber >= 0) && (cha != fSensChamber)) addthishit = 0;
if (fSensSector >= 0) {
Int_t sens1 = fSensSector;
Int_t sens2 = fSensSector + fSensSectorRange;
sens2 -= ((Int_t) (sens2 / AliTRDgeometry::Nsect())) * AliTRDgeometry::Nsect();
if (sens1 < sens2) {
if ((sec < sens1) || (sec >= sens2)) addthishit = 0;
}
else {
if ((sec < sens1) && (sec >= sens2)) addthishit = 0;
}
}
}
if (!addthishit) return;
det = fGeometry->GetDetector(pla,cha,sec); // The detector number
Int_t trkStat = 0; // 0: InFlight 1:Entering 2:Exiting
// Special hits only in the drift region
if (drRegion) {
// Create a track reference at the entrance and exit of each
// chamber that contain the momentum components of the particle
if (gMC->IsTrackEntering()) {
gMC->TrackMomentum(mom);
AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber());
trkStat = 1;
}
if (gMC->IsTrackExiting()) {
gMC->TrackMomentum(mom);
AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber());
trkStat = 2;
}
// Create the hits from TR photons
if (fTR) CreateTRhit(det);
}
// Calculate the charge according to GEANT Edep
// Create a new dEdx hit
eDep = TMath::Max(gMC->Edep(),0.0) * 1.0e+09;
qTot = (Int_t) (eDep / kWion);
AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber(),det,hits,qTot,drRegion);
// Set Maximum Step Size
// Produce only one hit if Ekin is below cutoff
if ((gMC->Etot() - gMC->TrackMass()) < kEkinMinStep) return;
gMC->SetMaxStep(fStepSize);
}
//_____________________________________________________________________________
Double_t AliTRDv1::BetheBloch(Double_t bg)
{
//
// Parametrization of the Bethe-Bloch-curve
// The parametrization is the same as for the TPC and is taken from Lehrhaus.
//
// This parameters have been adjusted to averaged values from GEANT
const Double_t kP1 = 7.17960e-02;
const Double_t kP2 = 8.54196;
const Double_t kP3 = 1.38065e-06;
const Double_t kP4 = 5.30972;
const Double_t kP5 = 2.83798;
// This parameters have been adjusted to Xe-data found in:
// Allison & Cobb, Ann. Rev. Nucl. Sci. (1980), 30, 253
//const Double_t kP1 = 0.76176E-1;
//const Double_t kP2 = 10.632;
//const Double_t kP3 = 3.17983E-6;
//const Double_t kP4 = 1.8631;
//const Double_t kP5 = 1.9479;
// Lower cutoff of the Bethe-Bloch-curve to limit step sizes
const Double_t kBgMin = 0.8;
const Double_t kBBMax = 6.83298;
//const Double_t kBgMin = 0.6;
//const Double_t kBBMax = 17.2809;
//const Double_t kBgMin = 0.4;
//const Double_t kBBMax = 82.0;
if (bg > kBgMin) {
Double_t yy = bg / TMath::Sqrt(1. + bg*bg);
Double_t aa = TMath::Power(yy,kP4);
Double_t bb = TMath::Power((1./bg),kP5);
bb = TMath::Log(kP3 + bb);
return ((kP2 - aa - bb)*kP1 / aa);
}
else {
return kBBMax;
}
}
//_____________________________________________________________________________
Double_t BetheBlochGeant(Double_t bg)
{
//
// Return dN/dx (number of primary collisions per centimeter)
// for given beta*gamma factor.
//
// Implemented by K.Oyama according to GEANT 3 parametrization shown in
// A.Andronic's webpage: http://www-alice.gsi.de/trd/papers/dedx/dedx.html
// This must be used as a set with IntSpecGeant.
//
Double_t arr_g[20] = {
1.100000, 1.200000, 1.300000, 1.500000,
1.800000, 2.000000, 2.500000, 3.000000,
4.000000, 7.000000, 10.000000, 20.000000,
40.000000, 70.000000, 100.000000, 300.000000,
600.000000, 1000.000000, 3000.000000, 10000.000000 };
Double_t arr_nc[20] = {
75.009056, 45.508083, 35.299252, 27.116327,
22.734999, 21.411915, 19.934095, 19.449375,
19.344431, 20.185553, 21.027925, 22.912676,
24.933352, 26.504053, 27.387468, 29.566597,
30.353779, 30.787134, 31.129285, 31.157350 };
// betagamma to gamma
Double_t g = TMath::Sqrt( 1. + bg*bg );
// Find the index just before the point we need.
int i;
for( i = 0 ; i < 18 ; i++ )
if( arr_g[i] < g && arr_g[i+1] > g )
break;
// Simple interpolation.
Double_t pp = ((arr_nc[i+1] - arr_nc[i]) /
(arr_g[i+1]-arr_g[i])) * (g-arr_g[i]) + arr_nc[i];
return pp;
}
//_____________________________________________________________________________
Double_t Ermilova(Double_t *x, Double_t *)
{
//
// Calculates the delta-ray energy distribution according to Ermilova.
// Logarithmic scale !
//
Double_t energy;
Double_t dpos;
Double_t dnde;
Int_t pos1, pos2;
const Int_t kNv = 31;
Float_t vxe[kNv] = { 2.3026, 2.9957, 3.4012, 3.6889, 3.9120
, 4.0943, 4.2485, 4.3820, 4.4998, 4.6052
, 4.7005, 5.0752, 5.2983, 5.7038, 5.9915
, 6.2146, 6.5221, 6.9078, 7.3132, 7.6009
, 8.0064, 8.5172, 8.6995, 8.9872, 9.2103
, 9.4727, 9.9035,10.3735,10.5966,10.8198
,11.5129 };
Float_t vye[kNv] = { 80.0 , 31.0 , 23.3 , 21.1 , 21.0
, 20.9 , 20.8 , 20.0 , 16.0 , 11.0
, 8.0 , 6.0 , 5.2 , 4.6 , 4.0
, 3.5 , 3.0 , 1.4 , 0.67 , 0.44
, 0.3 , 0.18 , 0.12 , 0.08 , 0.056
, 0.04 , 0.023, 0.015, 0.011, 0.01
, 0.004 };
energy = x[0];
// Find the position
pos1 = pos2 = 0;
dpos = 0;
do {
dpos = energy - vxe[pos2++];
}
while (dpos > 0);
pos2--;
if (pos2 > kNv) pos2 = kNv - 1;
pos1 = pos2 - 1;
// Differentiate between the sampling points
dnde = (vye[pos1] - vye[pos2]) / (vxe[pos2] - vxe[pos1]);
return dnde;
}
//_____________________________________________________________________________
Double_t IntSpecGeant(Double_t *x, Double_t *)
{
//
// Integrated spectrum from Geant3
//
const Int_t n_pts = 83;
Double_t arr_e[n_pts] = {
2.421257, 2.483278, 2.534301, 2.592230,
2.672067, 2.813299, 3.015059, 3.216819,
3.418579, 3.620338, 3.868209, 3.920198,
3.978284, 4.063923, 4.186264, 4.308605,
4.430946, 4.553288, 4.724261, 4.837736,
4.999842, 5.161949, 5.324056, 5.486163,
5.679688, 5.752998, 5.857728, 5.962457,
6.067185, 6.171914, 6.315653, 6.393674,
6.471694, 6.539689, 6.597658, 6.655627,
6.710957, 6.763648, 6.816338, 6.876198,
6.943227, 7.010257, 7.106285, 7.252151,
7.460531, 7.668911, 7.877290, 8.085670,
8.302979, 8.353585, 8.413120, 8.483500,
8.541030, 8.592857, 8.668865, 8.820485,
9.037086, 9.253686, 9.470286, 9.686887,
9.930838, 9.994655, 10.085822, 10.176990,
10.268158, 10.359325, 10.503614, 10.627565,
10.804637, 10.981709, 11.158781, 11.335854,
11.593397, 11.781165, 12.049404, 12.317644,
12.585884, 12.854123, 14.278421, 16.975889,
20.829416, 24.682943, 28.536469
};
Double_t arr_dndx[n_pts] = {
19.344431, 18.664679, 18.136106, 17.567745,
16.836426, 15.677382, 14.281277, 13.140237,
12.207677, 11.445510, 10.697049, 10.562296,
10.414673, 10.182341, 9.775256, 9.172330,
8.240271, 6.898587, 4.808303, 3.889751,
3.345288, 3.093431, 2.897347, 2.692470,
2.436222, 2.340029, 2.208579, 2.086489,
1.975535, 1.876519, 1.759626, 1.705024,
1.656374, 1.502638, 1.330566, 1.200697,
1.101168, 1.019323, 0.943867, 0.851951,
0.755229, 0.671576, 0.570675, 0.449672,
0.326722, 0.244225, 0.188225, 0.149608,
0.121529, 0.116289, 0.110636, 0.103490,
0.096147, 0.089191, 0.079780, 0.063927,
0.047642, 0.036341, 0.028250, 0.022285,
0.017291, 0.016211, 0.014802, 0.013533,
0.012388, 0.011352, 0.009803, 0.008537,
0.007039, 0.005829, 0.004843, 0.004034,
0.003101, 0.002564, 0.001956, 0.001494,
0.001142, 0.000873, 0.000210, 0.000014,
0.000000, 0.000000, 0.000000
};
Int_t i;
Double_t energy = x[0];
Double_t dnde;
for( i = 0 ; i < n_pts ; i++ )
if( energy < arr_e[i] ) break;
if( i == 0 )
AliErrorGeneral("AliTRDv1","Given energy value is too small or zero");
// Interpolate
dnde = (arr_dndx[i-1] - arr_dndx[i]) / (arr_e[i] - arr_e[i-1]);
return dnde;
}