[u/mrichter/AliRoot.git] / ITS / AliITSsimulationSSD.cxx

#include <stdio.h>
#include <stdlib.h>
#include <iostream.h>
#include <TObjArray.h>
#include <TRandom.h>
#include <TMath.h>

#include "AliITSmodule.h"
#include "AliITSMapA2.h"   
#include "AliITSsegmentationSSD.h"
#include "AliITSresponseSSD.h"
#include "AliITSsimulationSSD.h"
//#include "AliITSdictSSD.h"
#include "AliITSdcsSSD.h"
#include "AliITS.h"
#include "AliRun.h"
#include "AliITSgeom.h"

ClassImp(AliITSsimulationSSD);
////////////////////////////////////////////////////////////////////////
// Version: 0
// Written by Enrico Fragiacomo
// July 2000
//
// AliITSsimulationSSD is the simulation of SSDs.

//----------------------------------------------------------------------
AliITSsimulationSSD::AliITSsimulationSSD(AliITSsegmentation *seg,
                                         AliITSresponse *resp){
    // Constructor

    fSegmentation = seg;
    fResponse = resp;
    Float_t noise[2] = {0.,0.};
    fResponse->GetNoiseParam(noise[0],noise[1]); // retrieves noise parameters
    fDCS = new AliITSdcsSSD(seg,resp); 

    fNstrips = fSegmentation->Npx();
    fPitch = fSegmentation->Dpx(0);
    fMapA2 = new AliITSMapA2(fSegmentation);
     
    fSteps  = 100;   // still hard-wired - set in SetDetParam and get it via  
                     // fDCS together with the others eventually    
}
//______________________________________________________________________
AliITSsimulationSSD& AliITSsimulationSSD::operator=(AliITSsimulationSSD 
                                                                      &source){
    // Operator =

    if(this==&source) return *this;

    this->fDCS     = new AliITSdcsSSD(*(source.fDCS));
    this->fMapA2   = source.fMapA2;
    this->fNstrips = source.fNstrips;
    this->fPitch   = source.fPitch;
    this->fSteps   = source.fSteps;
    return *this;
}
//_____________________________________________________________---------
AliITSsimulationSSD::AliITSsimulationSSD(AliITSsimulationSSD &source){
    // copy constructor

    *this = source;
}
//______________________________________________________________________
AliITSsimulationSSD::~AliITSsimulationSSD() {
    // destructor
    delete fMapA2;
    delete fDCS;
}
//_______________________________________________________________-------
void AliITSsimulationSSD::DigitiseModule(AliITSmodule *mod,Int_t module,
                                         Int_t dummy) {
    // Digitizes hits for one SSD module 

    Int_t lay, lad, detect;
    AliITS *aliITS = (AliITS*)gAlice->GetModule("ITS");
    AliITSgeom *geom = aliITS->GetITSgeom();
    geom->GetModuleId(module,lay, lad, detect);
    if ( lay == 6 )((AliITSsegmentationSSD*)fSegmentation)->SetLayer(6);
    if ( lay == 5 )((AliITSsegmentationSSD*)fSegmentation)->SetLayer(5);

    TObjArray *hits = mod->GetHits();
    Int_t nhits = hits->GetEntriesFast();
    if (!nhits) return;
    //cout<<"!! module, nhits ="<<module<<","<<nhits<<endl; 
  
    Double_t x0=0.0, y0=0.0, z0=0.0;
    Double_t x1=0.0, y1=0.0, z1=0.0;
    Double_t de=0.0;
    Int_t maxNdigits = 2*fNstrips; 
    Float_t  **pList = new Float_t* [maxNdigits]; 
    memset(pList,0,sizeof(Float_t*)*maxNdigits);
    Int_t indexRange[4] = {0,0,0,0};
    static Bool_t first=kTRUE;
    Int_t lasttrack = -2;
    Int_t idtrack = -2;
    
    for(Int_t i=0; i<nhits; i++) {    
	// LineSegmentL returns 0 if the hit is entering
	// If hits is exiting returns positions of entering and exiting hits
	// Returns also energy loss

	if (mod->LineSegmentL(i, x0, x1, y0, y1, z0, z1, de, idtrack)) {
	    HitToDigit(module, x0, y0, z0, x1, y1, z1, de, indexRange, first);
       
	    if (lasttrack != idtrack || i==(nhits-1)) {
		GetList(idtrack,pList,indexRange);
		first=kTRUE;
	    } // end if
	    lasttrack=idtrack;
	} // end if
    }  // end loop over hits
  
    ApplyNoise();
    ApplyCoupling();

    ChargeToSignal(pList);

    fMapA2->ClearMap();
}
//----------------------------------------------------------------------
void AliITSsimulationSSD::HitToDigit(Int_t module, Double_t x0, Double_t y0, 
				     Double_t z0, Double_t x1, Double_t y1, 
				     Double_t z1, Double_t de,
				     Int_t *indexRange, Bool_t first) {
    // Turns hits in SSD module into one or more digits.

    Float_t tang[2] = {0.0,0.0};
    fSegmentation->Angles(tang[0], tang[1]);// stereo<<  -> tan(stereo)~=stereo
    Double_t x, y, z;
    Double_t dex=0.0, dey=0.0, dez=0.0;
    Double_t pairs;
    Double_t ionE = 3.62E-9;   // ionization energy of Si (GeV)
    
    Double_t sigma[2] = {0.,0.};// standard deviation of the diffusion gaussian

    Double_t D[2] = {11.,30.}; // diffusion constant {h,e} (cm**2/sec)
    Double_t tdrift[2] = {0.,0.}; // time of drift
    Double_t vdrift[2] = {0.86E6,2.28E6};  // drift velocity (cm/sec)   
    Double_t w;
    Double_t inf[2], sup[2], par0[2];                 
    // Steps in the module are determined "manually" (i.e. No Geant)
    // NumOfSteps divide path between entering and exiting hits in steps 
    Int_t numOfSteps = NumOfSteps(x1, y1, z1, dex, dey, dez);
  
    // Enery loss is equally distributed among steps
    de = de/numOfSteps;
    pairs = de/ionE;             // e-h pairs generated

    for(Int_t j=0; j<numOfSteps; j++) {     // stepping
	//    cout<<"step number ="<<j<<endl;
	x = x0 + (j+0.5)*dex;
	y = y0 + (j+0.5)*dey;
	//if ( y > (seg->Dy()/2 +10)*1.0E-4 ) {
	if ( y > (fSegmentation->Dy()/2+10)*1.0E-4 ) {
	    // check if particle is within the detector
	    cout<<"AliITSsimulationSSD::HitToDigit: Warning: hit "
		"out of detector y0,y,dey,j ="
		<<y0<<","<<y<<","<<dey<<","<<j<<endl;
	    return;
	} // end if
	z = z0 + (j+0.5)*dez;

	// calculate drift time
	// y is the minimum path
	tdrift[0] = (y+(fSegmentation->Dy()*1.0E-4)/2) / vdrift[0];
	tdrift[1] = ((fSegmentation->Dy()*1.0E-4)/2-y) / vdrift[1];

	for(Int_t k=0; k<2; k++) {   // both sides    remember: 0=Pside 1=Nside

	    tang[k]=TMath::Tan(tang[k]);

	    // w is the coord. perpendicular to the strips
	    if(k==0) {
		//w=(x+(seg->Dx()*1.0E-4)/2)-(z+(seg->Dz()*1.0E-4)/2)*tang[k]; 
		w = (x+(fSegmentation->Dx()*1.0E-4)/2) -
		    (z+(fSegmentation->Dz()*1.0E-4)/2)*tang[k]; 
	    }else{
		//w =(x+(seg->Dx()*1.0E-4)/2)+(z-(seg->Dz()*1.0E-4)/2)*tang[k];
		w = (x+(fSegmentation->Dx()*1.0E-4)/2) + 
		    (z-(fSegmentation->Dz()*1.0E-4)/2)*tang[k]; 
		//cout<<"k,x,z,w ="<<k<<","<<x<<","<<z<<","<<w<<endl;
	    } // end if
	    w = w / (fPitch*1.0E-4); // w is converted in units of pitch

	    if((w<(-0.5)) || (w>(fNstrips-0.5))) {
		// this check rejects hits in regions not covered by strips
		// 0.5 takes into account boundaries 
		if(k==0) cout<<"AliITSsimulationSSD::HitToDigit: "
			     "Warning: no strip in this region of P side"
			     <<endl;
		else cout<<"AliITSsimulationSSD::HitToDigit: "
			 "Warning: no strip in this region of N side"<<endl;
		return;
	    } // end if

	    // sigma is the standard deviation of the diffusion gaussian

	    if(tdrift[k]<0) return;

	    sigma[k] = TMath::Sqrt(2*D[k]*tdrift[k]);
	    sigma[k] = sigma[k] /(fPitch*1.0E-4);  //units of Pitch
	    if(sigma[k]==0.0) { 	
		cout<<"AliITSsimulationSSD::DigitiseModule: Error: sigma=0"
		    <<endl; 
		exit(0);
	    } // end if

	    par0[k] = pairs;
	    // we integrate the diffusion gaussian from -3sigma to 3sigma 
	    inf[k] = w - 3*sigma[k]; // 3 sigma from the gaussian average  
	    sup[k] = w + 3*sigma[k]; // 3 sigma from the gaussian average
	                             // IntegrateGaussian does the actual
                                     // integration of diffusion gaussian
	    IntegrateGaussian(k, par0[k], w, sigma[k], inf[k], sup[k], 
			      indexRange, first);
	}  // end for loop over side (0=Pside, 1=Nside)      
    } // end stepping
    //delete seg;
}
//____________________________________________________________________--
void AliITSsimulationSSD::ApplyNoise() {
    // Apply Noise.
  
    Float_t signal;
    Float_t noise[2] = {0.,0.};
    fResponse->GetNoiseParam(noise[0],noise[1]); // retrieves noise parameters

    for(Int_t k=0;k<2;k++){                    // both sides (0=Pside, 1=Nside)
	for(Int_t ix=0;ix<fNstrips;ix++){            // loop over strips
	    signal = (Float_t) fMapA2->GetSignal(k,ix);// retrieves signal
                                                       // from map

	    signal += gRandom->Gaus(0,noise[k]);// add noise to signal
	    if(signal<0.) signal=0.0;           // in case noise is negative...

	    fMapA2->SetHit(k,ix,(Double_t)signal); // give back signal to map
	} // loop over strip 
    } // loop over k (P or N side)
}
//______________________________________________________________________
void AliITSsimulationSSD::ApplyCoupling() {
    // Apply the effect of electronic coupling between channels
    Float_t signal, signalLeft=0, signalRight=0;

    for(Int_t ix=0;ix<fNstrips;ix++){
	if(ix>0.) signalLeft  = (Float_t) fMapA2->GetSignal(0,ix-1)*
		                                        fDCS->GetCouplingPL();
	else signalLeft = 0.0;
	if(ix<(fNstrips-1)) signalRight = (Float_t) fMapA2->GetSignal(0,ix+1)*
                                                        fDCS->GetCouplingPR();
	else signalRight = 0.0;
	signal = (Float_t) fMapA2->GetSignal(0,ix);
	signal += signalLeft + signalRight;
	fMapA2->SetHit(0,ix,(Double_t)signal);
    
	if(ix>0.) signalLeft  = (Float_t) fMapA2->GetSignal(1,ix-1)*
                                                        fDCS->GetCouplingNL();
	else signalLeft = 0.0;
	if(ix<(fNstrips-1)) signalRight = (Float_t) fMapA2->GetSignal(1,ix+1)*
                                                         fDCS->GetCouplingNR();
	else signalRight = 0.0;
	signal = (Float_t) fMapA2->GetSignal(1,ix);
	signal += signalLeft + signalRight;
	fMapA2->SetHit(1,ix,(Double_t)signal);
    } // loop over strips 
}
//______________________________________________________________________
Float_t AliITSsimulationSSD::F(Float_t av, Float_t x, Float_t s) {
    // Computes the integral of a gaussian using Error Function
    Float_t sqrt2 = TMath::Sqrt(2.0);
    Float_t sigm2 = sqrt2*s;
    Float_t integral;

    integral = 0.5 * TMath::Erf( (x - av) / sigm2);
    return integral;
}
//______________________________________________________________________
void AliITSsimulationSSD::IntegrateGaussian(Int_t k,Double_t par, Double_t w,
					    Double_t sigma, 
					    Double_t inf, Double_t sup,
					    Int_t *indexRange, Bool_t first) {
    // integrate the diffusion gaussian
    // remind: inf and sup are w-3sigma and w+3sigma
    //         we could define them here instead of passing them
    //         this way we are free to introduce asimmetry

    Double_t a=0.0, b=0.0;
    Double_t signal = 0.0, dXCharge1 = 0.0, dXCharge2 = 0.0;
    // dXCharge1 and 2 are the charge to two neighbouring strips
    // Watch that we only involve at least two strips
    // Numbers greater than 2 of strips in a cluster depend on
    //  geometry of the track and delta rays, not charge diffusion!   
  
    Double_t strip = TMath::Floor(w);         // clostest strip on the left

    if ( TMath::Abs((strip - w)) < 0.5) { 
	// gaussian mean is closer to strip on the left
	a = inf;                         // integration starting point
	if((strip+0.5)<=sup) {
	    // this means that the tail of the gaussian goes beyond
	    // the middle point between strips ---> part of the signal
	    // is given to the strip on the right
	    b = strip + 0.5;               // integration stopping point
	    dXCharge1 = F( w, b, sigma) - F(w, a, sigma);
	    dXCharge2 = F( w, sup, sigma) - F(w ,b, sigma); 
	}else { 
	    // this means that all the charge is given to the strip on the left
	    b = sup;
	    dXCharge1 = 0.9973;   // gaussian integral at 3 sigmas
	    dXCharge2 = 0.0;
	} // end if

	dXCharge1 = par * dXCharge1;// normalize by mean of number of carriers
	dXCharge2 = par * dXCharge2;

	// for the time being, signal is the charge
	// in ChargeToSignal signal is converted in ADC channel
	signal = fMapA2->GetSignal(k,strip);
	signal += dXCharge1;

	fMapA2->SetHit(k,strip,(Double_t)signal);
	if(((Int_t) strip) < (fNstrips-1)) {
	    // strip doesn't have to be the last (remind: last=fNstrips-1)
	    // otherwise part of the charge is lost
	    signal = fMapA2->GetSignal(k,(strip+1));
	    signal += dXCharge2;
	    fMapA2->SetHit(k,(strip+1),(Double_t)signal);
	} // end if
    
	if(dXCharge1 > 1.) {
	    if (first) {
		indexRange[k*2+0]=indexRange[k*2+1]=(Int_t) strip;
		first=kFALSE;
	    } // end if first

	    indexRange[k*2+0]=TMath::Min(indexRange[k*2+0],(Int_t) strip);
	    indexRange[k*2+1]=TMath::Max(indexRange[k*2+1],(Int_t) strip);
	}      // dXCharge > 1 e-

    }else{
	// gaussian mean is closer to strip on the right
	strip++;     // move to strip on the rigth
	b = sup;     // now you know where to stop integrating
	if((strip-0.5)>=inf) { 
	    // tail of diffusion gaussian on the left goes left of
	    // middle point between strips
	    a = strip - 0.5;        // integration starting point
	    dXCharge1 = F(w, b, sigma) - F(w, a, sigma);
	    dXCharge2 = F(w, a, sigma) - F(w, inf, sigma);
	}else {
	    a = inf;
	    dXCharge1 = 0.9973;   // gaussian integral at 3 sigmas
	    dXCharge2 = 0.0;
	} // end if
    
	dXCharge1 = par * dXCharge1;    // normalize by means of carriers
	dXCharge2 = par * dXCharge2;

	// for the time being, signal is the charge
	// in ChargeToSignal signal is converted in ADC channel
	signal = fMapA2->GetSignal(k,strip);
	signal += dXCharge1;
	fMapA2->SetHit(k,strip,(Double_t)signal);
	if(((Int_t) strip) > 0) {
	    // strip doesn't have to be the first
	    // otherwise part of the charge is lost
	    signal = fMapA2->GetSignal(k,(strip-1));
	    signal += dXCharge2;
	    fMapA2->SetHit(k,(strip-1),(Double_t)signal);
	} // end if
    
	if(dXCharge1 > 1.) {
	    if (first) {
		indexRange[k*2+0]=indexRange[k*2+1]=(Int_t) strip;
		first=kFALSE;
	    } // end if first

	    indexRange[k*2+0]=TMath::Min(indexRange[k*2+0],(Int_t) strip);
	    indexRange[k*2+1]=TMath::Max(indexRange[k*2+1],(Int_t) strip);
	}      // dXCharge > 1 e-
    } // end if
}
//______________________________________________________________________
Int_t AliITSsimulationSSD::NumOfSteps(Double_t x, Double_t y, Double_t z,
				 Double_t & dex,Double_t & dey,Double_t & dez){
    // number of steps
    // it also returns steps for each coord
    //AliITSsegmentationSSD *seg = new AliITSsegmentationSSD();

    Double_t step = 25E-4;
    //step = (Double_t) seg->GetStepSize();  // step size (cm)
    Int_t numOfSteps = (Int_t) (TMath::Sqrt(x*x+y*y+z*z)/step); 

    if (numOfSteps < 1) numOfSteps = 1;       // one step, at least

    // we could condition the stepping depending on the incident angle
    // of the track
    dex = x/numOfSteps;
    dey = y/numOfSteps;
    dez = z/numOfSteps;

    return numOfSteps;
}
//----------------------------------------------------------------------
void AliITSsimulationSSD::GetList(Int_t label,Float_t **pList,
				  Int_t *indexRange) {
    // loop over nonzero digits
    Int_t ix,globalIndex;
    Float_t signal=0.;
    Float_t highest,middle,lowest;
  // printf("SPD-GetList: indexRange[0] indexRange[1] indexRange[2] indexRange[3] %d %d %d %d\n",indexRange[0], indexRange[1], indexRange[2], indexRange[3]);

    for(Int_t k=0; k<2; k++) {
	for(ix=indexRange[k*2+0];ix<indexRange[k*2+1]+1;ix++){
	    if(indexRange[k*2+0]<indexRange[k*2+1]) 
		signal=fMapA2->GetSignal(k,ix);
      
	    globalIndex = k*fNstrips+ix; // globalIndex starts from 0!
	    if(!pList[globalIndex]){
		// 
		//Create new list (6 elements-3 signals and 3 tracks+total sig)
		//
		pList[globalIndex] = new Float_t [6];
		// set list to -1
		*pList[globalIndex] = -2.;
		*(pList[globalIndex]+1) = -2.;
		*(pList[globalIndex]+2) = -2.;
		*(pList[globalIndex]+3) =  0.;
		*(pList[globalIndex]+4) =  0.;
		*(pList[globalIndex]+5) =  0.;
		*pList[globalIndex] = (float)label;
		*(pList[globalIndex]+3) = signal;
	    }else{
		// check the signal magnitude
		highest = *(pList[globalIndex]+3);
		middle = *(pList[globalIndex]+4);
		lowest = *(pList[globalIndex]+5);
		signal -= (highest+middle+lowest);
		//
		//  compare the new signal with already existing list
		//
		if(signal<lowest) continue; // neglect this track
		if (signal>highest){
		    *(pList[globalIndex]+5) = middle;
		    *(pList[globalIndex]+4) = highest;
		    *(pList[globalIndex]+3) = signal;
		    *(pList[globalIndex]+2) = *(pList[globalIndex]+1);
		    *(pList[globalIndex]+1) = *pList[globalIndex];
		    *pList[globalIndex] = label;
		}else if (signal>middle){
		    *(pList[globalIndex]+5) = middle;
		    *(pList[globalIndex]+4) = signal;
		    *(pList[globalIndex]+2) = *(pList[globalIndex]+1);
		    *(pList[globalIndex]+1) = label;
		}else{
		    *(pList[globalIndex]+5) = signal;
		    *(pList[globalIndex]+2) = label;
		} // end if
	    } // end if
	} // end of loop pixels in x
    } // end of loop over pixels in z
}
//----------------------------------------------------------------------
void AliITSsimulationSSD::ChargeToSignal(Float_t **pList) {
    // charge to signal
    AliITS *aliITS = (AliITS*)gAlice->GetModule("ITS");
    Float_t threshold = 0.;
    Int_t digits[3], tracks[3],hits[3],gi,j1;
    Float_t charges[3];
    Float_t signal,phys;
    Float_t noise[2] = {0.,0.};

    fResponse->GetNoiseParam(noise[0],noise[1]);
  
    for(Int_t k=0;k<2;k++){         // both sides (0=Pside, 1=Nside)

	// Threshold for zero-suppression
	// It can be defined in AliITSresponseSSD
	//             threshold = (Float_t)fResponse->MinVal(k);
	// I prefer to think adjusting the threshold "manually", looking
	// at the scope, and considering noise standard deviation
	threshold = 4.0*noise[k];      // 4 times noise is a choice
	for(Int_t ix=0;ix<fNstrips;ix++){         // loop over strips

	    signal = (Float_t) fMapA2->GetSignal(k,ix);

	    gi =k*fNstrips+ix; // global index
	    if (signal > threshold) {
		digits[0]=k;
		digits[1]=ix;

		// convert to ADC signal
		// conversion factor are rather arbitrary (need tuning)
		// minimum ionizing particle--> ~30000 pairs--> ADC channel 50
		signal = signal*50.0/30000.0;        
		if(signal>1000.) signal = 1000.0;//if exceeding, accumulate
                                                 // last one
		digits[2]=(Int_t) signal;

		//gi =k*fNstrips+ix; // global index
		for(j1=0;j1<3;j1++){
		    if (pList[gi]) {
			tracks[j1] = (Int_t)(*(pList[gi]+j1));
		    } else {
			tracks[j1]=-2; //noise
		    } // end if pList
		    charges[j1] = 0;
		} // end for j1

		phys=0;

		hits[0]=0;
		hits[1]=0;
		hits[2]=0;
		// finally add digit
		aliITS->AddSimDigit(2,phys,digits,tracks,hits,charges);

		//if(pList[gi]) delete [] pList[gi];
	    } // end if signal > threshold
	    if(pList[gi]) delete [] pList[gi];
	} // end for ix
    } // end for k
    delete [] pList;
}
Commit	Line	Data
b0f5e3fc	1	#include <stdio.h>
8a00af9a	2	#include <stdlib.h>
fd61217e	3	#include <iostream.h>
b0f5e3fc	4	#include <TObjArray.h>
1ca7869b	5	#include <TRandom.h>
fd61217e	6	#include <TMath.h>
b0f5e3fc	7
fd61217e	8	#include "AliITSmodule.h"
fd61217e	9	#include "AliITSMapA2.h"
9e8d6423	10	#include "AliITSsegmentationSSD.h"
9e8d6423	11	#include "AliITSresponseSSD.h"
b0f5e3fc	12	#include "AliITSsimulationSSD.h"
fd61217e	13	//#include "AliITSdictSSD.h"
b0f5e3fc	14	#include "AliITSdcsSSD.h"
	15	#include "AliITS.h"
	16	#include "AliRun.h"
0315d466	17	#include "AliITSgeom.h"
b0f5e3fc	18
b0f5e3fc	19	ClassImp(AliITSsimulationSSD);
fd61217e	20	////////////////////////////////////////////////////////////////////////
	21	// Version: 0
	22	// Written by Enrico Fragiacomo
	23	// July 2000
	24	//
	25	// AliITSsimulationSSD is the simulation of SSDs.
	26
0315d466	27	//----------------------------------------------------------------------
b0f5e3fc	28	AliITSsimulationSSD::AliITSsimulationSSD(AliITSsegmentation *seg,
b0f5e3fc	29	AliITSresponse *resp){
0315d466	30	// Constructor
b0f5e3fc	31
	32	fSegmentation = seg;
	33	fResponse = resp;
0315d466	34	Float_t noise[2] = {0.,0.};
	35	fResponse->GetNoiseParam(noise[0],noise[1]); // retrieves noise parameters
	36	fDCS = new AliITSdcsSSD(seg,resp);
b0f5e3fc	37
	38	fNstrips = fSegmentation->Npx();
	39	fPitch = fSegmentation->Dpx(0);
fd61217e	40	fMapA2 = new AliITSMapA2(fSegmentation);
fd61217e	41
fd61217e	42	fSteps = 100; // still hard-wired - set in SetDetParam and get it via
b0f5e3fc	43	// fDCS together with the others eventually
b0f5e3fc	44	}
0315d466	45	//______________________________________________________________________
b0f5e3fc	46	AliITSsimulationSSD& AliITSsimulationSSD::operator=(AliITSsimulationSSD
b0f5e3fc	47	&source){
0315d466	48	// Operator =
fd61217e	49
b0f5e3fc	50	if(this==&source) return *this;
b0f5e3fc	51
0315d466	52	this->fDCS = new AliITSdcsSSD(*(source.fDCS));
0315d466	53	this->fMapA2 = source.fMapA2;
b0f5e3fc	54	this->fNstrips = source.fNstrips;
	55	this->fPitch = source.fPitch;
	56	this->fSteps = source.fSteps;
	57	return *this;
	58	}
0315d466	59	//_____________________________________________________________---------
b0f5e3fc	60	AliITSsimulationSSD::AliITSsimulationSSD(AliITSsimulationSSD &source){
0315d466	61	// copy constructor
fd61217e	62
0315d466	63	*this = source;
b0f5e3fc	64	}
0315d466	65	//______________________________________________________________________
b0f5e3fc	66	AliITSsimulationSSD::~AliITSsimulationSSD() {
0315d466	67	// destructor
fd61217e	68	delete fMapA2;
b0f5e3fc	69	delete fDCS;
0315d466	70	}
0315d466	71	//_______________________________________________________________-------
b0f5e3fc	72	void AliITSsimulationSSD::DigitiseModule(AliITSmodule *mod,Int_t module,
b0f5e3fc	73	Int_t dummy) {
0315d466	74	// Digitizes hits for one SSD module
	75
	76	Int_t lay, lad, detect;
	77	AliITS aliITS = (AliITS)gAlice->GetModule("ITS");
	78	AliITSgeom *geom = aliITS->GetITSgeom();
	79	geom->GetModuleId(module,lay, lad, detect);
	80	if ( lay == 6 )((AliITSsegmentationSSD*)fSegmentation)->SetLayer(6);
	81	if ( lay == 5 )((AliITSsegmentationSSD*)fSegmentation)->SetLayer(5);
	82
	83	TObjArray *hits = mod->GetHits();
	84	Int_t nhits = hits->GetEntriesFast();
	85	if (!nhits) return;
	86	//cout<<"!! module, nhits ="<<module<<","<<nhits<<endl;
fd61217e	87
0315d466	88	Double_t x0=0.0, y0=0.0, z0=0.0;
	89	Double_t x1=0.0, y1=0.0, z1=0.0;
	90	Double_t de=0.0;
	91	Int_t maxNdigits = 2*fNstrips;
	92	Float_t *pList = new Float_t [maxNdigits];
	93	memset(pList,0,sizeof(Float_t)maxNdigits);
	94	Int_t indexRange[4] = {0,0,0,0};
	95	static Bool_t first=kTRUE;
	96	Int_t lasttrack = -2;
	97	Int_t idtrack = -2;
b0f5e3fc	98
0315d466	99	for(Int_t i=0; i<nhits; i++) {
	100	// LineSegmentL returns 0 if the hit is entering
	101	// If hits is exiting returns positions of entering and exiting hits
	102	// Returns also energy loss
	103
	104	if (mod->LineSegmentL(i, x0, x1, y0, y1, z0, z1, de, idtrack)) {
	105	HitToDigit(module, x0, y0, z0, x1, y1, z1, de, indexRange, first);
fd61217e	106
0315d466	107	if (lasttrack != idtrack \|\| i==(nhits-1)) {
	108	GetList(idtrack,pList,indexRange);
	109	first=kTRUE;
	110	} // end if
	111	lasttrack=idtrack;
	112	} // end if
	113	} // end loop over hits
fd61217e	114
0315d466	115	ApplyNoise();
0315d466	116	ApplyCoupling();
e8189707	117
0315d466	118	ChargeToSignal(pList);
b0f5e3fc	119
0315d466	120	fMapA2->ClearMap();
b0f5e3fc	121	}
0315d466	122	//----------------------------------------------------------------------
fd61217e	123	void AliITSsimulationSSD::HitToDigit(Int_t module, Double_t x0, Double_t y0,
	124	Double_t z0, Double_t x1, Double_t y1,
	125	Double_t z1, Double_t de,
	126	Int_t *indexRange, Bool_t first) {
0315d466	127	// Turns hits in SSD module into one or more digits.
	128
	129	Float_t tang[2] = {0.0,0.0};
	130	fSegmentation->Angles(tang[0], tang[1]);// stereo<< -> tan(stereo)~=stereo
	131	Double_t x, y, z;
	132	Double_t dex=0.0, dey=0.0, dez=0.0;
	133	Double_t pairs;
	134	Double_t ionE = 3.62E-9; // ionization energy of Si (GeV)
b0f5e3fc	135
0315d466	136	Double_t sigma[2] = {0.,0.};// standard deviation of the diffusion gaussian
	137
	138	Double_t D[2] = {11.,30.}; // diffusion constant {h,e} (cm**2/sec)
	139	Double_t tdrift[2] = {0.,0.}; // time of drift
	140	Double_t vdrift[2] = {0.86E6,2.28E6}; // drift velocity (cm/sec)
	141	Double_t w;
	142	Double_t inf[2], sup[2], par0[2];
	143	// Steps in the module are determined "manually" (i.e. No Geant)
	144	// NumOfSteps divide path between entering and exiting hits in steps
	145	Int_t numOfSteps = NumOfSteps(x1, y1, z1, dex, dey, dez);
fd61217e	146
0315d466	147	// Enery loss is equally distributed among steps
	148	de = de/numOfSteps;
	149	pairs = de/ionE; // e-h pairs generated
	150
	151	for(Int_t j=0; j<numOfSteps; j++) { // stepping
	152	// cout<<"step number ="<<j<<endl;
	153	x = x0 + (j+0.5)*dex;
	154	y = y0 + (j+0.5)*dey;
	155	//if ( y > (seg->Dy()/2 +10)*1.0E-4 ) {
	156	if ( y > (fSegmentation->Dy()/2+10)*1.0E-4 ) {
	157	// check if particle is within the detector
	158	cout<<"AliITSsimulationSSD::HitToDigit: Warning: hit "
	159	"out of detector y0,y,dey,j ="
	160	<<y0<<","<<y<<","<<dey<<","<<j<<endl;
	161	return;
	162	} // end if
	163	z = z0 + (j+0.5)*dez;
	164
	165	// calculate drift time
	166	// y is the minimum path
	167	tdrift[0] = (y+(fSegmentation->Dy()*1.0E-4)/2) / vdrift[0];
	168	tdrift[1] = ((fSegmentation->Dy()*1.0E-4)/2-y) / vdrift[1];
	169
	170	for(Int_t k=0; k<2; k++) { // both sides remember: 0=Pside 1=Nside
	171
	172	tang[k]=TMath::Tan(tang[k]);
	173
	174	// w is the coord. perpendicular to the strips
	175	if(k==0) {
	176	//w=(x+(seg->Dx()1.0E-4)/2)-(z+(seg->Dz()1.0E-4)/2)*tang[k];
	177	w = (x+(fSegmentation->Dx()*1.0E-4)/2) -
	178	(z+(fSegmentation->Dz()1.0E-4)/2)tang[k];
	179	}else{
	180	//w =(x+(seg->Dx()1.0E-4)/2)+(z-(seg->Dz()1.0E-4)/2)*tang[k];
	181	w = (x+(fSegmentation->Dx()*1.0E-4)/2) +
	182	(z-(fSegmentation->Dz()1.0E-4)/2)tang[k];
	183	//cout<<"k,x,z,w ="<<k<<","<<x<<","<<z<<","<<w<<endl;
	184	} // end if
	185	w = w / (fPitch*1.0E-4); // w is converted in units of pitch
	186
	187	if((w<(-0.5)) \|\| (w>(fNstrips-0.5))) {
	188	// this check rejects hits in regions not covered by strips
	189	// 0.5 takes into account boundaries
	190	if(k==0) cout<<"AliITSsimulationSSD::HitToDigit: "
	191	"Warning: no strip in this region of P side"
	192	<<endl;
	193	else cout<<"AliITSsimulationSSD::HitToDigit: "
	194	"Warning: no strip in this region of N side"<<endl;
	195	return;
	196	} // end if
	197
	198	// sigma is the standard deviation of the diffusion gaussian
	199
	200	if(tdrift[k]<0) return;
	201
	202	sigma[k] = TMath::Sqrt(2D[k]tdrift[k]);
	203	sigma[k] = sigma[k] /(fPitch*1.0E-4); //units of Pitch
	204	if(sigma[k]==0.0) {
	205	cout<<"AliITSsimulationSSD::DigitiseModule: Error: sigma=0"
	206	<<endl;
	207	exit(0);
	208	} // end if
	209
	210	par0[k] = pairs;
211	// we integrate the diffusion gaussian from -3sigma to 3sigma
212	inf[k] = w - 3*sigma[k]; // 3 sigma from the gaussian average
213	sup[k] = w + 3*sigma[k]; // 3 sigma from the gaussian average
214	// IntegrateGaussian does the actual
215	// integration of diffusion gaussian
216	IntegrateGaussian(k, par0[k], w, sigma[k], inf[k], sup[k],
217	indexRange, first);
218	} // end for loop over side (0=Pside, 1=Nside)
219	} // end stepping
220	//delete seg;
b0f5e3fc	221	}
0315d466	222	//____________________________________________________________________--
b0f5e3fc	223	void AliITSsimulationSSD::ApplyNoise() {
0315d466	224	// Apply Noise.
fd61217e	225
0315d466	226	Float_t signal;
	227	Float_t noise[2] = {0.,0.};
	228	fResponse->GetNoiseParam(noise[0],noise[1]); // retrieves noise parameters
fd61217e	229
0315d466	230	for(Int_t k=0;k<2;k++){ // both sides (0=Pside, 1=Nside)
	231	for(Int_t ix=0;ix<fNstrips;ix++){ // loop over strips
	232	signal = (Float_t) fMapA2->GetSignal(k,ix);// retrieves signal
	233	// from map
fd61217e	234
0315d466	235	signal += gRandom->Gaus(0,noise[k]);// add noise to signal
0315d466	236	if(signal<0.) signal=0.0; // in case noise is negative...
fd61217e	237
0315d466	238	fMapA2->SetHit(k,ix,(Double_t)signal); // give back signal to map
	239	} // loop over strip
	240	} // loop over k (P or N side)
b0f5e3fc	241	}
0315d466	242	//______________________________________________________________________
b0f5e3fc	243	void AliITSsimulationSSD::ApplyCoupling() {
0315d466	244	// Apply the effect of electronic coupling between channels
	245	Float_t signal, signalLeft=0, signalRight=0;
	246
	247	for(Int_t ix=0;ix<fNstrips;ix++){
	248	if(ix>0.) signalLeft = (Float_t) fMapA2->GetSignal(0,ix-1)*
	249	fDCS->GetCouplingPL();
	250	else signalLeft = 0.0;
	251	if(ix<(fNstrips-1)) signalRight = (Float_t) fMapA2->GetSignal(0,ix+1)*
	252	fDCS->GetCouplingPR();
	253	else signalRight = 0.0;
	254	signal = (Float_t) fMapA2->GetSignal(0,ix);
	255	signal += signalLeft + signalRight;
	256	fMapA2->SetHit(0,ix,(Double_t)signal);
fd61217e	257
0315d466	258	if(ix>0.) signalLeft = (Float_t) fMapA2->GetSignal(1,ix-1)*
	259	fDCS->GetCouplingNL();
	260	else signalLeft = 0.0;
	261	if(ix<(fNstrips-1)) signalRight = (Float_t) fMapA2->GetSignal(1,ix+1)*
	262	fDCS->GetCouplingNR();
	263	else signalRight = 0.0;
	264	signal = (Float_t) fMapA2->GetSignal(1,ix);
	265	signal += signalLeft + signalRight;
	266	fMapA2->SetHit(1,ix,(Double_t)signal);
	267	} // loop over strips
b0f5e3fc	268	}
0315d466	269	//______________________________________________________________________
fd61217e	270	Float_t AliITSsimulationSSD::F(Float_t av, Float_t x, Float_t s) {
0315d466	271	// Computes the integral of a gaussian using Error Function
	272	Float_t sqrt2 = TMath::Sqrt(2.0);
	273	Float_t sigm2 = sqrt2*s;
	274	Float_t integral;
fd61217e	275
0315d466	276	integral = 0.5 * TMath::Erf( (x - av) / sigm2);
	277	return integral;
	278	}
	279	//______________________________________________________________________
fd61217e	280	void AliITSsimulationSSD::IntegrateGaussian(Int_t k,Double_t par, Double_t w,
	281	Double_t sigma,
	282	Double_t inf, Double_t sup,
	283	Int_t *indexRange, Bool_t first) {
0315d466	284	// integrate the diffusion gaussian
	285	// remind: inf and sup are w-3sigma and w+3sigma
	286	// we could define them here instead of passing them
	287	// this way we are free to introduce asimmetry
	288
	289	Double_t a=0.0, b=0.0;
	290	Double_t signal = 0.0, dXCharge1 = 0.0, dXCharge2 = 0.0;
	291	// dXCharge1 and 2 are the charge to two neighbouring strips
	292	// Watch that we only involve at least two strips
	293	// Numbers greater than 2 of strips in a cluster depend on
	294	// geometry of the track and delta rays, not charge diffusion!
fd61217e	295
0315d466	296	Double_t strip = TMath::Floor(w); // clostest strip on the left
	297
	298	if ( TMath::Abs((strip - w)) < 0.5) {
	299	// gaussian mean is closer to strip on the left
	300	a = inf; // integration starting point
	301	if((strip+0.5)<=sup) {
	302	// this means that the tail of the gaussian goes beyond
	303	// the middle point between strips ---> part of the signal
	304	// is given to the strip on the right
	305	b = strip + 0.5; // integration stopping point
	306	dXCharge1 = F( w, b, sigma) - F(w, a, sigma);
	307	dXCharge2 = F( w, sup, sigma) - F(w ,b, sigma);
	308	}else {
	309	// this means that all the charge is given to the strip on the left
	310	b = sup;
	311	dXCharge1 = 0.9973; // gaussian integral at 3 sigmas
	312	dXCharge2 = 0.0;
	313	} // end if
	314
	315	dXCharge1 = par * dXCharge1;// normalize by mean of number of carriers
	316	dXCharge2 = par * dXCharge2;
	317
	318	// for the time being, signal is the charge
	319	// in ChargeToSignal signal is converted in ADC channel
	320	signal = fMapA2->GetSignal(k,strip);
	321	signal += dXCharge1;
	322
	323	fMapA2->SetHit(k,strip,(Double_t)signal);
	324	if(((Int_t) strip) < (fNstrips-1)) {
	325	// strip doesn't have to be the last (remind: last=fNstrips-1)
	326	// otherwise part of the charge is lost
	327	signal = fMapA2->GetSignal(k,(strip+1));
	328	signal += dXCharge2;
	329	fMapA2->SetHit(k,(strip+1),(Double_t)signal);
	330	} // end if
fd61217e	331
0315d466	332	if(dXCharge1 > 1.) {
	333	if (first) {
	334	indexRange[k2+0]=indexRange[k2+1]=(Int_t) strip;
	335	first=kFALSE;
	336	} // end if first
	337
	338	indexRange[k2+0]=TMath::Min(indexRange[k2+0],(Int_t) strip);
	339	indexRange[k2+1]=TMath::Max(indexRange[k2+1],(Int_t) strip);
	340	} // dXCharge > 1 e-
	341
	342	}else{
	343	// gaussian mean is closer to strip on the right
	344	strip++; // move to strip on the rigth
	345	b = sup; // now you know where to stop integrating
	346	if((strip-0.5)>=inf) {
	347	// tail of diffusion gaussian on the left goes left of
	348	// middle point between strips
	349	a = strip - 0.5; // integration starting point
	350	dXCharge1 = F(w, b, sigma) - F(w, a, sigma);
	351	dXCharge2 = F(w, a, sigma) - F(w, inf, sigma);
	352	}else {
	353	a = inf;
	354	dXCharge1 = 0.9973; // gaussian integral at 3 sigmas
	355	dXCharge2 = 0.0;
	356	} // end if
fd61217e	357
0315d466	358	dXCharge1 = par * dXCharge1; // normalize by means of carriers
	359	dXCharge2 = par * dXCharge2;
	360
	361	// for the time being, signal is the charge
	362	// in ChargeToSignal signal is converted in ADC channel
	363	signal = fMapA2->GetSignal(k,strip);
	364	signal += dXCharge1;
	365	fMapA2->SetHit(k,strip,(Double_t)signal);
	366	if(((Int_t) strip) > 0) {
	367	// strip doesn't have to be the first
	368	// otherwise part of the charge is lost
	369	signal = fMapA2->GetSignal(k,(strip-1));
	370	signal += dXCharge2;
	371	fMapA2->SetHit(k,(strip-1),(Double_t)signal);
	372	} // end if
fd61217e	373
0315d466	374	if(dXCharge1 > 1.) {
	375	if (first) {
	376	indexRange[k2+0]=indexRange[k2+1]=(Int_t) strip;
	377	first=kFALSE;
	378	} // end if first
	379
	380	indexRange[k2+0]=TMath::Min(indexRange[k2+0],(Int_t) strip);
	381	indexRange[k2+1]=TMath::Max(indexRange[k2+1],(Int_t) strip);
	382	} // dXCharge > 1 e-
	383	} // end if
b0f5e3fc	384	}
0315d466	385	//______________________________________________________________________
fd61217e	386	Int_t AliITSsimulationSSD::NumOfSteps(Double_t x, Double_t y, Double_t z,
0315d466	387	Double_t & dex,Double_t & dey,Double_t & dez){
	388	// number of steps
	389	// it also returns steps for each coord
	390	//AliITSsegmentationSSD *seg = new AliITSsegmentationSSD();
fd61217e	391
0315d466	392	Double_t step = 25E-4;
	393	//step = (Double_t) seg->GetStepSize(); // step size (cm)
	394	Int_t numOfSteps = (Int_t) (TMath::Sqrt(xx+yy+z*z)/step);
fd61217e	395
0315d466	396	if (numOfSteps < 1) numOfSteps = 1; // one step, at least
fd61217e	397
0315d466	398	// we could condition the stepping depending on the incident angle
	399	// of the track
	400	dex = x/numOfSteps;
	401	dey = y/numOfSteps;
	402	dez = z/numOfSteps;
b0f5e3fc	403
0315d466	404	return numOfSteps;
fd61217e	405	}
0315d466	406	//----------------------------------------------------------------------
	407	void AliITSsimulationSSD::GetList(Int_t label,Float_t **pList,
	408	Int_t *indexRange) {
	409	// loop over nonzero digits
	410	Int_t ix,globalIndex;
	411	Float_t signal=0.;
	412	Float_t highest,middle,lowest;
fd61217e	413	// printf("SPD-GetList: indexRange[0] indexRange[1] indexRange[2] indexRange[3] %d %d %d %d\n",indexRange[0], indexRange[1], indexRange[2], indexRange[3]);
fd61217e	414
0315d466	415	for(Int_t k=0; k<2; k++) {
	416	for(ix=indexRange[k2+0];ix<indexRange[k2+1]+1;ix++){
	417	if(indexRange[k2+0]<indexRange[k2+1])
	418	signal=fMapA2->GetSignal(k,ix);
fd61217e	419
0315d466	420	globalIndex = k*fNstrips+ix; // globalIndex starts from 0!
	421	if(!pList[globalIndex]){
	422	//
	423	//Create new list (6 elements-3 signals and 3 tracks+total sig)
	424	//
	425	pList[globalIndex] = new Float_t [6];
	426	// set list to -1
	427	*pList[globalIndex] = -2.;
	428	*(pList[globalIndex]+1) = -2.;
	429	*(pList[globalIndex]+2) = -2.;
	430	*(pList[globalIndex]+3) = 0.;
	431	*(pList[globalIndex]+4) = 0.;
	432	*(pList[globalIndex]+5) = 0.;
	433	*pList[globalIndex] = (float)label;
	434	*(pList[globalIndex]+3) = signal;
	435	}else{
	436	// check the signal magnitude
	437	highest = *(pList[globalIndex]+3);
	438	middle = *(pList[globalIndex]+4);
	439	lowest = *(pList[globalIndex]+5);
	440	signal -= (highest+middle+lowest);
	441	//
	442	// compare the new signal with already existing list
	443	//
	444	if(signal<lowest) continue; // neglect this track
	445	if (signal>highest){
	446	*(pList[globalIndex]+5) = middle;
	447	*(pList[globalIndex]+4) = highest;
	448	*(pList[globalIndex]+3) = signal;
	449	(pList[globalIndex]+2) = (pList[globalIndex]+1);
	450	(pList[globalIndex]+1) = pList[globalIndex];
	451	*pList[globalIndex] = label;
	452	}else if (signal>middle){
	453	*(pList[globalIndex]+5) = middle;
	454	*(pList[globalIndex]+4) = signal;
	455	(pList[globalIndex]+2) = (pList[globalIndex]+1);
	456	*(pList[globalIndex]+1) = label;
	457	}else{
	458	*(pList[globalIndex]+5) = signal;
	459	*(pList[globalIndex]+2) = label;
	460	} // end if
	461	} // end if
	462	} // end of loop pixels in x
	463	} // end of loop over pixels in z
fd61217e	464	}
0315d466	465	//----------------------------------------------------------------------
fd61217e	466	void AliITSsimulationSSD::ChargeToSignal(Float_t **pList) {
0315d466	467	// charge to signal
	468	AliITS aliITS = (AliITS)gAlice->GetModule("ITS");
	469	Float_t threshold = 0.;
	470	Int_t digits[3], tracks[3],hits[3],gi,j1;
	471	Float_t charges[3];
	472	Float_t signal,phys;
	473	Float_t noise[2] = {0.,0.};
	474
	475	fResponse->GetNoiseParam(noise[0],noise[1]);
fd61217e	476
0315d466	477	for(Int_t k=0;k<2;k++){ // both sides (0=Pside, 1=Nside)
	478
	479	// Threshold for zero-suppression
	480	// It can be defined in AliITSresponseSSD
	481	// threshold = (Float_t)fResponse->MinVal(k);
	482	// I prefer to think adjusting the threshold "manually", looking
	483	// at the scope, and considering noise standard deviation
	484	threshold = 4.0*noise[k]; // 4 times noise is a choice
	485	for(Int_t ix=0;ix<fNstrips;ix++){ // loop over strips
	486
	487	signal = (Float_t) fMapA2->GetSignal(k,ix);
	488
	489	gi =k*fNstrips+ix; // global index
	490	if (signal > threshold) {
	491	digits[0]=k;
	492	digits[1]=ix;
	493
	494	// convert to ADC signal
	495	// conversion factor are rather arbitrary (need tuning)
	496	// minimum ionizing particle--> ~30000 pairs--> ADC channel 50
	497	signal = signal*50.0/30000.0;
	498	if(signal>1000.) signal = 1000.0;//if exceeding, accumulate
	499	// last one
	500	digits[2]=(Int_t) signal;
	501
	502	//gi =k*fNstrips+ix; // global index
	503	for(j1=0;j1<3;j1++){
	504	if (pList[gi]) {
	505	tracks[j1] = (Int_t)(*(pList[gi]+j1));
	506	} else {
	507	tracks[j1]=-2; //noise
	508	} // end if pList
	509	charges[j1] = 0;
	510	} // end for j1
	511
	512	phys=0;
	513
	514	hits[0]=0;
	515	hits[1]=0;
	516	hits[2]=0;
	517	// finally add digit
	518	aliITS->AddSimDigit(2,phys,digits,tracks,hits,charges);
	519
	520	//if(pList[gi]) delete [] pList[gi];
	521	} // end if signal > threshold
	522	if(pList[gi]) delete [] pList[gi];
	523	} // end for ix
	524	} // end for k
	525	delete [] pList;
b0f5e3fc	526	}