1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
7 * Permission to use, copy, modify and distribute this software and its *
8 * documentation strictly for non-commercial purposes is hereby granted *
9 * without fee, provided that the above copyright notice appears in all *
10 * copies and that both the copyright notice and this permission notice *
11 * appear in the supporting documentation. The authors make no claims *
12 * about the suitability of this software for any purpose. It is *
13 * provided "as is" without express or implied warranty. *
14 **************************************************************************/
20 #include <Riostream.h>
21 #include <TObjArray.h>
22 #include "AliITSmodule.h"
23 #include "AliITSMapA2.h"
24 #include "AliITSpList.h"
25 #include "AliITSCalibrationSSD.h"
26 #include "AliITSsegmentationSSD.h"
27 //#include "AliITSdcsSSD.h"
29 #include "AliITShit.h"
30 #include "AliITSdigitSSD.h"
32 #include "AliITSgeom.h"
33 #include "AliITSsimulationSSD.h"
34 #include "AliITSTableSSD.h"
35 //#include "AliITSresponseSSD.h"
37 ClassImp(AliITSsimulationSSD)
38 ////////////////////////////////////////////////////////////////////////
40 // Author: Enrico Fragiacomo //
41 // enrico.fragiacomo@ts.infn.it //
42 // Last revised: march 2006 //
44 // AliITSsimulationSSD is the simulation of SSD. //
45 ////////////////////////////////////////////////////////////////////////
47 //----------------------------------------------------------------------
48 AliITSsimulationSSD::AliITSsimulationSSD():AliITSsimulation(),
60 // A default construction AliITSsimulationSSD class
62 //----------------------------------------------------------------------
63 AliITSsimulationSSD::AliITSsimulationSSD(AliITSDetTypeSim* dettyp):
64 AliITSsimulation(dettyp),
72 // AliITSDetTypeSim Pointer to the SSD dettype to be used
76 // A standard constructed AliITSsimulationSSD class
80 //----------------------------------------------------------------------
81 void AliITSsimulationSSD::Init(){
82 // Inilizer, Inilizes all of the variable as needed in a standard place.
84 // AliITSsegmentationSSD *seg Pointer to the SSD segmentation to be used
85 // AliITSCalibrationSSD *resp Pointer to the SSD responce class to be used
90 AliITSsegmentationSSD* seg = (AliITSsegmentationSSD*)GetSegmentationModel(2);
92 SetDriftVelocity(); // use default values in .h file
93 SetIonizeE(); // use default values in .h file
94 SetDiffConst(); // use default values in .h file
95 fpList = new AliITSpList(2,GetNStrips());
96 fMapA2 = new AliITSMapA2(seg);
98 //______________________________________________________________________
99 AliITSsimulationSSD& AliITSsimulationSSD::operator=(
100 const AliITSsimulationSSD &s){
103 if(this==&s) return *this;
105 // this->fDCS = new AliITSdcsSSD(*(s.fDCS));
106 this->fMapA2 = s.fMapA2;
107 this->fIonE = s.fIonE;
108 this->fDifConst[0] = s.fDifConst[0];
109 this->fDifConst[1] = s.fDifConst[1];
110 this->fDriftVel[0] = s.fDriftVel[0];
111 this->fDriftVel[1] = s.fDriftVel[1];
114 //______________________________________________________________________
115 AliITSsimulation& AliITSsimulationSSD::operator=(
116 const AliITSsimulation &s){
119 if(this==&s) return *this;
120 Error("AliITSsimulationSSD","Not allowed to make a = with "
121 "AliITSsimulationSSD Using default creater instead");
125 //______________________________________________________________________
126 AliITSsimulationSSD::AliITSsimulationSSD(const AliITSsimulationSSD &source):
127 AliITSsimulation(source){
132 //______________________________________________________________________
133 AliITSsimulationSSD::~AliITSsimulationSSD() {
138 //______________________________________________________________________
139 void AliITSsimulationSSD::InitSimulationModule(Int_t module,Int_t event){
140 // Creates maps to build the list of tracks for each sumable digit
142 // Int_t module // Module number to be simulated
143 // Int_t event // Event number to be simulated
149 SetModuleNumber(module);
150 SetEventNumber(event);
154 //______________________________________________________________________
155 void AliITSsimulationSSD::FinishSDigitiseModule(){
156 // Does the Sdigits to Digits work
164 FillMapFrompList(fpList); // need to check if needed here or not????
165 SDigitToDigit(fModule,fpList);
169 //______________________________________________________________________
170 void AliITSsimulationSSD::DigitiseModule(AliITSmodule *mod,Int_t,Int_t) {
171 // Digitizes hits for one SSD module
172 SetModuleNumber(mod->GetIndex());
174 HitsToAnalogDigits(mod,fpList);
175 SDigitToDigit(GetModuleNumber(),fpList);
180 //______________________________________________________________________
181 void AliITSsimulationSSD::SDigitiseModule(AliITSmodule *mod,Int_t,Int_t) {
182 // Produces Summable/Analog digits and writes them to the SDigit tree.
184 HitsToAnalogDigits(mod,fpList);
186 WriteSDigits(fpList);
191 //______________________________________________________________________
192 void AliITSsimulationSSD::SDigitToDigit(Int_t module,AliITSpList *pList){
193 // Takes the pList and finishes the digitization.
195 ApplyNoise(pList,module);
196 ApplyCoupling(pList,module);
197 ApplyDeadChannels(module);
199 ChargeToSignal(module,pList);
201 //______________________________________________________________________
202 void AliITSsimulationSSD::HitsToAnalogDigits(AliITSmodule *mod,
204 // Loops over all hits to produce Analog/floating point digits. This
205 // is also the first task in producing standard digits.
206 Int_t lasttrack = -2;
208 Double_t x0=0.0, y0=0.0, z0=0.0;
209 Double_t x1=0.0, y1=0.0, z1=0.0;
211 Int_t module = mod->GetIndex();
213 AliITSsegmentationSSD* seg = (AliITSsegmentationSSD*)GetSegmentationModel(2);
215 TObjArray *hits = mod->GetHits();
216 Int_t nhits = hits->GetEntriesFast();
217 if (nhits<=0) return;
218 AliITSTableSSD * tav = new AliITSTableSSD(GetNStrips());
219 module = mod->GetIndex();
220 if ( mod->GetLayer() == 6 ) seg->SetLayer(6);
221 if ( mod->GetLayer() == 5 ) seg->SetLayer(5);
222 for(Int_t i=0; i<nhits; i++) {
223 // LineSegmentL returns 0 if the hit is entering
224 // If hits is exiting returns positions of entering and exiting hits
225 // Returns also energy loss
228 cout << mod->GetHit(i)->GetXL() << " "<<mod->GetHit(i)->GetYL();
229 cout << " " << mod->GetHit(i)->GetZL();
232 if (mod->LineSegmentL(i, x0, x1, y0, y1, z0, z1, de, idtrack)) {
233 HitToDigit(module, x0, y0, z0, x1, y1, z1, de,tav);
234 if (lasttrack != idtrack || i==(nhits-1)) {
235 GetList(idtrack,i,module,pList,tav);
239 } // end loop over hits
243 //----------------------------------------------------------------------
244 void AliITSsimulationSSD::HitToDigit(Int_t module, Double_t x0, Double_t y0,
245 Double_t z0, Double_t x1, Double_t y1,
246 Double_t z1, Double_t de,
247 AliITSTableSSD *tav) {
249 // hit to digit conversion
251 AliITSsegmentationSSD* seg = (AliITSsegmentationSSD*)GetSegmentationModel(2);
252 // Turns hits in SSD module into one or more digits.
253 Float_t tang[2] = {0.0,0.0};
254 seg->Angles(tang[0], tang[1]);//stereo<<->tan(stereo)~=stereo
256 Double_t dex=0.0, dey=0.0, dez=0.0;
257 Double_t pairs; // pair generation energy per step.
258 Double_t sigma[2] = {0.,0.};// standard deviation of the diffusion gaussian
259 Double_t tdrift[2] = {0.,0.}; // time of drift
261 Double_t inf[2], sup[2], par0[2];
263 // Steps in the module are determined "manually" (i.e. No Geant)
264 // NumOfSteps divide path between entering and exiting hits in steps
265 Int_t numOfSteps = NumOfSteps(x1, y1, z1, dex, dey, dez);
266 // Enery loss is equally distributed among steps
268 pairs = de/GetIonizeE(); // e-h pairs generated
269 for(Int_t j=0; j<numOfSteps; j++) { // stepping
270 x = x0 + (j+0.5)*dex;
271 y = y0 + (j+0.5)*dey;
272 if ( y > (seg->Dy()/2+10)*1.0E-4 ) {
273 // check if particle is within the detector
274 Warning("HitToDigit",
275 "hit out of detector y0=%e,y=%e,dey=%e,j =%e module=%d",
279 z = z0 + (j+0.5)*dez;
280 if(GetDebug(4)) cout <<"HitToDigit "<<x<<" "<<y<<" "<<z<< " "
281 <<dex<<" "<<dey<<" "<<dez<<endl;
282 // calculate drift time
283 // y is the minimum path
284 tdrift[0] = (y+(seg->Dy()*1.0E-4)/2)/GetDriftVelocity(0);
285 tdrift[1] = ((seg->Dy()*1.0E-4)/2-y)/GetDriftVelocity(1);
287 for(Int_t k=0; k<2; k++) { // both sides remember: 0=Pside 1=Nside
289 tang[k]=TMath::Tan(tang[k]);
291 // w is the coord. perpendicular to the strips
292 Float_t xp=x*1.e+4,zp=z*1.e+4; // microns
293 seg->GetPadTxz(xp,zp);
294 if(k==0) w = xp; // P side strip number
295 else w = zp; // N side strip number
297 if((w<(-0.5)) || (w>(GetNStrips()-0.5))) {
298 // this check rejects hits in regions not covered by strips
299 // 0.5 takes into account boundaries
300 if(GetDebug(4)) cout << "x,z="<<x<<","<<z<<" w="<<w
301 <<" Nstrips="<<GetNStrips()<<endl;
302 return; // There are dead region on the SSD sensitive volume.
305 // sigma is the standard deviation of the diffusion gaussian
306 if(tdrift[k]<0) return;
307 sigma[k] = TMath::Sqrt(2*GetDiffConst(k)*tdrift[k]);
308 sigma[k] /= (GetStripPitch()*1.0E-4); //units of Pitch
310 Error("HitToDigit"," sigma[%d]=0",k);
315 // we integrate the diffusion gaussian from -3sigma to 3sigma
316 inf[k] = w - 3*sigma[k]; // 3 sigma from the gaussian average
317 sup[k] = w + 3*sigma[k]; // 3 sigma from the gaussian average
318 // IntegrateGaussian does the actual
319 // integration of diffusion gaussian
320 IntegrateGaussian(k, par0[k], w, sigma[k], inf[k], sup[k],tav);
321 } // end for loop over side (0=Pside, 1=Nside)
325 //______________________________________________________________________
326 void AliITSsimulationSSD::ApplyNoise(AliITSpList *pList,Int_t module){
329 Double_t signal,noise;
330 AliITSCalibrationSSD* res =(AliITSCalibrationSSD*)GetCalibrationModel(module);
333 for(ix=0;ix<GetNStrips();ix++){ // loop over strips
336 noise = (Double_t) gRandom->Gaus(0,res->GetNoiseP().At(ix));
338 // need to calibrate noise
339 // NOTE. noise from the calibration database comes uncalibrated,
340 // it needs to be calibrated in order to be added
341 // to the signal. It will be decalibrated later on together with the noise
342 noise *= (Double_t) res->GetGainP(ix);
344 // noise comes in ADC channels from the calibration database
345 // It needs to be converted back to electronVolts
346 noise /= res->GetDEvToADC(1.);
348 // Finally, noise is added to the signal
349 signal = noise + fMapA2->GetSignal(0,ix);//get signal from map
350 fMapA2->SetHit(0,ix,signal); // give back signal to map
351 if(signal>0.0) pList->AddNoise(0,ix,module,noise);
355 for(ix=0;ix<GetNStrips();ix++){ // loop over strips
356 noise = (Double_t) gRandom->Gaus(0,res->GetNoiseN().At(ix));// give noise to signal
357 noise *= (Double_t) res->GetGainN(ix);
358 noise /= res->GetDEvToADC(1.);
359 signal = noise + fMapA2->GetSignal(1,ix);//get signal from map
360 fMapA2->SetHit(1,ix,signal); // give back signal to map
361 if(signal>0.0) pList->AddNoise(1,ix,module,noise);
365 //______________________________________________________________________
366 void AliITSsimulationSSD::ApplyCoupling(AliITSpList *pList,Int_t module) {
367 // Apply the effect of electronic coupling between channels
370 AliITSCalibrationSSD* res =(AliITSCalibrationSSD*)GetCalibrationModel(module);
372 Double_t *contrLeft = new Double_t[GetNStrips()];
373 Double_t *contrRight = new Double_t[GetNStrips()];
376 for(ix=0;ix<GetNStrips();ix++){
377 if(ix>0) contrLeft[ix] = fMapA2->GetSignal(0,ix-1)*res->GetCouplingPL();
378 else contrLeft[ix] = 0.0;
379 if(ix<(GetNStrips()-1)) contrRight[ix] = fMapA2->GetSignal(0,ix+1)*res->GetCouplingPR();
380 else contrRight[ix] = 0.0;
381 } // loop over strips
383 for(ix=0;ix<GetNStrips();ix++){
384 signal = contrLeft[ix] + contrRight[ix] - res->GetCouplingPL() * fMapA2->GetSignal(0,ix)
385 - res->GetCouplingPR() * fMapA2->GetSignal(0,ix);
386 fMapA2->AddSignal(0,ix,signal);
387 if(signal>0.0) pList->AddNoise(0,ix,module,signal);
388 } // loop over strips
391 for(ix=0;ix<GetNStrips();ix++){
392 if(ix>0) contrLeft[ix] = fMapA2->GetSignal(1,ix-1)*res->GetCouplingNL();
393 else contrLeft[ix] = 0.0;
394 if(ix<(GetNStrips()-1)) contrRight[ix] = fMapA2->GetSignal(1,ix+1)*res->GetCouplingNR();
395 else contrRight[ix] = 0.0;
396 } // loop over strips
398 for(ix=0;ix<GetNStrips();ix++){
399 signal = contrLeft[ix] + contrRight[ix] - res->GetCouplingNL() * fMapA2->GetSignal(0,ix)
400 - res->GetCouplingNR() * fMapA2->GetSignal(0,ix);
401 fMapA2->AddSignal(1,ix,signal);
402 if(signal>0.0) pList->AddNoise(1,ix,module,signal);
403 } // loop over strips
407 delete [] contrRight;
410 //______________________________________________________________________
411 void AliITSsimulationSSD::ApplyDeadChannels(Int_t module) {
412 // Kill dead channels setting gain to zero
416 AliITSCalibrationSSD* res = (AliITSCalibrationSSD*)GetCalibrationModel(module);
418 deadentries = res->GetDeadPChannelsList().GetSize();
419 //cout<<module<<" "<<deadentries<<endl;
420 for(Int_t i=0; i<deadentries; i++) {
421 res->AddGainP(res->GetDeadPChannelsList().At(i),0.0);
424 deadentries = res->GetDeadNChannelsList().GetSize();
425 for(Int_t i=0; i<deadentries; i++) {
426 res->AddGainN(res->GetDeadNChannelsList().At(i),0.0);
431 //______________________________________________________________________
432 Float_t AliITSsimulationSSD::F(Float_t av, Float_t x, Float_t s) {
433 // Computes the integral of a gaussian using Error Function
434 Float_t sqrt2 = TMath::Sqrt(2.0);
435 Float_t sigm2 = sqrt2*s;
438 integral = 0.5 * TMath::Erf( (x - av) / sigm2);
441 //______________________________________________________________________
442 void AliITSsimulationSSD::IntegrateGaussian(Int_t k,Double_t par, Double_t w,
444 Double_t inf, Double_t sup,
445 AliITSTableSSD *tav) {
446 // integrate the diffusion gaussian
447 // remind: inf and sup are w-3sigma and w+3sigma
448 // we could define them here instead of passing them
449 // this way we are free to introduce asimmetry
451 Double_t a=0.0, b=0.0;
452 Double_t dXCharge1 = 0.0, dXCharge2 = 0.0;
453 // dXCharge1 and 2 are the charge to two neighbouring strips
454 // Watch that we only involve at least two strips
455 // Numbers greater than 2 of strips in a cluster depend on
456 // geometry of the track and delta rays, not charge diffusion!
458 Double_t strip = TMath::Floor(w); // closest strip on the left
460 if ( TMath::Abs((strip - w)) < 0.5) {
461 // gaussian mean is closer to strip on the left
462 a = inf; // integration starting point
463 if((strip+0.5)<=sup) {
464 // this means that the tail of the gaussian goes beyond
465 // the middle point between strips ---> part of the signal
466 // is given to the strip on the right
467 b = strip + 0.5; // integration stopping point
468 dXCharge1 = F( w, b, sigma) - F(w, a, sigma);
469 dXCharge2 = F( w, sup, sigma) - F(w ,b, sigma);
471 // this means that all the charge is given to the strip on the left
473 dXCharge1 = 0.9973; // gaussian integral at 3 sigmas
476 dXCharge1 = par * dXCharge1;// normalize by mean of number of carriers
477 dXCharge2 = par * dXCharge2;
479 // for the time being, signal is the charge
480 // in ChargeToSignal signal is converted in ADC channel
481 fMapA2->AddSignal(k,(Int_t)strip,dXCharge1);
482 tav->Add(k,(Int_t)strip);
483 if(((Int_t) strip) < (GetNStrips()-1)) {
484 // strip doesn't have to be the last (remind: last=GetNStrips()-1)
485 // otherwise part of the charge is lost
486 fMapA2->AddSignal(k,((Int_t)strip+1),dXCharge2);
487 tav->Add(k,((Int_t)(strip+1)));
490 // gaussian mean is closer to strip on the right
491 strip++; // move to strip on the rigth
492 b = sup; // now you know where to stop integrating
493 if((strip-0.5)>=inf) {
494 // tail of diffusion gaussian on the left goes left of
495 // middle point between strips
496 a = strip - 0.5; // integration starting point
497 dXCharge1 = F(w, b, sigma) - F(w, a, sigma);
498 dXCharge2 = F(w, a, sigma) - F(w, inf, sigma);
501 dXCharge1 = 0.9973; // gaussian integral at 3 sigmas
504 dXCharge1 = par * dXCharge1; // normalize by means of carriers
505 dXCharge2 = par * dXCharge2;
506 // for the time being, signal is the charge
507 // in ChargeToSignal signal is converted in ADC channel
508 fMapA2->AddSignal(k,(Int_t)strip,dXCharge1);
509 tav->Add(k,(Int_t)strip);
510 if(((Int_t) strip) > 0) {
511 // strip doesn't have to be the first
512 // otherwise part of the charge is lost
513 fMapA2->AddSignal(k,((Int_t)strip-1),dXCharge2);
514 tav->Add(k,((Int_t)(strip-1)));
518 //______________________________________________________________________
519 Int_t AliITSsimulationSSD::NumOfSteps(Double_t x, Double_t y, Double_t z,
520 Double_t &dex,Double_t &dey,
523 // it also returns steps for each coord
524 //AliITSsegmentationSSD *seg = new AliITSsegmentationSSD();
526 Double_t step = 25E-4;
527 //step = (Double_t) seg->GetStepSize(); // step size (cm)
528 Int_t numOfSteps = (Int_t) (TMath::Sqrt(x*x+y*y+z*z)/step);
530 if (numOfSteps < 1) numOfSteps = 1; // one step, at least
533 // we could condition the stepping depending on the incident angle
541 //----------------------------------------------------------------------
542 void AliITSsimulationSSD::GetList(Int_t label,Int_t hit,Int_t mod,
543 AliITSpList *pList,AliITSTableSSD *tav) {
544 // loop over nonzero digits
548 for(Int_t k=0; k<2; k++) {
551 signal = fMapA2->GetSignal(k,ix);
555 } // end if signal==0.0
556 // check the signal magnitude
557 for(i=0;i<pList->GetNSignals(k,ix);i++){
558 signal -= pList->GetTSignal(k,ix,i);
560 // compare the new signal with already existing list
561 if(signal>0)pList->AddSignal(k,ix,label,hit,mod,signal);
563 } // end of loop on strips
564 } // end of loop on P/N side
567 //----------------------------------------------------------------------
568 void AliITSsimulationSSD::ChargeToSignal(Int_t module,AliITSpList *pList) {
570 static AliITS *aliITS = (AliITS*)gAlice->GetModule("ITS");
571 Float_t threshold = 0.;
572 Int_t size = AliITSdigitSSD::GetNTracks();
573 Int_t * digits = new Int_t[size];
574 Int_t * tracks = new Int_t[size];
575 Int_t * hits = new Int_t[size];
577 Float_t charges[3] = {0.0,0.0,0.0};
579 AliITSCalibrationSSD* res =(AliITSCalibrationSSD*)GetCalibrationModel(module);
581 for(Int_t k=0;k<2;k++){ // both sides (0=Pside, 1=Nside)
582 for(Int_t ix=0;ix<GetNStrips();ix++){ // loop over strips
584 // if strip is dead -> gain=0
585 if( ((k==0)&&(res->GetGainP(ix)==0)) || ((k==1)&&(res->GetGainN(ix)==0))) continue;
587 // signal has to be uncalibrated
588 // In real life, gains are supposed to be calculated from calibration runs,
589 // stored in the calibration DB and used in the reconstruction
590 // (see AliITSClusterFinderSSD.cxx)
591 if(k==0) signal /= res->GetGainP(ix);
592 else signal /= res->GetGainN(ix);
594 // signal is converted in unit of ADC
595 signal = res->GetDEvToADC(fMapA2->GetSignal(k,ix));
596 if(signal>4096.) signal = 4096.;//if exceeding, accumulate last one
598 // threshold for zero suppression is set on the basis of the noise
599 // A good value is 3*sigma_noise
600 if(k==0) threshold = res->GetNoiseP().At(ix);
601 else threshold = res->GetNoiseN().At(ix);
602 threshold *= res->GetZSThreshold(); // threshold at 3 sigma noise
603 if(signal < threshold) continue;
607 digits[2] = TMath::Nint(signal);
608 for(j1=0;j1<size;j1++)if(j1<pList->GetNEntries()){
609 // only three in digit.
610 tracks[j1] = pList->GetTrack(k,ix,j1);
611 hits[j1] = pList->GetHit(k,ix,j1);
617 aliITS->AddSimDigit(2,0,digits,tracks,hits,charges);
624 //______________________________________________________________________
625 void AliITSsimulationSSD::WriteSDigits(AliITSpList *pList){
626 // Fills the Summable digits Tree
628 static AliITS *aliITS = (AliITS*)gAlice->GetModule("ITS");
630 pList->GetMaxMapIndex(ni,nj);
631 for(i=0;i<ni;i++)for(j=0;j<nj;j++){
632 if(pList->GetSignalOnly(i,j)>0.0){
633 aliITS->AddSumDigit(*(pList->GetpListItem(i,j)));
634 if(GetDebug(4)) cout << "pListSSD: "<<*(pList->GetpListItem(i,j))
640 //______________________________________________________________________
641 void AliITSsimulationSSD::FillMapFrompList(AliITSpList *pList){
642 // Fills fMap2A from the pList of Summable digits
645 for(k=0;k<2;k++)for(ix=0;ix<GetNStrips();ix++)
646 fMapA2->AddSignal(k,ix,pList->GetSignal(k,ix));
649 //______________________________________________________________________
650 void AliITSsimulationSSD::Print(ostream *os){
651 //Standard output format for this class
653 //AliITSsimulation::Print(os);
655 *os << fDifConst[0] <<","<< fDifConst[1] <<",";
656 *os << fDriftVel[0] <<","<< fDriftVel[1];
657 //*os <<","; fDCS->Print(os);
658 //*os <<","; fMapA2->Print(os);
660 //______________________________________________________________________
661 void AliITSsimulationSSD::Read(istream *is){
662 // Standard output streaming function.
664 //AliITSsimulation::Read(is);
666 *is >> fDifConst[0] >> fDifConst[1];
667 *is >> fDriftVel[0] >> fDriftVel[1];
671 //______________________________________________________________________
672 ostream &operator<<(ostream &os,AliITSsimulationSSD &source){
673 // Standard output streaming function.
678 //______________________________________________________________________
679 istream &operator>>(istream &os,AliITSsimulationSSD &source){
680 // Standard output streaming function.
685 //______________________________________________________________________