/************************************************************************** * 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. * **************************************************************************/ /* $Id$ */ // -------------------------- // Class AliMUONResponseV0 // -------------------------- // Implementation of Mathieson response // ... #include "AliMUONResponseV0.h" #include "AliLog.h" #include "AliMUON.h" #include "AliMUONConstants.h" #include "AliMUONDigit.h" #include "AliMUONGeometrySegmentation.h" #include "AliMUONGeometryTransformer.h" #include "AliMUONHit.h" #include "AliMUONSegmentation.h" #include "AliMpArea.h" #include "AliMpDEManager.h" #include "AliMpVPadIterator.h" #include "AliMpVSegmentation.h" #include "AliRun.h" #include "Riostream.h" #include "TVector2.h" #include #include ClassImp(AliMUONResponseV0) AliMUON* muon() { return static_cast(gAlice->GetModule("MUON")); } void Global2Local(Int_t detElemId, Double_t xg, Double_t yg, Double_t zg, Double_t& xl, Double_t& yl, Double_t& zl) { // ideally should be : // Double_t x,y,z; // AliMUONGeometry::Global2Local(detElemId,xg,yg,zg,x,y,z); // but while waiting for this geometry singleton, let's go through // AliMUON still. const AliMUONGeometryTransformer* transformer = muon()->GetGeometryTransformer(); transformer->Global2Local(detElemId,xg,yg,zg,xl,yl,zl); } AliMUONSegmentation* Segmentation() { static AliMUONSegmentation* segmentation = muon()->GetSegmentation(); return segmentation; } //__________________________________________________________________________ AliMUONResponseV0::AliMUONResponseV0() : AliMUONResponse(), fChargeSlope(0.0), fChargeSpreadX(0.0), fChargeSpreadY(0.0), fSigmaIntegration(0.0), fMaxAdc(0), fSaturation(0), fZeroSuppression(0), fChargeCorrel(0.0), fMathieson(new AliMUONMathieson), fChargeThreshold(1e-4) { // Normal constructor AliDebug(1,Form("Default ctor")); } //__________________________________________________________________________ AliMUONResponseV0::~AliMUONResponseV0() { AliDebug(1,""); delete fMathieson; } //______________________________________________________________________________ void AliMUONResponseV0::Print(Option_t*) const { // Printing cout << " ChargeSlope=" << fChargeSlope << " ChargeSpreadX,Y=" << fChargeSpreadX << fChargeSpreadY << " ChargeCorrelation=" << fChargeCorrel << endl; } //__________________________________________________________________________ void AliMUONResponseV0::SetSqrtKx3AndDeriveKx2Kx4(Float_t SqrtKx3) { // Set to "SqrtKx3" the Mathieson parameter K3 ("fSqrtKx3") // in the X direction, perpendicular to the wires, // and derive the Mathieson parameters K2 ("fKx2") and K4 ("fKx4") // in the same direction fMathieson->SetSqrtKx3AndDeriveKx2Kx4(SqrtKx3); } //__________________________________________________________________________ void AliMUONResponseV0::SetSqrtKy3AndDeriveKy2Ky4(Float_t SqrtKy3) { // Set to "SqrtKy3" the Mathieson parameter K3 ("fSqrtKy3") // in the Y direction, along the wires, // and derive the Mathieson parameters K2 ("fKy2") and K4 ("fKy4") // in the same direction fMathieson->SetSqrtKy3AndDeriveKy2Ky4(SqrtKy3); } //__________________________________________________________________________ Float_t AliMUONResponseV0::IntPH(Float_t eloss) const { // Calculate charge from given ionization energy loss Int_t nel; nel= Int_t(eloss*1.e9/27.4); Float_t charge=0; if (nel == 0) nel=1; for (Int_t i=1;i<=nel;i++) { Float_t arg=0.; while(!arg) arg = gRandom->Rndm(); charge -= fChargeSlope*TMath::Log(arg); } return charge; } //------------------------------------------- Float_t AliMUONResponseV0::IntXY(Int_t idDE, AliMUONGeometrySegmentation* segmentation) const { // Calculate charge on current pad according to Mathieson distribution return fMathieson->IntXY(idDE, segmentation); } //------------------------------------------- Int_t AliMUONResponseV0::DigitResponse(Int_t digit, AliMUONTransientDigit* /*where*/) const { // \deprecated method // Now part of the digitizer (where it belongs really), e.g. DigitizerV3 // // add white noise and do zero-suppression and signal truncation // Float_t meanNoise = gRandom->Gaus(1, 0.2); // correct noise for slat chambers; // one more field to add to AliMUONResponseV0 to allow different noises ???? // Float_t meanNoise = gRandom->Gaus(1., 0.2); // Float_t noise = gRandom->Gaus(0., meanNoise); Float_t noise = gRandom->Gaus(0., 1.0); digit += TMath::Nint(noise); if ( digit <= ZeroSuppression()) digit = 0; // if ( digit > MaxAdc()) digit=MaxAdc(); if ( digit > Saturation()) { digit=Saturation(); } return digit; } //_____________________________________________________________________________ Float_t AliMUONResponseV0::GetAnod(Float_t x) const { // // Return wire coordinate closest to x. // Int_t n = Int_t(x/Pitch()); Float_t wire = (x>0) ? n+0.5 : n-0.5; return Pitch()*wire; } //______________________________________________________________________________ void AliMUONResponseV0::DisIntegrate(const AliMUONHit& hit, TList& digits) { // // Go from 1 hit to a list of digits. // The energy deposition of that hit is first converted into charge // (in IntPH() method), and then this charge is dispatched on several // pads, according to the Mathieson distribution. // digits.Clear(); Int_t detElemId = hit.DetElemId(); // Width of the integration area Double_t dx = SigmaIntegration()*ChargeSpreadX(); Double_t dy = SigmaIntegration()*ChargeSpreadY(); // Use that (dx,dy) to specify the area upon which // we will iterate to spread charge into. Double_t x,y,z; Global2Local(detElemId,hit.X(),hit.Y(),hit.Z(),x,y,z); x = GetAnod(x); TVector2 hitPosition(x,y); AliMpArea area(hitPosition,TVector2(dx,dy)); // Get pulse height from energy loss. Float_t qtot = IntPH(hit.Eloss()); // Get the charge correlation between cathodes. Float_t currentCorrel = TMath::Exp(gRandom->Gaus(0.0,ChargeCorrel()/2.0)); for ( Int_t cath = 0; cath < 2; ++cath ) { Float_t qcath = qtot * ( cath == 0 ? currentCorrel : 1.0/currentCorrel); // Get an iterator to loop over pads, within the given area. const AliMpVSegmentation* seg = Segmentation()->GetMpSegmentation(detElemId,cath); AliMpVPadIterator* it = seg->CreateIterator(area); if (!it) { AliError(Form("Could not get iterator for detElemId %d",detElemId)); return; } // Start loop over pads. it->First(); if ( it->IsDone() ) { // Exceptional case : iterator is built, but is invalid from the start. AliMpPad pad = seg->PadByPosition(area.Position(),kFALSE); if ( pad.IsValid() ) { AliWarning(Form("Got an invalid iterator bug (area.Position() is within " " DE but the iterator is void) for detElemId %d cath %d", detElemId,cath)); } else { AliError(Form("Got an invalid iterator bug for detElemId %d cath %d." "Might be a bad hit ? area.Position()=(%e,%e) " "Dimensions()=(%e,%e)", detElemId,cath,area.Position().X(),area.Position().Y(), area.Dimensions().X(),area.Dimensions().Y())); } delete it; return; } while ( !it->IsDone() ) { // For each pad given by the iterator, compute the charge of that // pad, according to the Mathieson distribution. AliMpPad pad = it->CurrentItem(); TVector2 lowerLeft(hitPosition-pad.Position()-pad.Dimensions()); TVector2 upperRight(lowerLeft + pad.Dimensions()*2.0); Float_t qp = TMath::Abs(fMathieson->IntXY(lowerLeft.X(),lowerLeft.Y(), upperRight.X(),upperRight.Y())); Int_t icharge = Int_t(qp*qcath); if ( qp > fChargeThreshold ) { // If we're above threshold, then we create a digit, // and fill it with relevant information, including electronics. AliMUONDigit* d = new AliMUONDigit; d->SetDetElemId(detElemId); d->SetPadX(pad.GetIndices().GetFirst()); d->SetPadY(pad.GetIndices().GetSecond()); d->SetSignal(icharge); d->AddPhysicsSignal(d->Signal()); d->SetCathode(cath); d->SetElectronics(pad.GetLocation().GetFirst(), pad.GetLocation().GetSecond()); digits.Add(d); } it->Next(); } delete it; } }