Changeset 10111 for trunk

Timestamp:

01/19/11 20:08:56 (14 years ago)

Author:

tbretz

Message:

Forgot it in my commit 2011/01/07.

File:

• trunk/Mars/melectronics/MAvalanchePhotoDiode.h (modified) (2 diffs)

trunk/Mars/melectronics/MAvalanchePhotoDiode.h

@@ -6 +6 @@
 #endif
 
+#ifndef ROOT_TSortedList
+#include <TSortedList.h>
+#endif
+
+class Afterpulse : public TObject
+{
+private:
+    UInt_t  fCellIndex;  // Index of G-APD cell the afterpulse belongs to
+
+    Float_t fTime;       // Time at which the afterpulse avalanch broke through
+    Float_t fAmplitude;  // Amplitude (crosstalk!) the pulse produced
+
+    Int_t Compare(const TObject *obj) const
+    {
+        return static_cast<const Afterpulse*>(obj)->fTime>fTime ? -1 : 1;
+    }
+
+    Bool_t IsSortable() const { return kTRUE; }
+
+public:
+    Afterpulse(UInt_t idx, Float_t t) : fCellIndex(idx), fTime(t), fAmplitude(0) { }
+
+    UInt_t GetCellIndex() const { return fCellIndex; }
+
+    Float_t GetTime() const { return fTime; }
+    Float_t GetAmplitude() const { return fAmplitude; }
+
+    Float_t Process(APD &apd)
+    {
+        // Do not process afterpulses twice (e.g. HitRelative + IncreaseTime)
+        // This should not happen anyway
+        //        if (fAmplitude>0)
+        //            return fAmplitude;
+
+        const UInt_t nx  = apd.GetNumCellsX()+2;
+
+        const UInt_t x = fCellIndex%nx;
+        const UInt_t y = fCellIndex/nx;
+
+        fAmplitude = apd.HitCellImp(x, y, fTime);
+
+        return fAmplitude;
+    }
+};
+
 class APD : public TObject  // FIXME: Derive from TH2?
 {
+    friend class Afterpulse;
+
 private:
     TH2F fHist;
 
-    Float_t fCrosstalkProb;  // Probability that a converted photon creates another one in a neighboring cell
-    Float_t fDeadTime;       // Deadtime of a single cell after a hit
-    Float_t fRecoveryTime;   // Recoverytime after Deadtime (1-exp(-t/fRecoveryTime)
+    TSortedList fAfterpulses;   //! List of produced afterpulses
 
-    Float_t fTime;           // A user settable time of the system
+    Float_t fCrosstalkProb;     // Probability that a converted photon creates another one in a neighboring cell
+    Float_t fDeadTime;          // Deadtime of a single cell after a hit
+    Float_t fRecoveryTime;      // Recoverytime after Deadtime (1-exp(-t/fRecoveryTime)
+    Float_t fAfterpulseProb[2]; // Afterpulse probabilities
+    Float_t fAfterpulseTau[2];  // Afterpulse time constants
 
+    Float_t fTime;              // A user settable time of the system
+
+    // The implementation of the cell behaviour (crosstalk and afterpulses)
     Float_t HitCellImp(Int_t x, Int_t y, Float_t t=0);
+
+    // Processing of afterpulses
+    void GenerateAfterpulse(UInt_t cell, Int_t idx, Double_t charge, Double_t t);
+    void ProcessAfterpulses(Float_t time, Float_t dt);
+    void DeleteAfterpulses(Float_t time);
 
 public:
     APD(Int_t n, Float_t prob=0, Float_t dt=0, Float_t rt=0);
 
-    Float_t HitCell(Int_t x, Int_t y, Float_t t=0);
-    Float_t HitRandomCell(Float_t t=0);
-    Float_t HitRandomCellRelative(Float_t t=0) { return HitRandomCell(fTime+t); }
+    // --- Setter and Getter ----
 
-    void FillEmpty(Float_t t=0);
-    void FillRandom(Float_t rate, Float_t t=0);
+    // Set the afterpulse probability and time-constant of distribution 1 and 2
+    void SetAfterpulse1(Double_t p, Double_t tau) { fAfterpulseProb[0]=p; fAfterpulseTau[0]=tau; }
+    void SetAfterpulse2(Double_t p, Double_t tau) { fAfterpulseProb[1]=p; fAfterpulseTau[1]=tau; }
 
-    void Init(Float_t rate) { if (fTime<0) FillRandom(rate); else Relax(rate); }
+    // Set the afterpulse probability for distribution 1 and 2
+    void SetAfterpulseProb(Double_t p1, Double_t p2) { fAfterpulseProb[0]=p1; fAfterpulseProb[1]=p2; }
 
-    Int_t CountDeadCells(Float_t t=0) const;
-    Int_t CountRecoveringCells(Float_t t=0) const;
-
+    // Getter functions
     Float_t GetCellContent(Int_t x, Int_t y) const { return fHist.GetBinContent(x, y); }
     Int_t   GetNumCellsX() const { return fHist.GetNbinsX(); }
@@ -46 +101 @@
     Float_t GetLastHit() const { return fHist.GetMaximum(); }
 
-    void SetTime(Float_t tm) { fTime=tm; }
-    void IncreaseTime(Float_t dt) { fTime += dt; }
+    TSortedList &GetListOfAfterpulses() { return fAfterpulses; }
 
+    // Functions for easy production of statistics about the cells
+    Int_t CountDeadCells(Float_t t=0) const;
+    Int_t CountRecoveringCells(Float_t t=0) const;
+
+    // --- Lower level user interface ---
+
+    // Implementation to hit a specified or random cell
+    Float_t HitCell(Int_t x, Int_t y, Float_t t=0);
+    Float_t HitRandomCell(Float_t t=0);
+
+    // Functions to produce virgin chips or just effected by constant rates
+    void FillEmpty(Float_t t=0);
+    void FillRandom(Float_t rate, Float_t t=0);
+
+    // Produce random pulses with the given rate over a time dt.
+    // Processes afterpulses until the new time and deletes previous
+    // afterpulses.
     Float_t Evolve(Double_t freq, Double_t dt);
+
+    // Delete Afterpulses before fTime. This might be wanted after
+    // a call to Evolve or Relax to maintain memeory usage.
+    void DeleteAfterpulses() { DeleteAfterpulses(fTime); }
+
+    // --- High level user interface ---
+
+    // This fills a G-APD with a rough estimated state at a given time
+    // T=0. It then evolves the time over the ralaxation time. If the
+    // chip is not virgin (i.e. fTime<0) the random filling is omitted
+    void Init(Float_t rate) { if (fTime<0) FillRandom(rate); Relax(rate); ShiftTime(); }
+
+    // Shifts all times including fTime by dt backwards (adds -dt)
+    // This is convenient because you can set the current time (fTime) to 0
+    void ShiftTime(Double_t dt);
+    void ShiftTime() { ShiftTime(fTime); }
+
+    // Functions producing photons hitting cells. It is meant to add
+    // many photons with an arrival time t after fTime. The photons
+    // must be sorted in time first to ensure proper treatment of the
+    // afterpulses.
+    Float_t HitRandomCellRelative(Float_t t=0) { ProcessAfterpulses(fTime, t); return HitRandomCell(fTime+t); }
+
+    // Produce random pulses with a given frequency until the influence
+    // of the effects of the G-APD (relaxation time, afterpulses) are
+    // below the given threshold. (Calls Evolve())
+    // FIXME: Maybe the calculation of the relaxation time could be optimized?
     Float_t Relax(Double_t freq, Float_t threshold=0.001) { return Evolve(freq, GetRelaxationTime(threshold)); }
 
+    // Issue afterpulses until fTime+dt and set fTime to fTime+dt
+    // This is needed to create all afterpulses from external pulses
+    // and afterpulses until the time fTime+dt. This makes mainly
+    // the list of afterpulses complete until fTime+dt
+    void IncreaseTime(Float_t dt) { ProcessAfterpulses(fTime, dt); fTime += dt; }
+
+    // TObject
     void Draw(Option_t *o="") { fHist.Draw(o); }
     void DrawCopy(Option_t *o="") { fHist.DrawCopy(o); }