/************************************************************************** * 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. * **************************************************************************/ /* $Id$ */ ////////////////////////////////////////////////////// // Calibration class for set:ITS // // Specific subdetector implementation is done in // // AliITSCalibrationSPD // // AliITSCalibrationSDD // // AliITSCalibrationSSD // ////////////////////////////////////////////////////// #include #include #include "AliITSCalibration.h" #include "AliLog.h" ClassImp(AliITSCalibration) //______________________________________________________________________ AliITSCalibration::AliITSCalibration(): TObject(), fDataType(), fdv(0.000375), fN(0.), fT(300.), fGeVcharge(0.), fResponse(){ // Default Constructor (300 microns and 80 volts) SetGeVToCharge(); fResponse = 0; } //______________________________________________________________________ AliITSCalibration::AliITSCalibration(Double_t thickness): TObject(), fDataType(), fdv(0.), fN(0.), fT(300.), fGeVcharge(0.), fResponse(){ // Default Constructor fdv = thickness/80.0; // 80 volts. SetGeVToCharge(); fResponse = 0; } //______________________________________________________________________ AliITSCalibration::AliITSCalibration(const AliITSCalibration &ob): TObject(ob), fDataType(ob.fDataType), fdv(ob.fdv), fN(ob.fN), fT(ob.fT), fGeVcharge(ob.fGeVcharge), fResponse(ob.fResponse) { // Copy constructor } /* //______________________________________________________________________________ AliITSCalibration& AliITSCalibration::operator= (const AliITSCalibration& source) { // Asignment operator this->~AliITSCalibration(); new(this) AliITSCalibration(source); return *this; } */ //______________________________________________________________________ Double_t AliITSCalibration::MobilityElectronSiEmp() const { // Computes the electron mobility in cm^2/volt-sec. Taken from SILVACO // International ATLAS II, 2D Device Simulation Framework, User Manual // Chapter 5 Equation 5-6. An empirical function for low-field mobiliity // in silicon at different tempeatures. // Inputs: // none. // Output: // none. // Return: // The Mobility of electrons in Si at a give temprature and impurity // concentration. [cm^2/Volt-sec] const Double_t km0 = 55.24; // cm^2/Volt-sec const Double_t km1 = 7.12E+08; // cm^2 (degree K)^2.3 / Volt-sec const Double_t kN0 = 1.072E17; // #/cm^3 const Double_t kT0 = 300.; // degree K. const Double_t keT0 = -2.3; // Power of Temp. const Double_t keT1 = -3.8; // Power of Temp. const Double_t keN = 0.73; // Power of Dopent Consentrations Double_t m; Double_t tT = fT,nN = fN; if(nN<=0.0){ // Simple case. if(tT==300.) return 1350.0; // From Table 5-1 at consentration 1.0E14. m = km1*TMath::Power(tT,keT0); return m; } // if nN<=0.0 m = km1*TMath::Power(tT,keT0) - km0; m /= 1.0 + TMath::Power(tT/kT0,keT1)*TMath::Power(nN/kN0,keN); m += km0; return m; } //______________________________________________________________________ Double_t AliITSCalibration::MobilityHoleSiEmp() const { // Computes the Hole mobility in cm^2/volt-sec. Taken from SILVACO // International ATLAS II, 2D Device Simulation Framework, User Manual // Chapter 5 Equation 5-7 An empirical function for low-field mobiliity // in silicon at different tempeatures. // Inputs: // none. // Output: // none. // Return: // The Mobility of Hole in Si at a give temprature and impurity // concentration. [cm^2/Volt-sec] const Double_t km0a = 49.74; // cm^2/Volt-sec const Double_t km0b = 49.70; // cm^2/Volt-sec const Double_t km1 = 1.35E+08; // cm^2 (degree K)^2.3 / Volt-sec const Double_t kN0 = 1.606E17; // #/cm^3 const Double_t kT0 = 300.; // degree K. const Double_t keT0 = -2.2; // Power of Temp. const Double_t keT1 = -3.7; // Power of Temp. const Double_t keN = 0.70; // Power of Dopent Consentrations Double_t m; Double_t tT = fT,nN = fN; if(nN<=0.0){ // Simple case. if(tT==300.) return 495.0; // From Table 5-1 at consentration 1.0E14. m = km1*TMath::Power(tT,keT0) + km0a-km0b; return m; } // if nN<=0.0 m = km1*TMath::Power(tT,keT0) - km0b; m /= 1.0 + TMath::Power(tT/kT0,keT1)*TMath::Power(nN/kN0,keN); m += km0a; return m; } //______________________________________________________________________ Double_t AliITSCalibration::DiffusionCoefficientElectron() const { // Computes the Diffusion coefficient for electrons in cm^2/sec. Taken // from SILVACO International ATLAS II, 2D Device Simulation Framework, // User Manual Chapter 5 Equation 5-53. Einstein relations for diffusion // coefficient. Note: 1 cm^2/sec = 10 microns^2/nanosec. // Inputs: // none. // Output: // none. // Return: // The Diffusion Coefficient of electrons in Si at a give temprature // and impurity concentration. [cm^2/sec] // const Double_t kb = 1.3806503E-23; // Joules/degree K // const Double_t qe = 1.60217646E-19; // Coulumbs. const Double_t kbqe = 8.617342312E-5; // Volt/degree K Double_t m = MobilityElectronSiEmp(); Double_t tT = fT; return m*kbqe*tT; // [cm^2/sec] } //______________________________________________________________________ Double_t AliITSCalibration::DiffusionCoefficientHole() const { // Computes the Diffusion coefficient for Holes in cm^2/sec. Taken // from SILVACO International ATLAS II, 2D Device Simulation Framework, // User Manual Chapter 5 Equation 5-53. Einstein relations for diffusion // coefficient. Note: 1 cm^2/sec = 10 microns^2/nanosec. // Inputs: // none. // Output: // none. // Return: // The Defusion Coefficient of Hole in Si at a give temprature and // impurity concentration. [cm^2/sec] // and impurity concentration. [cm^2/sec] // const Double_t kb = 1.3806503E-23; // Joules/degree K // const Double_t qe = 1.60217646E-19; // Coulumbs. const Double_t kbqe = 8.617342312E-5; // Volt/degree K Double_t m = MobilityHoleSiEmp(); Double_t tT = fT; return m*kbqe*tT; // [cm^2/sec] } //______________________________________________________________________ Double_t AliITSCalibration::SpeedElectron() const { // Computes the average speed for electrons in Si under the low-field // approximation. [cm/sec]. // Inputs: // none. // Output: // none. // Return: // The speed the holes are traveling at due to the low field applied. // [cm/sec] Double_t m = MobilityElectronSiEmp(); return m/fdv; // [cm/sec] } //______________________________________________________________________ Double_t AliITSCalibration::SpeedHole() const { // Computes the average speed for Holes in Si under the low-field // approximation.[cm/sec]. // Inputs: // none. // Output: // none. // Return: // The speed the holes are traveling at due to the low field applied. // [cm/sec] Double_t m = MobilityHoleSiEmp(); return m/fdv; // [cm/sec] } //______________________________________________________________________ Double_t AliITSCalibration::SigmaDiffusion3D(Double_t l) const { // Returns the Gaussian sigma^2 == [cm^2] due to the // defusion of electrons or holes through a distance l [cm] caused // by an applied voltage v [volt] through a distance d [cm] in any // material at a temperature T [degree K]. The sigma diffusion when // expressed in terms of the distance over which the diffusion // occures, l=time/speed, is independent of the mobility and therefore // the properties of the material. The charge distributions is given by // n = exp(-r^2/4Dt)/(4piDt)^1.5. From this = 6Dt where D=mkT/e // (m==mobility, k==Boltzman's constant, T==temparature, e==electric // charge. and vel=m*v/d. consiquently sigma^2=6kTdl/ev. // Inputs: // Double_t l Distance the charge has to travel. // Output: // none. // Return: // The Sigma due to the diffution of electrons. [cm] const Double_t kcon = 5.17040258E-04; // == 6k/e [J/col or volts] return TMath::Sqrt(kcon*fT*fdv*l); // [cm] } //______________________________________________________________________ Double_t AliITSCalibration::SigmaDiffusion2D(Double_t l) const { // Returns the Gaussian sigma^2 == [cm^2] due to the defusion // of electrons or holes through a distance l [cm] caused by an applied // voltage v [volt] through a distance d [cm] in any material at a // temperature T [degree K]. The sigma diffusion when expressed in terms // of the distance over which the diffusion occures, l=time/speed, is // independent of the mobility and therefore the properties of the // material. The charge distributions is given by // n = exp(-r^2/4Dt)/(4piDt)^1.5. From this = 4Dt where D=mkT/e // (m==mobility, k==Boltzman's constant, T==temparature, e==electric // charge. and vel=m*v/d. consiquently sigma^2=4kTdl/ev. // Inputs: // Double_t l Distance the charge has to travel. // Output: // none. // Return: // The Sigma due to the diffution of electrons. [cm] const Double_t kcon = 3.446935053E-04; // == 4k/e [J/col or volts] return TMath::Sqrt(kcon*fT*fdv*l); // [cm] } //______________________________________________________________________ Double_t AliITSCalibration::SigmaDiffusion1D(Double_t l) const { // Returns the Gaussian sigma^2 == [cm^2] due to the defusion // of electrons or holes through a distance l [cm] caused by an applied // voltage v [volt] through a distance d [cm] in any material at a // temperature T [degree K]. The sigma diffusion when expressed in terms // of the distance over which the diffusion occures, l=time/speed, is // independent of the mobility and therefore the properties of the // material. The charge distributions is given by // n = exp(-r^2/4Dt)/(4piDt)^1.5. From this = 2Dt where D=mkT/e // (m==mobility, k==Boltzman's constant, T==temparature, e==electric // charge. and vel=m*v/d. consiquently sigma^2=2kTdl/ev. // Inputs: // Double_t l Distance the charge has to travel. // Output: // none. // Return: // The Sigma due to the diffution of electrons. [cm] const Double_t kcon = 1.723467527E-04; // == 2k/e [J/col or volts] return TMath::Sqrt(kcon*fT*fdv*l); // [cm] } //---------------------------------------------------------------------- Double_t AliITSCalibration::DepletedRegionThicknessA(Double_t dopCons, Double_t voltage, Double_t elecCharge, Double_t voltBuiltIn)const{ // Computes the thickness of the depleted region in Si due to the // application of an external bias voltage. From the Particle Data // Book, 28.8 Silicon semiconductor detectors equation 28.19 (2004) // Physics Letters B "Review of Particle Physics" Volume 592, Issue 1-4 // July 15 2004, ISSN 0370-2693 page 263. First equation. // Inputs: // Double_t dopCons "N" doping concentration // Double_t voltage "V" external bias voltage // Double_t elecCharge "e" electronic charge // Double_t voltBuiltIn=0.5 "V_bi" "built-in" Voltage (~0.5V for // resistivities typically used in detectors) // Output: // none. // Return: // The thickness of the depleted region return TMath::Sqrt(2.0*(voltage+voltBuiltIn)/(dopCons*elecCharge)); } //---------------------------------------------------------------------- Double_t AliITSCalibration::DepletedRegionThicknessB(Double_t resist, Double_t voltage, Double_t mobility, Double_t voltBuiltIn, Double_t dielConst)const{ // Computes the thickness of the depleted region in Si due to the // application of an external bias voltage. From the Particle Data // Book, 28.8 Silicon semiconductor detectors equation 28.19 (2004) // Physics Letters B "Review of Particle Physics" Volume 592, Issue 1-4 // July 15 2004, ISSN 0370-2693 page 263. Second Equation. // Inputs: // Double_t resist "rho" resistivity (typically 1-10 kOhm cm) // Double_t voltage "V" external bias voltage // Double_t mobility "mu" charge carrier mobility // (electons 1350, holes 450 cm^2/V/s) // Double_t voltBuiltIn=0.5 "V_bi" "built-in" Voltage (~0.5V for // resistivities typically used in detectors) // Double_t dielConst=1.E-12 "epsilon" dielectric constant = 11.9 * // (permittivity of free space) or ~ 1 pF/cm // Output: // none. // Return: // The thickness of the depleted region return TMath::Sqrt(2.8*resist*mobility*dielConst*(voltage+voltBuiltIn)); } //---------------------------------------------------------------------- Double_t AliITSCalibration::ReverseBiasCurrent(Double_t temp, Double_t revBiasCurT1, Double_t tempT1, Double_t energy)const{ // Computes the temperature dependance of the reverse bias current // of Si detectors. From the Particle Data // Book, 28.8 Silicon semiconductor detectors equation 28.21 (2004) // Physics Letters B "Review of Particle Physics" Volume 592, Issue 1-4 // July 15 2004, ISSN 0370-2693 page 263. // Inputs: // Double_t temp The temperature at which the current is wanted // Double_t revBiasCurT1 The reference bias current at temp T1 // Double_t tempT1 The temperature correstponding to revBiasCurT1 // Double_t energy=1.2 Some energy [eV] // Output: // none. // Return: // The reverse bias current at the tempeature temp. const Double_t kBoltz = 8.617343E-5; //[eV/K] return revBiasCurT1*(temp*temp/(tempT1*tempT1))* TMath::Exp(-0.5*energy*(tempT1-temp)/(kBoltz*tempT1*temp)); } //---------------------------------------------------------------------- void AliITSCalibration::Print(ostream *os) const { // Standard output format for this class. // Inputs: *os << fdv << " " << fN << " " << fT << " "; *os << fGeVcharge; // printf("%-10.6e %-10.6e %-10.6e %-10.6e \n",fdv,fN,fT,fGeVcharge); return; } //---------------------------------------------------------------------- void AliITSCalibration::Read(istream *is) { // Standard input format for this class. // Inputs: // ostream *is Pointer to the output stream // Outputs: // none: // Return: // none. *is >> fdv >> fN >> fT >> fGeVcharge; return; } //---------------------------------------------------------------------- ostream &operator<<(ostream &os,AliITSCalibration &p){ // Standard output streaming function. // Inputs: // ostream *os Pointer to the output stream // Outputs: // none: // Return: // none. p.Print(&os); return os; } //---------------------------------------------------------------------- istream &operator>>(istream &is,AliITSCalibration &r){ // Standard input streaming function. // Inputs: // ostream *os Pointer to the output stream // Outputs: // none: // Return: // none. r.Read(&is); return is; } //----------------------------------------------------------------------