From 0c6e05566cce2375ee762d1b121d27acc93653ce Mon Sep 17 00:00:00 2001 From: nilsen Date: Wed, 8 Dec 2004 14:30:19 +0000 Subject: [PATCH] Added 3 new methods regarding Si detectors from the Particle data book. --- ITS/AliITSresponse.cxx | 74 ++++++++++++++++++++++++++++++++++++++++++ ITS/AliITSresponse.h | 19 +++++++++-- 2 files changed, 90 insertions(+), 3 deletions(-) diff --git a/ITS/AliITSresponse.cxx b/ITS/AliITSresponse.cxx index 19f2470988f..22290f9287f 100644 --- a/ITS/AliITSresponse.cxx +++ b/ITS/AliITSresponse.cxx @@ -255,6 +255,80 @@ Double_t AliITSresponse::SigmaDiffusion1D(Double_t l) const { return TMath::Sqrt(kcon*fT*fdv*l); // [cm] } //---------------------------------------------------------------------- +Double_t AliITSresponse::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 AliITSresponse::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+voltBoultIn)); +} +//---------------------------------------------------------------------- +Double_t AliITSresponse::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 kBoltz = 8.617343E-5; //[eV/K] + + return revBiasCurT1*(temp*temp/(tempT1*tempT1))* + TMath::Exp(-0.5*energy*(tempT1-temp)/(kBoltz*tempT1*temp)); +} +//---------------------------------------------------------------------- void AliITSresponse::Print(ostream *os) const { // Standard output format for this class. // Inputs: diff --git a/ITS/AliITSresponse.h b/ITS/AliITSresponse.h index 862d65d10fe..2f37c4cea06 100644 --- a/ITS/AliITSresponse.h +++ b/ITS/AliITSresponse.h @@ -143,17 +143,30 @@ class AliITSresponse : public TObject { // 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]. - virtual Double_t SigmaDiffusion3D(Double_t l) const ; + virtual Double_t SigmaDiffusion3D(Double_t l) const; // Returns the Gaussian sigma == [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]. - virtual Double_t SigmaDiffusion2D(Double_t l) const ; + virtual Double_t SigmaDiffusion2D(Double_t l) const; // Returns the Gaussian sigma == [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]. - virtual Double_t SigmaDiffusion1D(Double_t l) const ; + virtual Double_t SigmaDiffusion1D(Double_t l) const; + // Compute the thickness of the depleted region in a Si detector, version A + virtual Double_t DepletedRegionThicknessA(Double_t dopCons, + Double_t voltage, + Double_t elecCharge, + Double_t voltBuiltIn=0.5)const; + // Compute the thickness of the depleted region in a Si detector, version B + virtual Double_t DepletedRegionThicknessB(Double_t resist,Double_t voltage, + Double_t mobility, + Double_t voltBuiltIn=0.5, + Double_t dielConst=1.E-12)const; + // Computes the temperature dependance of the reverse bias current + virtual Double_t ReverseBiasCurrent(Double_t temp,Double_t revBiasCurT1, + Double_t tempT1,Double_t energy=1.2)const; // Prints out the content of this class in ASCII format. virtual void Print(ostream *os) const; // Reads in the content of this class in the format of Print -- 2.39.3