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4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
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14 **************************************************************************/
18 ///////////////////////////////////////////////////////////////////
20 // Implementation of the class to store the parameters used in //
21 // the simulation of SPD, SDD and SSD detectors //
22 // Origin: F.Prino, Torino, prino@to.infn.it //
24 ///////////////////////////////////////////////////////////////////
26 #include "AliITSSimuParam.h"
29 const Float_t AliITSSimuParam::fgkSPDBiasVoltageDefault = 18.182;
30 const Double_t AliITSSimuParam::fgkSPDThreshDefault = 3000.;
31 const Double_t AliITSSimuParam::fgkSPDSigmaDefault = 250.;
32 const TString AliITSSimuParam::fgkSPDCouplingOptDefault = "old";
33 const Double_t AliITSSimuParam::fgkSPDCouplColDefault = 0.;
34 const Double_t AliITSSimuParam::fgkSPDCouplRowDefault = 0.055;
35 const Float_t AliITSSimuParam::fgkSPDEccDiffDefault = 0.85;
36 const Float_t AliITSSimuParam::fgkSDDDiffCoeffDefault = 3.23;
37 const Float_t AliITSSimuParam::fgkSDDDiffCoeff1Default = 30.;
38 const Float_t AliITSSimuParam::fgkSDDJitterErrorDefault = 20.; // 20 um from beam test 2001
39 const Float_t AliITSSimuParam::fgkSDDDynamicRangeDefault = 1400./2.5; // mV/MOhm = nA
40 const Int_t AliITSSimuParam::fgkSDDMaxAdcDefault = 1024;
41 const Float_t AliITSSimuParam::fgkSDDChargeLossDefault = 0.;
42 const Double_t AliITSSimuParam::fgkSSDCouplingPRDefault = 0.01;
43 const Double_t AliITSSimuParam::fgkSSDCouplingPLDefault = 0.01;
44 const Double_t AliITSSimuParam::fgkSSDCouplingNRDefault = 0.01;
45 const Double_t AliITSSimuParam::fgkSSDCouplingNLDefault = 0.01;
46 const Int_t AliITSSimuParam::fgkSSDZSThresholdDefault = 3;
48 const Float_t AliITSSimuParam::fgkNsigmasDefault = 3.;
49 const Int_t AliITSSimuParam::fgkNcompsDefault = 121;
51 ClassImp(AliITSSimuParam)
53 //______________________________________________________________________
54 AliITSSimuParam::AliITSSimuParam():
58 //fSPDBiasVoltage(fgkSPDBiasVoltageDefault),
59 //fSPDThresh(fgkSPDThreshDefault),
60 //fSPDSigma(fgkSPDSigmaDefault),
62 fSPDCouplCol(fgkSPDCouplColDefault),
63 fSPDCouplRow(fgkSPDCouplRowDefault),
68 fSDDJitterError(fgkSDDJitterErrorDefault),
69 fSDDDynamicRange(fgkSDDDynamicRangeDefault),
71 fSDDChargeLoss(fgkSDDChargeLossDefault),
76 fSSDZSThreshold(fgkSSDZSThresholdDefault),
77 fNsigmas(fgkNsigmasDefault),
78 fNcomps(fgkNcompsDefault),
83 // default constructor
84 SetSPDBiasVoltageAll(fgkSPDBiasVoltageDefault);
85 SetSPDThresholdsAll(fgkSPDThreshDefault,fgkSPDSigmaDefault);
88 SetDistanceOverVoltage();
89 SetSPDCouplingOption(fgkSPDCouplingOptDefault);
90 SetSPDSigmaDiffusionAsymmetry(fgkSPDEccDiffDefault);
92 SetSDDDiffCoeff(fgkSDDDiffCoeffDefault,fgkSDDDiffCoeff1Default);
93 SetSDDMaxAdc((Double_t)fgkSDDMaxAdcDefault);
94 SetSSDCouplings(fgkSSDCouplingPRDefault,fgkSSDCouplingPLDefault,fgkSSDCouplingNRDefault,fgkSSDCouplingNLDefault);
96 //______________________________________________________________________
97 AliITSSimuParam::AliITSSimuParam(const AliITSSimuParam &simpar):
99 fGeVcharge(simpar.fGeVcharge),
100 fDOverV(simpar.fDOverV),
101 //fSPDBiasVoltage(simpar.fSPDBiasVoltage),
102 //fSPDThresh(simpar.fSPDThresh),
103 //fSPDSigma(simpar.fSPDSigma),
104 fSPDCouplOpt(simpar.fSPDCouplOpt),
105 fSPDCouplCol(simpar.fSPDCouplCol),
106 fSPDCouplRow(simpar.fSPDCouplRow),
107 fSPDEccDiff(simpar.fSPDEccDiff),
108 fSDDElectronics(simpar.fSDDElectronics),
109 fSDDDiffCoeff(simpar.fSDDDiffCoeff),
110 fSDDDiffCoeff1(simpar.fSDDDiffCoeff1),
111 fSDDJitterError(simpar.fSDDJitterError),
112 fSDDDynamicRange(simpar.fSDDDynamicRange),
113 fSDDMaxAdc(simpar.fSDDMaxAdc),
114 fSDDChargeLoss(simpar.fSDDChargeLoss),
115 fSSDCouplingPR(simpar.fSSDCouplingPR),
116 fSSDCouplingPL(simpar.fSSDCouplingPL),
117 fSSDCouplingNR(simpar.fSSDCouplingNR),
118 fSSDCouplingNL(simpar.fSSDCouplingNL),
119 fSSDZSThreshold(simpar.fSSDZSThreshold),
120 fNsigmas(simpar.fNsigmas),
121 fNcomps(simpar.fNcomps),
126 for (Int_t i=0;i<240;i++) {
127 fSPDBiasVoltage[i]=simpar.fSPDBiasVoltage[i];
128 fSPDThresh[i]=simpar.fSPDThresh[i];
129 fSPDSigma[i]=simpar.fSPDSigma[i];
130 fSPDNoise[i]=simpar.fSPDNoise[i];
131 fSPDBaseline[i]=simpar.fSPDBaseline[i];
135 //______________________________________________________________________
136 AliITSSimuParam& AliITSSimuParam::operator=(const AliITSSimuParam& source){
137 // Assignment operator.
138 this->~AliITSSimuParam();
139 new(this) AliITSSimuParam(source);
145 //______________________________________________________________________
146 AliITSSimuParam::~AliITSSimuParam() {
148 if(fGaus) delete fGaus;
150 //________________________________________________________________________
151 void AliITSSimuParam::SetNLookUp(Int_t p1){
152 // Set number of sigmas over which cluster disintegration is performed
154 if (fGaus) delete fGaus;
155 fGaus = new TArrayF(fNcomps+1);
156 for(Int_t i=0; i<=fNcomps; i++) {
157 Float_t x = -fNsigmas + (2.*i*fNsigmas)/(fNcomps-1);
158 (*fGaus)[i] = exp(-((x*x)/2));
161 //________________________________________________________________________
162 void AliITSSimuParam::PrintParameters() const{
163 printf("GeVToCharge = %G\n",fGeVcharge);
164 printf("DistanveOverVoltage = %f \n",fDOverV);
166 printf("===== SPD parameters =====\n");
167 printf("Bias Voltage = %f \n",fSPDBiasVoltage[0]);
168 printf("Threshold and sigma = %f %f\n",fSPDThresh[0],fSPDSigma[0]);
169 printf("Coupling Option = %s\n",fSPDCouplOpt.Data());
170 printf("Coupling value (column) = %f\n",fSPDCouplCol);
171 printf("Coupling value (row) = %f\n",fSPDCouplRow);
172 printf("Eccentricity in diffusion = %f\n",fSPDEccDiff);
174 printf("===== SDD parameters =====\n");
175 printf("Electronic chips = %d\n",fSDDElectronics);
176 printf("Diffusion Coefficients = %f %f\n",fSDDDiffCoeff,fSDDDiffCoeff1);
177 printf("Jitter Error = %f um\n",fSDDJitterError);
178 printf("Dynamic Range = %f\n",fSDDDynamicRange);
179 printf("Max. ADC = %f\n",fSDDMaxAdc);
180 printf("Charge Loss = %f\n",fSDDChargeLoss);
182 printf("===== SSD parameters =====\n");
183 printf("Coupling PR = %f\n",fSSDCouplingPR);
184 printf("Coupling PL = %f\n",fSSDCouplingPL);
185 printf("Coupling NR = %f\n",fSSDCouplingNR);
186 printf("Coupling NL = %f\n",fSSDCouplingNL);
187 printf("Zero Supp threshold = %d\n",fSSDZSThreshold);
189 //______________________________________________________________________
190 Double_t AliITSSimuParam::MobilityElectronSiEmp() const {
191 // Computes the electron mobility in cm^2/volt-sec. Taken from SILVACO
192 // International ATLAS II, 2D Device Simulation Framework, User Manual
193 // Chapter 5 Equation 5-6. An empirical function for low-field mobiliity
194 // in silicon at different tempeatures.
200 // The Mobility of electrons in Si at a give temprature and impurity
201 // concentration. [cm^2/Volt-sec]
202 const Double_t km0 = 55.24; // cm^2/Volt-sec
203 const Double_t km1 = 7.12E+08; // cm^2 (degree K)^2.3 / Volt-sec
204 const Double_t kN0 = 1.072E17; // #/cm^3
205 const Double_t kT0 = 300.; // degree K.
206 const Double_t keT0 = -2.3; // Power of Temp.
207 const Double_t keT1 = -3.8; // Power of Temp.
208 const Double_t keN = 0.73; // Power of Dopent Consentrations
210 Double_t tT = fT,nN = fN;
212 if(nN<=0.0){ // Simple case.
213 if(tT==300.) return 1350.0; // From Table 5-1 at consentration 1.0E14.
214 m = km1*TMath::Power(tT,keT0);
217 m = km1*TMath::Power(tT,keT0) - km0;
218 m /= 1.0 + TMath::Power(tT/kT0,keT1)*TMath::Power(nN/kN0,keN);
222 //______________________________________________________________________
223 Double_t AliITSSimuParam::MobilityHoleSiEmp() const {
224 // Computes the Hole mobility in cm^2/volt-sec. Taken from SILVACO
225 // International ATLAS II, 2D Device Simulation Framework, User Manual
226 // Chapter 5 Equation 5-7 An empirical function for low-field mobiliity
227 // in silicon at different tempeatures.
233 // The Mobility of Hole in Si at a give temprature and impurity
234 // concentration. [cm^2/Volt-sec]
235 const Double_t km0a = 49.74; // cm^2/Volt-sec
236 const Double_t km0b = 49.70; // cm^2/Volt-sec
237 const Double_t km1 = 1.35E+08; // cm^2 (degree K)^2.3 / Volt-sec
238 const Double_t kN0 = 1.606E17; // #/cm^3
239 const Double_t kT0 = 300.; // degree K.
240 const Double_t keT0 = -2.2; // Power of Temp.
241 const Double_t keT1 = -3.7; // Power of Temp.
242 const Double_t keN = 0.70; // Power of Dopent Consentrations
244 Double_t tT = fT,nN = fN;
246 if(nN<=0.0){ // Simple case.
247 if(tT==300.) return 495.0; // From Table 5-1 at consentration 1.0E14.
248 m = km1*TMath::Power(tT,keT0) + km0a-km0b;
251 m = km1*TMath::Power(tT,keT0) - km0b;
252 m /= 1.0 + TMath::Power(tT/kT0,keT1)*TMath::Power(nN/kN0,keN);
256 //______________________________________________________________________
257 Double_t AliITSSimuParam::DiffusionCoefficientElectron() const {
258 // Computes the Diffusion coefficient for electrons in cm^2/sec. Taken
259 // from SILVACO International ATLAS II, 2D Device Simulation Framework,
260 // User Manual Chapter 5 Equation 5-53. Einstein relations for diffusion
261 // coefficient. Note: 1 cm^2/sec = 10 microns^2/nanosec.
267 // The Diffusion Coefficient of electrons in Si at a give temprature
268 // and impurity concentration. [cm^2/sec]
269 // const Double_t kb = 1.3806503E-23; // Joules/degree K
270 // const Double_t qe = 1.60217646E-19; // Coulumbs.
271 const Double_t kbqe = 8.617342312E-5; // Volt/degree K
272 Double_t m = MobilityElectronSiEmp();
275 return m*kbqe*tT; // [cm^2/sec]
277 //______________________________________________________________________
278 Double_t AliITSSimuParam::DiffusionCoefficientHole() const {
279 // Computes the Diffusion coefficient for Holes in cm^2/sec. Taken
280 // from SILVACO International ATLAS II, 2D Device Simulation Framework,
281 // User Manual Chapter 5 Equation 5-53. Einstein relations for diffusion
282 // coefficient. Note: 1 cm^2/sec = 10 microns^2/nanosec.
288 // The Defusion Coefficient of Hole in Si at a give temprature and
289 // impurity concentration. [cm^2/sec]
290 // and impurity concentration. [cm^2/sec]
291 // const Double_t kb = 1.3806503E-23; // Joules/degree K
292 // const Double_t qe = 1.60217646E-19; // Coulumbs.
293 const Double_t kbqe = 8.617342312E-5; // Volt/degree K
294 Double_t m = MobilityHoleSiEmp();
297 return m*kbqe*tT; // [cm^2/sec]
299 //______________________________________________________________________
300 Double_t AliITSSimuParam::LorentzAngleHole(Double_t B) const {
301 // Computes the Lorentz angle for electrons in Si
302 // Input: magnetic Field in KGauss
303 // Output: Lorentz angle in radians (positive if Bz is positive)
304 // Main Reference: NIM A 497 (2003) 389–396.
305 // "An algorithm for calculating the Lorentz angle in silicon detectors", V. Bartsch et al.
307 const Double_t krH=0.70; // Hall scattering factor for Hole
308 const Double_t kT0 = 300.; // reference Temperature (degree K).
309 const Double_t kmulow0 = 470.5; // cm^2/Volt-sec
310 const Double_t keT0 = -2.5; // Power of Temp.
311 const Double_t beta0 = 1.213; // beta coeff. at T0=300K
312 const Double_t keT1 = 0.17; // Power of Temp. for beta
313 const Double_t kvsat0 = 8.37E+06; // saturated velocity at T0=300K (cm/sec)
314 const Double_t keT2 = 0.52; // Power of Temp. for vsat
316 Double_t eE= 1./fDOverV;
317 Double_t muLow=kmulow0*TMath::Power(tT/kT0,keT0);
318 Double_t beta=beta0*TMath::Power(tT/kT0,keT1);
319 Double_t vsat=kvsat0*TMath::Power(tT/kT0,keT2);
320 Double_t mu=muLow/TMath::Power(1+TMath::Power(muLow*eE/vsat,beta),1/beta);
321 Double_t angle=TMath::ATan(krH*mu*B*1.E-05); // Conversion Factor
324 //______________________________________________________________________
325 Double_t AliITSSimuParam::LorentzAngleElectron(Double_t B) const {
326 // Computes the Lorentz angle for electrons in Si
327 // Input: magnetic Field in KGauss
328 // Output: Lorentz angle in radians (positive if Bz is positive)
329 // Main Reference: NIM A 497 (2003) 389–396.
330 // "An algorithm for calculating the Lorentz angle in silicon detectors", V. Bartsch et al.
332 const Double_t krH=1.15; // Hall scattering factor for Electron
333 const Double_t kT0 = 300.; // reference Temperature (degree K).
334 const Double_t kmulow0 = 1417.0; // cm^2/Volt-sec
335 const Double_t keT0 = -2.2; // Power of Temp.
336 const Double_t beta0 = 1.109; // beta coeff. at T0=300K
337 const Double_t keT1 = 0.66; // Power of Temp. for beta
338 const Double_t kvsat0 = 1.07E+07; // saturated velocity at T0=300K (cm/sec)
339 const Double_t keT2 = 0.87; // Power of Temp. for vsat
341 Double_t eE= 1./fDOverV;
342 Double_t muLow=kmulow0*TMath::Power(tT/kT0,keT0);
343 Double_t beta=beta0*TMath::Power(tT/kT0,keT1);
344 Double_t vsat=kvsat0*TMath::Power(tT/kT0,keT2);
345 Double_t mu=muLow/TMath::Power(1+TMath::Power(muLow*eE/vsat,beta),1/beta);
346 Double_t angle=TMath::ATan(krH*mu*B*1.E-05);
349 //______________________________________________________________________
350 Double_t AliITSSimuParam::SpeedElectron() const {
351 // Computes the average speed for electrons in Si under the low-field
352 // approximation. [cm/sec].
358 // The speed the holes are traveling at due to the low field applied.
360 Double_t m = MobilityElectronSiEmp();
362 return m/fDOverV; // [cm/sec]
364 //______________________________________________________________________
365 Double_t AliITSSimuParam::SpeedHole() const {
366 // Computes the average speed for Holes in Si under the low-field
367 // approximation.[cm/sec].
373 // The speed the holes are traveling at due to the low field applied.
375 Double_t m = MobilityHoleSiEmp();
377 return m/fDOverV; // [cm/sec]
379 //______________________________________________________________________
380 Double_t AliITSSimuParam::SigmaDiffusion3D(Double_t l) const {
381 // Returns the Gaussian sigma^2 == <x^2+y^2+z^2> [cm^2] due to the
382 // defusion of electrons or holes through a distance l [cm] caused
383 // by an applied voltage v [volt] through a distance d [cm] in any
384 // material at a temperature T [degree K]. The sigma diffusion when
385 // expressed in terms of the distance over which the diffusion
386 // occures, l=time/speed, is independent of the mobility and therefore
387 // the properties of the material. The charge distributions is given by
388 // n = exp(-r^2/4Dt)/(4piDt)^1.5. From this <r^2> = 6Dt where D=mkT/e
389 // (m==mobility, k==Boltzman's constant, T==temparature, e==electric
390 // charge. and vel=m*v/d. consiquently sigma^2=6kTdl/ev.
392 // Double_t l Distance the charge has to travel.
396 // The Sigma due to the diffution of electrons. [cm]
397 const Double_t kcon = 5.17040258E-04; // == 6k/e [J/col or volts]
399 return TMath::Sqrt(kcon*fT*fDOverV*l); // [cm]
401 //______________________________________________________________________
402 Double_t AliITSSimuParam::SigmaDiffusion2D(Double_t l) const {
403 // Returns the Gaussian sigma^2 == <x^2+z^2> [cm^2] due to the defusion
404 // of electrons or holes through a distance l [cm] caused by an applied
405 // voltage v [volt] through a distance d [cm] in any material at a
406 // temperature T [degree K]. The sigma diffusion when expressed in terms
407 // of the distance over which the diffusion occures, l=time/speed, is
408 // independent of the mobility and therefore the properties of the
409 // material. The charge distributions is given by
410 // n = exp(-r^2/4Dt)/(4piDt)^1.5. From this <x^2+z^2> = 4Dt where D=mkT/e
411 // (m==mobility, k==Boltzman's constant, T==temparature, e==electric
412 // charge. and vel=m*v/d. consiquently sigma^2=4kTdl/ev.
414 // Double_t l Distance the charge has to travel.
418 // The Sigma due to the diffution of electrons. [cm]
419 const Double_t kcon = 3.446935053E-04; // == 4k/e [J/col or volts]
421 return TMath::Sqrt(kcon*fT*fDOverV*l); // [cm]
423 //______________________________________________________________________
424 Double_t AliITSSimuParam::SigmaDiffusion1D(Double_t l) const {
425 // Returns the Gaussian sigma^2 == <x^2> [cm^2] due to the defusion
426 // of electrons or holes through a distance l [cm] caused by an applied
427 // voltage v [volt] through a distance d [cm] in any material at a
428 // temperature T [degree K]. The sigma diffusion when expressed in terms
429 // of the distance over which the diffusion occures, l=time/speed, is
430 // independent of the mobility and therefore the properties of the
431 // material. The charge distributions is given by
432 // n = exp(-r^2/4Dt)/(4piDt)^1.5. From this <r^2> = 2Dt where D=mkT/e
433 // (m==mobility, k==Boltzman's constant, T==temparature, e==electric
434 // charge. and vel=m*v/d. consiquently sigma^2=2kTdl/ev.
436 // Double_t l Distance the charge has to travel.
440 // The Sigma due to the diffution of electrons. [cm]
441 const Double_t kcon = 1.723467527E-04; // == 2k/e [J/col or volts]
443 return TMath::Sqrt(kcon*fT*fDOverV*l); // [cm]
445 //----------------------------------------------------------------------
446 Double_t AliITSSimuParam::DepletedRegionThicknessA(Double_t dopCons,
449 Double_t voltBuiltIn)const{
450 // Computes the thickness of the depleted region in Si due to the
451 // application of an external bias voltage. From the Particle Data
452 // Book, 28.8 Silicon semiconductor detectors equation 28.19 (2004)
453 // Physics Letters B "Review of Particle Physics" Volume 592, Issue 1-4
454 // July 15 2004, ISSN 0370-2693 page 263. First equation.
456 // Double_t dopCons "N" doping concentration
457 // Double_t voltage "V" external bias voltage
458 // Double_t elecCharge "e" electronic charge
459 // Double_t voltBuiltIn=0.5 "V_bi" "built-in" Voltage (~0.5V for
460 // resistivities typically used in detectors)
464 // The thickness of the depleted region
466 return TMath::Sqrt(2.0*(voltage+voltBuiltIn)/(dopCons*elecCharge));
468 //----------------------------------------------------------------------
469 Double_t AliITSSimuParam::DepletedRegionThicknessB(Double_t resist,
472 Double_t voltBuiltIn,
473 Double_t dielConst)const{
474 // Computes the thickness of the depleted region in Si due to the
475 // application of an external bias voltage. From the Particle Data
476 // Book, 28.8 Silicon semiconductor detectors equation 28.19 (2004)
477 // Physics Letters B "Review of Particle Physics" Volume 592, Issue 1-4
478 // July 15 2004, ISSN 0370-2693 page 263. Second Equation.
480 // Double_t resist "rho" resistivity (typically 1-10 kOhm cm)
481 // Double_t voltage "V" external bias voltage
482 // Double_t mobility "mu" charge carrier mobility
483 // (electons 1350, holes 450 cm^2/V/s)
484 // Double_t voltBuiltIn=0.5 "V_bi" "built-in" Voltage (~0.5V for
485 // resistivities typically used in detectors)
486 // Double_t dielConst=1.E-12 "epsilon" dielectric constant = 11.9 *
487 // (permittivity of free space) or ~ 1 pF/cm
491 // The thickness of the depleted region
493 return TMath::Sqrt(2.8*resist*mobility*dielConst*(voltage+voltBuiltIn));
495 //----------------------------------------------------------------------
496 Double_t AliITSSimuParam::ReverseBiasCurrent(Double_t temp,
497 Double_t revBiasCurT1,
499 Double_t energy)const{
500 // Computes the temperature dependance of the reverse bias current
501 // of Si detectors. From the Particle Data
502 // Book, 28.8 Silicon semiconductor detectors equation 28.21 (2004)
503 // Physics Letters B "Review of Particle Physics" Volume 592, Issue 1-4
504 // July 15 2004, ISSN 0370-2693 page 263.
506 // Double_t temp The temperature at which the current is wanted
507 // Double_t revBiasCurT1 The reference bias current at temp T1
508 // Double_t tempT1 The temperature correstponding to revBiasCurT1
509 // Double_t energy=1.2 Some energy [eV]
513 // The reverse bias current at the tempeature temp.
514 const Double_t kBoltz = 8.617343E-5; //[eV/K]
516 return revBiasCurT1*(temp*temp/(tempT1*tempT1))*
517 TMath::Exp(-0.5*energy*(tempT1-temp)/(kBoltz*tempT1*temp));
519 //______________________________________________________________________
520 void AliITSSimuParam::SPDThresholds(const Int_t mod, Double_t& thresh, Double_t& sigma) const {
521 if(mod<0 || mod>239) {
526 thresh=fSPDThresh[mod];
527 sigma=fSPDSigma[mod];
530 //_______________________________________________________________________
531 void AliITSSimuParam::SPDNoise(const Int_t mod,Double_t &noise, Double_t &baseline) const {
532 if(mod<0 || mod>239) {
537 noise=fSPDNoise[mod];
538 baseline=fSPDBaseline[mod];