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1 | /************************************************************************** | |
2 | * Copyright(c) 2007-2009, ALICE Experiment at CERN, All rights reserved. * | |
3 | * * | |
4 | * Author: The ALICE Off-line Project. * | |
5 | * Contributors are mentioned in the code where appropriate. * | |
6 | * * | |
7 | * Permission to use, copy, modify and distribute this software and its * | |
8 | * documentation strictly for non-commercial purposes is hereby granted * | |
9 | * without fee, provided that the above copyright notice appears in all * | |
10 | * copies and that both the copyright notice and this permission notice * | |
11 | * appear in the supporting documentation. The authors make no claims * | |
12 | * about the suitability of this software for any purpose. It is * | |
13 | * provided "as is" without express or implied warranty. * | |
14 | **************************************************************************/ | |
15 | ||
16 | /* $Id$ */ | |
17 | ||
18 | /////////////////////////////////////////////////////////////////// | |
19 | // // | |
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 // | |
23 | // // | |
24 | /////////////////////////////////////////////////////////////////// | |
25 | ||
26 | #include "AliITSSimuParam.h" | |
27 | #include <TMath.h> | |
28 | ||
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; | |
47 | ||
48 | const Float_t AliITSSimuParam::fgkNsigmasDefault = 3.; | |
49 | const Int_t AliITSSimuParam::fgkNcompsDefault = 121; | |
50 | ||
51 | ClassImp(AliITSSimuParam) | |
52 | ||
53 | //______________________________________________________________________ | |
54 | AliITSSimuParam::AliITSSimuParam(): | |
55 | TObject(), | |
56 | fGeVcharge(0.), | |
57 | fDOverV(0.), | |
58 | //fSPDBiasVoltage(fgkSPDBiasVoltageDefault), | |
59 | //fSPDThresh(fgkSPDThreshDefault), | |
60 | //fSPDSigma(fgkSPDSigmaDefault), | |
61 | fSPDCouplOpt(0), | |
62 | fSPDCouplCol(fgkSPDCouplColDefault), | |
63 | fSPDCouplRow(fgkSPDCouplRowDefault), | |
64 | fSPDEccDiff(0.), | |
65 | fSDDElectronics(0), | |
66 | fSDDDiffCoeff(0.), | |
67 | fSDDDiffCoeff1(0.), | |
68 | fSDDJitterError(fgkSDDJitterErrorDefault), | |
69 | fSDDDynamicRange(fgkSDDDynamicRangeDefault), | |
70 | fSDDMaxAdc(0.), | |
71 | fSDDChargeLoss(fgkSDDChargeLossDefault), | |
72 | fSSDCouplingPR(0), | |
73 | fSSDCouplingPL(0), | |
74 | fSSDCouplingNR(0), | |
75 | fSSDCouplingNL(0), | |
76 | fSSDZSThreshold(fgkSSDZSThresholdDefault), | |
77 | fNsigmas(fgkNsigmasDefault), | |
78 | fNcomps(fgkNcompsDefault), | |
79 | fGaus(), | |
80 | fN(0.), | |
81 | fT(300.) | |
82 | { | |
83 | // default constructor | |
84 | SetSPDBiasVoltageAll(fgkSPDBiasVoltageDefault); | |
85 | SetSPDThresholdsAll(fgkSPDThreshDefault,fgkSPDSigmaDefault); | |
86 | SetSPDNoiseAll(0,0); | |
87 | SetGeVToCharge(); | |
88 | SetDistanceOverVoltage(); | |
89 | SetSPDCouplingOption(fgkSPDCouplingOptDefault); | |
90 | SetSPDSigmaDiffusionAsymmetry(fgkSPDEccDiffDefault); | |
91 | SetSDDElectronics(); | |
92 | SetSDDDiffCoeff(fgkSDDDiffCoeffDefault,fgkSDDDiffCoeff1Default); | |
93 | SetSDDMaxAdc((Double_t)fgkSDDMaxAdcDefault); | |
94 | SetSSDCouplings(fgkSSDCouplingPRDefault,fgkSSDCouplingPLDefault,fgkSSDCouplingNRDefault,fgkSSDCouplingNLDefault); | |
95 | } | |
96 | //______________________________________________________________________ | |
97 | AliITSSimuParam::AliITSSimuParam(const AliITSSimuParam &simpar): | |
98 | TObject(), | |
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), | |
122 | fGaus(), | |
123 | fN(simpar.fN), | |
124 | fT(simpar.fT){ | |
125 | // copy constructor | |
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]; | |
132 | } | |
133 | } | |
134 | ||
135 | //______________________________________________________________________ | |
136 | AliITSSimuParam& AliITSSimuParam::operator=(const AliITSSimuParam& source){ | |
137 | // Assignment operator. | |
138 | this->~AliITSSimuParam(); | |
139 | new(this) AliITSSimuParam(source); | |
140 | return *this; | |
141 | ||
142 | } | |
143 | ||
144 | ||
145 | //______________________________________________________________________ | |
146 | AliITSSimuParam::~AliITSSimuParam() { | |
147 | // destructor | |
148 | if(fGaus) delete fGaus; | |
149 | } | |
150 | //________________________________________________________________________ | |
151 | void AliITSSimuParam::SetNLookUp(Int_t p1){ | |
152 | // Set number of sigmas over which cluster disintegration is performed | |
153 | fNcomps=p1; | |
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)); | |
159 | } | |
160 | } | |
161 | //________________________________________________________________________ | |
162 | void AliITSSimuParam::PrintParameters() const{ | |
163 | printf("GeVToCharge = %G\n",fGeVcharge); | |
164 | printf("DistanveOverVoltage = %f \n",fDOverV); | |
165 | printf("\n"); | |
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); | |
173 | printf("\n"); | |
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); | |
181 | printf("\n"); | |
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); | |
188 | } | |
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. | |
195 | // Inputs: | |
196 | // none. | |
197 | // Output: | |
198 | // none. | |
199 | // Return: | |
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 | |
209 | Double_t m; | |
210 | Double_t tT = fT,nN = fN; | |
211 | ||
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); | |
215 | return m; | |
216 | } // if nN<=0.0 | |
217 | m = km1*TMath::Power(tT,keT0) - km0; | |
218 | m /= 1.0 + TMath::Power(tT/kT0,keT1)*TMath::Power(nN/kN0,keN); | |
219 | m += km0; | |
220 | return m; | |
221 | } | |
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. | |
228 | // Inputs: | |
229 | // none. | |
230 | // Output: | |
231 | // none. | |
232 | // Return: | |
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 | |
243 | Double_t m; | |
244 | Double_t tT = fT,nN = fN; | |
245 | ||
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; | |
249 | return m; | |
250 | } // if nN<=0.0 | |
251 | m = km1*TMath::Power(tT,keT0) - km0b; | |
252 | m /= 1.0 + TMath::Power(tT/kT0,keT1)*TMath::Power(nN/kN0,keN); | |
253 | m += km0a; | |
254 | return m; | |
255 | } | |
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. | |
262 | // Inputs: | |
263 | // none. | |
264 | // Output: | |
265 | // none. | |
266 | // Return: | |
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(); | |
273 | Double_t tT = fT; | |
274 | ||
275 | return m*kbqe*tT; // [cm^2/sec] | |
276 | } | |
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. | |
283 | // Inputs: | |
284 | // none. | |
285 | // Output: | |
286 | // none. | |
287 | // Return: | |
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(); | |
295 | Double_t tT = fT; | |
296 | ||
297 | return m*kbqe*tT; // [cm^2/sec] | |
298 | } | |
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. | |
306 | // | |
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 | |
315 | Double_t tT = fT; | |
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 | |
322 | return angle; | |
323 | } | |
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. | |
331 | // | |
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 | |
340 | Double_t tT = fT; | |
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); | |
347 | return angle; | |
348 | } | |
349 | //______________________________________________________________________ | |
350 | Double_t AliITSSimuParam::SpeedElectron() const { | |
351 | // Computes the average speed for electrons in Si under the low-field | |
352 | // approximation. [cm/sec]. | |
353 | // Inputs: | |
354 | // none. | |
355 | // Output: | |
356 | // none. | |
357 | // Return: | |
358 | // The speed the holes are traveling at due to the low field applied. | |
359 | // [cm/sec] | |
360 | Double_t m = MobilityElectronSiEmp(); | |
361 | ||
362 | return m/fDOverV; // [cm/sec] | |
363 | } | |
364 | //______________________________________________________________________ | |
365 | Double_t AliITSSimuParam::SpeedHole() const { | |
366 | // Computes the average speed for Holes in Si under the low-field | |
367 | // approximation.[cm/sec]. | |
368 | // Inputs: | |
369 | // none. | |
370 | // Output: | |
371 | // none. | |
372 | // Return: | |
373 | // The speed the holes are traveling at due to the low field applied. | |
374 | // [cm/sec] | |
375 | Double_t m = MobilityHoleSiEmp(); | |
376 | ||
377 | return m/fDOverV; // [cm/sec] | |
378 | } | |
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. | |
391 | // Inputs: | |
392 | // Double_t l Distance the charge has to travel. | |
393 | // Output: | |
394 | // none. | |
395 | // Return: | |
396 | // The Sigma due to the diffution of electrons. [cm] | |
397 | const Double_t kcon = 5.17040258E-04; // == 6k/e [J/col or volts] | |
398 | ||
399 | return TMath::Sqrt(kcon*fT*fDOverV*l); // [cm] | |
400 | } | |
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. | |
413 | // Inputs: | |
414 | // Double_t l Distance the charge has to travel. | |
415 | // Output: | |
416 | // none. | |
417 | // Return: | |
418 | // The Sigma due to the diffution of electrons. [cm] | |
419 | const Double_t kcon = 3.446935053E-04; // == 4k/e [J/col or volts] | |
420 | ||
421 | return TMath::Sqrt(kcon*fT*fDOverV*l); // [cm] | |
422 | } | |
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. | |
435 | // Inputs: | |
436 | // Double_t l Distance the charge has to travel. | |
437 | // Output: | |
438 | // none. | |
439 | // Return: | |
440 | // The Sigma due to the diffution of electrons. [cm] | |
441 | const Double_t kcon = 1.723467527E-04; // == 2k/e [J/col or volts] | |
442 | ||
443 | return TMath::Sqrt(kcon*fT*fDOverV*l); // [cm] | |
444 | } | |
445 | //---------------------------------------------------------------------- | |
446 | Double_t AliITSSimuParam::DepletedRegionThicknessA(Double_t dopCons, | |
447 | Double_t voltage, | |
448 | Double_t elecCharge, | |
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. | |
455 | // Inputs: | |
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) | |
461 | // Output: | |
462 | // none. | |
463 | // Return: | |
464 | // The thickness of the depleted region | |
465 | ||
466 | return TMath::Sqrt(2.0*(voltage+voltBuiltIn)/(dopCons*elecCharge)); | |
467 | } | |
468 | //---------------------------------------------------------------------- | |
469 | Double_t AliITSSimuParam::DepletedRegionThicknessB(Double_t resist, | |
470 | Double_t voltage, | |
471 | Double_t mobility, | |
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. | |
479 | // Inputs: | |
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 | |
488 | // Output: | |
489 | // none. | |
490 | // Return: | |
491 | // The thickness of the depleted region | |
492 | ||
493 | return TMath::Sqrt(2.8*resist*mobility*dielConst*(voltage+voltBuiltIn)); | |
494 | } | |
495 | //---------------------------------------------------------------------- | |
496 | Double_t AliITSSimuParam::ReverseBiasCurrent(Double_t temp, | |
497 | Double_t revBiasCurT1, | |
498 | Double_t tempT1, | |
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. | |
505 | // Inputs: | |
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] | |
510 | // Output: | |
511 | // none. | |
512 | // Return: | |
513 | // The reverse bias current at the tempeature temp. | |
514 | const Double_t kBoltz = 8.617343E-5; //[eV/K] | |
515 | ||
516 | return revBiasCurT1*(temp*temp/(tempT1*tempT1))* | |
517 | TMath::Exp(-0.5*energy*(tempT1-temp)/(kBoltz*tempT1*temp)); | |
518 | } | |
519 | //______________________________________________________________________ | |
520 | void AliITSSimuParam::SPDThresholds(const Int_t mod, Double_t& thresh, Double_t& sigma) const { | |
521 | if(mod<0 || mod>239) { | |
522 | thresh=0; | |
523 | sigma=0; | |
524 | return; | |
525 | } | |
526 | thresh=fSPDThresh[mod]; | |
527 | sigma=fSPDSigma[mod]; | |
528 | return; | |
529 | } | |
530 | //_______________________________________________________________________ | |
531 | void AliITSSimuParam::SPDNoise(const Int_t mod,Double_t &noise, Double_t &baseline) const { | |
532 | if(mod<0 || mod>239) { | |
533 | noise=0; | |
534 | baseline=0; | |
535 | return; | |
536 | } | |
537 | noise=fSPDNoise[mod]; | |
538 | baseline=fSPDBaseline[mod]; | |
539 | return; | |
540 | } | |
541 |