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1209231c | 1 | /************************************************************************** |
2 | * Copyright(c) 2006-07, 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 | ||
17 | /////////////////////////////////////////////////////////////////////////////// | |
18 | // // | |
19 | // Class describing the Vdrift dependencies on E,T,P and GasComposition // | |
20 | // Authors: Stefan Rossegger, Haavard Helstrup // | |
21 | // // | |
22 | /////////////////////////////////////////////////////////////////////////////// | |
23 | ||
24 | #include "TSystem.h" | |
25 | #include "TObject.h" | |
26 | #include "TMath.h" | |
27 | #include "AliTPCTempMap.h" | |
28 | #include "AliTPCSensorTempArray.h" | |
29 | ||
30 | #include "AliTPCCalibVdrift.h" | |
31 | ||
32 | ClassImp(AliTPCCalibVdrift) | |
33 | ||
34 | namespace paramDefinitions { | |
35 | ||
36 | // Standard Conditions used as origin in the Magbolz simulations | |
37 | // Dimesions E [kV/cm], T [K], P [TORR], Cco2 [%], Cn2 [%] | |
38 | const Double_t kstdE = 400; | |
39 | const Double_t kstdT = 293; | |
40 | const Double_t kstdP = 744; | |
41 | const Double_t kstdCco2 = 9.52; | |
42 | const Double_t kstdCn2 = 4.76; | |
43 | // Driftvelocity at Standardcontitions [cm/microSec] | |
44 | const Double_t kstdVdrift = 2.57563; | |
45 | ||
46 | // Vdrift dependencies simulated with Magbolz [%(Vdrift)/[unit]] | |
47 | const Double_t kdvdE = 0.24; | |
48 | const Double_t kdvdT = 0.30; | |
49 | const Double_t kdvdP = -0.13; | |
50 | const Double_t kdvdCco2 = -6.60; | |
51 | const Double_t kdvdCn2 = -1.74; | |
52 | ||
53 | Double_t krho = 0.934246; // density of TPC-Gas [kg/m^3] | |
54 | // method of calculation: weighted average | |
55 | Double_t kg = 9.81; | |
56 | } | |
57 | ||
58 | using namespace paramDefinitions; | |
59 | ||
60 | AliTPCCalibVdrift::AliTPCCalibVdrift(AliTPCSensorTempArray *SensTemp, TObject *SensPres, TObject *SensGasComp): | |
61 | TNamed(), | |
62 | fSensTemp(0), | |
63 | fSensPres(0), | |
64 | fSensGasComp(0) | |
65 | { | |
66 | // | |
67 | // Standard constructor | |
68 | // | |
69 | ||
70 | fSensTemp = SensTemp; | |
71 | fSensPres = SensPres; | |
72 | fSensGasComp = SensGasComp; | |
73 | } | |
74 | ||
75 | AliTPCCalibVdrift::AliTPCCalibVdrift(const AliTPCCalibVdrift& source) : | |
76 | TNamed(source), | |
77 | fSensTemp(source.fSensTemp), | |
78 | fSensPres(source.fSensPres), | |
79 | fSensGasComp(source.fSensGasComp) | |
80 | { | |
81 | // | |
82 | // Copy constructor | |
83 | // | |
84 | } | |
85 | ||
86 | //_____________________________________________________________________________ | |
87 | ||
88 | AliTPCCalibVdrift& AliTPCCalibVdrift::operator=(const AliTPCCalibVdrift& source){ | |
89 | // | |
90 | // assignment operator | |
91 | // | |
92 | if (&source == this) return *this; | |
93 | new (this) AliTPCCalibVdrift(source); | |
94 | ||
95 | return *this; | |
96 | } | |
97 | ||
98 | //_____________________________________________________________________________ | |
99 | AliTPCCalibVdrift::~AliTPCCalibVdrift() | |
100 | { | |
101 | // | |
102 | // AliTPCCalibVdrift destructor | |
103 | // | |
104 | } | |
105 | ||
106 | //_____________________________________________________________________________ | |
107 | Double_t AliTPCCalibVdrift::VdriftLinearHyperplaneApprox(Double_t dE, Double_t dT, Double_t dP, Double_t dCco2, Double_t dCn2) | |
108 | { | |
109 | // | |
110 | // Returns approximated value for the driftvelocity based on | |
111 | // linear Hyperplane approximation (~ Taylorapproximation of 1st order) | |
112 | // | |
113 | ||
2aaa30ef | 114 | Double_t vdrift = (dE*kdvdE+dT*kdvdT+dP*kdvdP+dCco2*kdvdCco2+dCn2*kdvdCn2); |
1209231c | 115 | |
2aaa30ef | 116 | return vdrift; |
1209231c | 117 | |
118 | } | |
119 | //_____________________________________________________________________________ | |
120 | ||
121 | Double_t AliTPCCalibVdrift::GetVdriftNominal() | |
122 | { | |
123 | // returns nominal Driftvelocity at StandardConditions | |
124 | return kstdVdrift; | |
125 | } | |
126 | ||
127 | //_____________________________________________________________________________ | |
128 | ||
129 | Double_t AliTPCCalibVdrift::GetVdriftChange(Double_t x, Double_t y, Double_t z, UInt_t timeSec) | |
130 | { | |
131 | // | |
132 | // Calculates Vdrift change in percent of Vdrift_nominal | |
133 | // (under nominal conditions) at x,y,z,timeSec | |
134 | // | |
135 | ||
136 | // Get E-field Value -------------------------- | |
137 | Double_t dE = 0; //FIXME: eventually include Field-Inhomogenities | |
138 | ||
139 | // Get Temperature Value ---------------------- | |
140 | AliTPCTempMap *tempMap = new AliTPCTempMap(fSensTemp); | |
141 | Double_t tempValue = tempMap->GetTemperature(x, y, z, timeSec); | |
142 | Double_t dT = tempValue+273.15 - kstdT; | |
143 | ||
144 | // Get Main Pressure Value --------------------- | |
145 | // FIXME: READ REAL PRESSURE SENSOR | |
146 | // through TObject *fSensPres; | |
147 | // e.g. Double_t PO = fSensPres->GetValue(timeSec); | |
2aaa30ef | 148 | Double_t p0 = 744; |
1209231c | 149 | // recalculate Pressure according to height in TPC and transform to |
150 | // TORR (with simplified hydrostatic formula) | |
2aaa30ef | 151 | Double_t dP = p0 - krho*kg*y/10000 /1000*760 - kstdP; |
1209231c | 152 | |
153 | // Get GasComposition | |
154 | // FIXME: include Goofy values for CO2 and N2 conzentration out of DCS? | |
155 | // through TObject *fSensGasComp and calculate difference to stdCondit. | |
156 | Double_t dCco2 = 0; | |
157 | Double_t dCn2 = 0; | |
158 | ||
159 | // Calculate change in drift velocity in terms of Vdrift_nominal | |
160 | Double_t vdrift = VdriftLinearHyperplaneApprox(dE, dT, dP, dCco2, dCn2); | |
161 | ||
162 | return vdrift; | |
163 | ||
164 | tempMap->~AliTPCTempMap(); | |
165 | } | |
166 | ||
167 | //_____________________________________________________________________________ | |
168 | ||
169 | Double_t AliTPCCalibVdrift::GetMeanZVdriftChange(Double_t x, Double_t y, UInt_t timeSec) | |
170 | { | |
171 | // | |
172 | // Calculates Meanvalue in z direction of Vdrift change in percent | |
173 | // of Vdrift_nominal (under standard conditions) at position x,y,timeSec | |
174 | // with help of 'nPopints' base points | |
175 | // | |
176 | ||
177 | Int_t nPoints = 5; | |
178 | ||
2aaa30ef | 179 | Double_t vdriftSum = 0; |
1209231c | 180 | |
181 | for (Int_t i = 0; i<nPoints; i++) { | |
182 | Double_t z = (Double_t)i/(nPoints-1)*500-250; | |
2aaa30ef | 183 | vdriftSum = vdriftSum + GetVdriftChange(x, y, z, timeSec); |
1209231c | 184 | } |
185 | ||
2aaa30ef | 186 | Double_t meanZVdrift = vdriftSum/nPoints; |
1209231c | 187 | |
2aaa30ef | 188 | return meanZVdrift; |
1209231c | 189 | |
190 | } | |
191 | ||
192 | //_____________________________________________________________________________ | |
193 | ||
194 | TGraph *AliTPCCalibVdrift::MakeGraphMeanZVdriftChange(Double_t x, Double_t y, Int_t nPoints) | |
195 | { | |
196 | // | |
197 | // Make graph from start time to end time of Mean Drift Velocity in | |
198 | // Z direction at given x and y position | |
199 | // | |
200 | ||
2aaa30ef | 201 | UInt_t startTime = fSensTemp->GetStartTime(); |
202 | UInt_t endTime = fSensTemp->GetEndTime(); | |
1209231c | 203 | |
2aaa30ef | 204 | UInt_t stepTime = (endTime - startTime)/nPoints; |
1209231c | 205 | |
206 | ||
207 | Double_t *xvec = new Double_t[nPoints]; | |
208 | Double_t *yvec = new Double_t[nPoints]; | |
209 | ||
210 | for (Int_t ip=0; ip<nPoints; ip++) { | |
2aaa30ef | 211 | xvec[ip] = startTime+ip*stepTime; |
1209231c | 212 | yvec[ip] = GetMeanZVdriftChange(x, y, ip*stepTime); |
213 | } | |
214 | ||
215 | TGraph *graph = new TGraph(nPoints,xvec,yvec); | |
216 | ||
217 | delete [] xvec; | |
218 | delete [] yvec; | |
219 | ||
220 | graph->GetXaxis()->SetTimeDisplay(1); | |
221 | graph->GetXaxis()->SetLabelOffset(0.02); | |
222 | graph->GetXaxis()->SetTimeFormat("#splitline{%d/%m}{%H:%M}"); | |
223 | ||
224 | return graph; | |
225 | } |