ClassImp(AliTPCCalibVdrift)
- namespace paramDefinitions {
+namespace paramDefinitions {
- // Standard Conditions used as origin in the Magbolz simulations
- // Dimesions E [kV/cm], T [K], P [TORR], Cco2 [%], Cn2 [%]
- const Double_t kstdE = 400;
- const Double_t kstdT = 293;
- const Double_t kstdP = 744;
- const Double_t kstdCco2 = 9.52;
- const Double_t kstdCn2 = 4.76;
- // Driftvelocity at Standardcontitions [cm/microSec]
- const Double_t kstdVdrift = 2.57563;
-
- // Vdrift dependencies simulated with Magbolz [%(Vdrift)/[unit]]
- const Double_t kdvdE = 0.24;
- const Double_t kdvdT = 0.30;
- const Double_t kdvdP = -0.13;
- const Double_t kdvdCco2 = -6.60;
- const Double_t kdvdCn2 = -1.74;
+ // Standard Conditions used as origin in the Magbolz simulations
+ // Dimesions E [kV/cm], T [K], P [TORR], Cco2 [%], Cn2 [%]
+ const Double_t kstdE = 400;
+ const Double_t kstdT = 293;
+ const Double_t kstdP = 744;
+ const Double_t kstdCco2 = 9.52;
+ const Double_t kstdCn2 = 4.76;
+ // Driftvelocity at Standardcontitions [cm/microSec]
+ const Double_t kstdVdrift = 2.57563;
- Double_t krho = 0.934246; // density of TPC-Gas [kg/m^3]
- // method of calculation: weighted average
- Double_t kg = 9.81;
+ // Vdrift dependencies simulated with Magbolz [%(Vdrift)/[unit]]
+ const Double_t kdvdE = 0.24;
+ const Double_t kdvdT = 0.30;
+ const Double_t kdvdP = -0.13;
+ const Double_t kdvdCco2 = -6.60;
+ const Double_t kdvdCn2 = -1.74;
+ // 2nd order effect Taylor expansion
+ const Double_t kdvdE2nd = -0.00107628;
+ const Double_t kdvdT2nd = -0.00134441;
+ const Double_t kdvdP2nd = 0.000135325;
+ const Double_t kdvdCco22nd = 0.328761;
+ const Double_t kdvdCn22nd = 0.151605;
+
+ const Double_t torrTokPascal = 0.750061683;
+
+ Double_t krho = 0.934246; // density of TPC-Gas [kg/m^3]
+ // method of calculation: weighted average
+ Double_t kg = 9.81;
+
+ //
+ // Nominal value obtained from 2008 data
+ //
+ const Double_t kKelvin =273.15; // degree to Kelvin
+ const Double_t kNominalTemp =19.03; // mean between A and C side in degree
+ const Double_t kNominalPress =973.9; // pressure sensor - in mbar-
+ // calibDB->GetPressure(tstamp,irun,1)
}
+
using namespace paramDefinitions;
-AliTPCCalibVdrift::AliTPCCalibVdrift(AliTPCSensorTempArray *SensTemp, TObject *SensPres, TObject *SensGasComp):
+AliTPCCalibVdrift::AliTPCCalibVdrift(AliTPCSensorTempArray *SensTemp, AliDCSSensor *SensPres, TObject *SensGasComp):
TNamed(),
fSensTemp(0),
fSensPres(0),
- fSensGasComp(0)
+ fTempMap(0),
+ fSensGasComp(0),
+ fNominalTemp(0), // nominal temperature in Kelvin
+ fNominalPress(0) // nominal pressure in mbar
{
//
// Standard constructor
fSensTemp = SensTemp;
fSensPres = SensPres;
+ if (fSensTemp) {
+ fTempMap = new AliTPCTempMap(fSensTemp);
+ } else {
+ fTempMap = 0;
+ }
fSensGasComp = SensGasComp;
+ fNominalTemp = kNominalTemp;
+ fNominalPress= kNominalPress;
}
+//_____________________________________________________________________________
AliTPCCalibVdrift::AliTPCCalibVdrift(const AliTPCCalibVdrift& source) :
TNamed(source),
fSensTemp(source.fSensTemp),
fSensPres(source.fSensPres),
- fSensGasComp(source.fSensGasComp)
+ fTempMap(source.fTempMap),
+ fSensGasComp(source.fSensGasComp),
+ fNominalTemp(source.fNominalTemp), // nominal temperature in Kelvin
+ fNominalPress(source.fNominalPress) // nominal pressure in mbar
+
{
//
// Copy constructor
}
//_____________________________________________________________________________
-
AliTPCCalibVdrift& AliTPCCalibVdrift::operator=(const AliTPCCalibVdrift& source){
//
// assignment operator
{
//
// AliTPCCalibVdrift destructor
+ //
+
+}
+
+//_____________________________________________________________________________
+Double_t AliTPCCalibVdrift::GetPTRelative(UInt_t absTimeSec, Int_t side){
+ //
+ // Get Relative difference of p/T for given time stamp
+ // absTimeSec - absolute time in secounds
+ // side: 0 - A side | 1 - C side
+ //
+
+ TTimeStamp tstamp(absTimeSec);
+
+ if (!fSensPres||!fSensTemp) return 0;
+ Double_t pressure = fSensPres->GetValue(tstamp);
+ TLinearFitter * fitter = fTempMap->GetLinearFitter(3,side,tstamp);
+ if (!fitter) return 0;
+ TVectorD vec;
+ fitter->GetParameters(vec);
+ delete fitter;
+ if (vec[0]<10) return 0;
+ //
//
+ //
+ Double_t temperature = vec[0]; //vec[0] temeperature
+ Double_t tpnom = (fNominalTemp+kKelvin)/(fNominalPress);
+ Double_t tpmeasured = (temperature+kKelvin)/(pressure);
+ Double_t result = (tpmeasured-tpnom)/tpnom;
+
+ return result;
+
}
+
//_____________________________________________________________________________
Double_t AliTPCCalibVdrift::VdriftLinearHyperplaneApprox(Double_t dE, Double_t dT, Double_t dP, Double_t dCco2, Double_t dCn2)
{
//
- // Returns approximated value for the driftvelocity based on
- // linear Hyperplane approximation (~ Taylorapproximation of 1st order)
+ // Returns approximated value for the driftvelocity change (in percent)
+ // based on a Hyperplane approximation (~ Taylorapproximation of 2nd order)
//
- Double_t vdrift = (dE*kdvdE+dT*kdvdT+dP*kdvdP+dCco2*kdvdCco2+dCn2*kdvdCn2);
-
- return vdrift;
+ Double_t termE = dE*kdvdE + TMath::Power(dE,2)*kdvdE2nd;
+ Double_t termT = dT*kdvdT + TMath::Power(dT,2)*kdvdT2nd;
+ Double_t termP = dP*kdvdP + TMath::Power(dP,2)*kdvdP2nd;
+ Double_t termCo2 = dCco2*kdvdCco2 + TMath::Power(dCco2,2)*kdvdCco22nd;
+ Double_t termN2 = dCn2*kdvdCn2 + TMath::Power(dCn2,2)*kdvdCn22nd;
+
+ Double_t vdChange = termE+termT+termP+termCo2+termN2;
+
+ return vdChange;
}
+
//_____________________________________________________________________________
Double_t AliTPCCalibVdrift::GetVdriftNominal()
//_____________________________________________________________________________
-Double_t AliTPCCalibVdrift::GetVdriftChange(Double_t x, Double_t y, Double_t z, UInt_t timeSec)
+Double_t AliTPCCalibVdrift::GetVdriftChange(Double_t x, Double_t y, Double_t z, UInt_t absTimeSec)
{
//
// Calculates Vdrift change in percent of Vdrift_nominal
- // (under nominal conditions) at x,y,z,timeSec
+ // (under nominal conditions) at x,y,z at absolute time (in sec)
//
+ TTimeStamp tstamp(absTimeSec);
+
// Get E-field Value --------------------------
- Double_t dE = 0; //FIXME: eventually include Field-Inhomogenities
+ Double_t dE = 0.23; // StandardOffset if CE is set to 100kV
// Get Temperature Value ----------------------
- AliTPCTempMap *tempMap = new AliTPCTempMap(fSensTemp);
- Double_t tempValue = tempMap->GetTemperature(x, y, z, timeSec);
- Double_t dT = tempValue+273.15 - kstdT;
-
+ AliTPCTempMap *tempMap = fTempMap;
+ Double_t dT = 0;
+ if (fTempMap) {
+ Double_t tempValue = tempMap->GetTemperature(x, y, z, tstamp);
+ dT = tempValue + 273.15 - kstdT;
+ }
+
// Get Main Pressure Value ---------------------
- // FIXME: READ REAL PRESSURE SENSOR
- // through TObject *fSensPres;
- // e.g. Double_t PO = fSensPres->GetValue(timeSec);
- Double_t p0 = 744;
- // recalculate Pressure according to height in TPC and transform to
- // TORR (with simplified hydrostatic formula)
- Double_t dP = p0 - krho*kg*y/10000 /1000*760 - kstdP;
-
+ Double_t dP = 0;
+ if (fSensPres==0) {
+ // Just the pressure drop over the TPC height
+ dP = - krho*kg*y/10000*torrTokPascal;
+ } else {
+ // pressure sensors plus additional 0.4mbar overpressure within the TPC
+ Double_t pressure = fSensPres->GetValue(tstamp) + 0.4;
+ // calculate pressure drop according to height in TPC and transform to
+ // TORR (with simplified hydrostatic formula)
+ dP = (pressure - krho*kg*y/10000) * torrTokPascal - kstdP;
+ }
+
// Get GasComposition
- // FIXME: include Goofy values for CO2 and N2 conzentration out of DCS?
- // through TObject *fSensGasComp and calculate difference to stdCondit.
+ // FIXME: include Goofy values for CO2 and N2 conzentration out of OCDB
+ // Goofy not yet reliable ...
Double_t dCco2 = 0;
Double_t dCn2 = 0;
// Calculate change in drift velocity in terms of Vdrift_nominal
- Double_t vdrift = VdriftLinearHyperplaneApprox(dE, dT, dP, dCco2, dCn2);
+ Double_t vdChange = VdriftLinearHyperplaneApprox(dE, dT, dP, dCco2, dCn2);
- return vdrift;
+ return vdChange;
- tempMap->~AliTPCTempMap();
}
//_____________________________________________________________________________
-Double_t AliTPCCalibVdrift::GetMeanZVdriftChange(Double_t x, Double_t y, UInt_t timeSec)
+Double_t AliTPCCalibVdrift::GetMeanZVdriftChange(Double_t x, Double_t y, UInt_t absTimeSec)
{
//
// Calculates Meanvalue in z direction of Vdrift change in percent
- // of Vdrift_nominal (under standard conditions) at position x,y,timeSec
+ // of Vdrift_nominal (under standard conditions) at position x,y,absTimeSec
// with help of 'nPopints' base points
//
for (Int_t i = 0; i<nPoints; i++) {
Double_t z = (Double_t)i/(nPoints-1)*500-250;
- vdriftSum = vdriftSum + GetVdriftChange(x, y, z, timeSec);
+ vdriftSum = vdriftSum + GetVdriftChange(x, y, z, absTimeSec);
}
Double_t meanZVdrift = vdriftSum/nPoints;
for (Int_t ip=0; ip<nPoints; ip++) {
xvec[ip] = startTime+ip*stepTime;
- yvec[ip] = GetMeanZVdriftChange(x, y, ip*stepTime);
+ yvec[ip] = GetMeanZVdriftChange(x, y, fSensTemp->GetStartTime().GetSec() + ip*stepTime);
}
TGraph *graph = new TGraph(nPoints,xvec,yvec);
git://git.uio.no / u / mrichter / AliRoot.git / blobdiff