]>
Commit | Line | Data |
---|---|---|
0116859c | 1 | /************************************************************************** |
2 | * Copyright(c) 1998-1999, 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 | //////////////////////////////////////////////////////////////////////////// | |
0116859c | 17 | // AliTPCExBTwist class // |
0116859c | 18 | //////////////////////////////////////////////////////////////////////////// |
b4caed64 | 19 | |
20 | ||
534fd34a | 21 | #include "AliMagF.h" |
22 | #include "TGeoGlobalMagField.h" | |
23 | #include "AliTPCcalibDB.h" | |
24 | #include "AliTPCParam.h" | |
25 | #include "AliLog.h" | |
0116859c | 26 | |
27 | #include "AliTPCExBTwist.h" | |
28 | ||
29 | AliTPCExBTwist::AliTPCExBTwist() | |
30 | : AliTPCCorrection("exb_twist","ExB twist"), | |
31 | fC1(0.),fC2(0.), | |
32 | fXTwist(0.),fYTwist(0.) | |
33 | { | |
34 | // | |
35 | // default constructor | |
36 | // | |
37 | } | |
38 | ||
39 | AliTPCExBTwist::~AliTPCExBTwist() { | |
40 | // | |
41 | // default destructor | |
42 | // | |
43 | } | |
44 | ||
534fd34a | 45 | |
46 | ||
e527a1b9 | 47 | void AliTPCExBTwist::Init() { |
48 | // | |
534fd34a | 49 | // Initialization funtion |
e527a1b9 | 50 | // |
51 | ||
534fd34a | 52 | AliMagF* magF= (AliMagF*)TGeoGlobalMagField::Instance()->GetField(); |
53 | if (!magF) AliError("Magneticd field - not initialized"); | |
54 | Double_t bzField = magF->SolenoidField()/10.; //field in T | |
55 | AliTPCParam *param= AliTPCcalibDB::Instance()->GetParameters(); | |
56 | if (!param) AliError("Parameters - not initialized"); | |
57 | Double_t vdrift = param->GetDriftV()/1000000.; // [cm/us] // From dataBase: to be updated: per second (ideally) | |
e527a1b9 | 58 | Double_t ezField = 400; // [V/cm] // to be updated: never (hopefully) |
59 | Double_t wt = -10.0 * (bzField*10) * vdrift / ezField ; | |
e527a1b9 | 60 | // Correction Terms for effective omegaTau; obtained by a laser calibration run |
534fd34a | 61 | SetOmegaTauT1T2(wt,fT1,fT2); |
e527a1b9 | 62 | |
e527a1b9 | 63 | |
e527a1b9 | 64 | } |
65 | ||
66 | void AliTPCExBTwist::Update(const TTimeStamp &/*timeStamp*/) { | |
67 | // | |
68 | // Update function | |
69 | // | |
534fd34a | 70 | AliMagF* magF= (AliMagF*)TGeoGlobalMagField::Instance()->GetField(); |
71 | if (!magF) AliError("Magneticd field - not initialized"); | |
72 | Double_t bzField = magF->SolenoidField()/10.; //field in T | |
73 | AliTPCParam *param= AliTPCcalibDB::Instance()->GetParameters(); | |
74 | if (!param) AliError("Parameters - not initialized"); | |
75 | Double_t vdrift = param->GetDriftV()/1000000.; // [cm/us] // From dataBase: to be updated: per second (ideally) | |
e527a1b9 | 76 | Double_t ezField = 400; // [V/cm] // to be updated: never (hopefully) |
77 | Double_t wt = -10.0 * (bzField*10) * vdrift / ezField ; | |
e527a1b9 | 78 | // Correction Terms for effective omegaTau; obtained by a laser calibration run |
534fd34a | 79 | SetOmegaTauT1T2(wt,fT1,fT2); |
80 | ||
e527a1b9 | 81 | |
e527a1b9 | 82 | } |
83 | ||
84 | ||
85 | ||
0116859c | 86 | void AliTPCExBTwist::GetCorrection(const Float_t x[],const Short_t roc,Float_t dx[]) { |
87 | // | |
88 | // Calculates the correction of a mismatch between the E and B field axis | |
89 | // | |
90 | ||
91 | const Float_t zstart=x[2]; | |
b1f0a2a5 | 92 | const Float_t zend =(roc%36<18?fgkTPCZ0:-fgkTPCZ0); |
0116859c | 93 | const Float_t zdrift=zstart-zend; |
94 | ||
95 | dx[0]=(fC2*fXTwist-fC1*fYTwist)*zdrift; | |
96 | dx[1]=(fC1*fXTwist+fC2*fYTwist)*zdrift; | |
97 | dx[2]=0.; | |
98 | } | |
99 | ||
b1f0a2a5 | 100 | void AliTPCExBTwist::Print(const Option_t* option) const { |
0116859c | 101 | // |
102 | // Print function to check the settings (e.g. the twist in the X direction) | |
103 | // option=="a" prints the C0 and C1 coefficents for calibration purposes | |
104 | // | |
105 | ||
106 | TString opt = option; opt.ToLower(); | |
107 | printf("%s\n",GetTitle()); | |
108 | ||
109 | printf(" - Twist settings: X-Twist: %1.5f rad, Y-Twist: %1.5f rad \n",fXTwist,fYTwist); | |
110 | if (opt.Contains("a")) { // Print all details | |
534fd34a | 111 | printf(" - T1: %1.4f, T2: %1.4f \n",fT1,fT2); |
0116859c | 112 | printf(" - C1: %1.4f, C2: %1.4f \n",fC1,fC2); |
113 | } | |
114 | ||
115 | ||
116 | } |