1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
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 **************************************************************************/
18 //-------------------------------------------------------------------------
19 // Constant magnetic field class
20 // Used by AliRun class
22 //-------------------------------------------------------------------------
31 //________________________________________
35 fBeamType(kBeamTypepp),
44 // Default constructor
48 //________________________________________
49 AliMagFC::AliMagFC(const char *name, const char *title, Int_t integ,
50 Float_t factor, Float_t fmax)
51 : AliMagF(name,title,integ,factor,fmax),
53 fBeamType(kBeamTypepp),
63 // Standard constructor
68 //////////////////////////////////////////////////////////////////////
69 // ---- Magnetic field values (according to beam type and energy) ----
70 if(fBeamType==kBeamTypepp && fBeamEnergy==5000.){
72 fQuadGradient = 15.7145;
73 fDipoleField = 27.0558;
77 fACorr1Field = -13.2143;
78 fACorr2Field = -11.9909;
79 } else if (fBeamType == kBeamTypepp && fBeamEnergy == 450.) {
81 Float_t const kEnergyRatio = fBeamEnergy / 7000.;
83 fQuadGradient = 22.0002 * kEnergyRatio;
84 fDipoleField = 37.8781 * kEnergyRatio;
86 fCCorrField = 9.6908 * kEnergyRatio;
88 fACorr1Field = -13.2014;
89 fACorr2Field = -9.6908;
90 } else if ((fBeamType == kBeamTypepp && fBeamEnergy == 7000.) ||
91 (fBeamType == kBeamTypeAA))
93 // Pb-Pb @ 2.7+2.7 TeV or p-p @ 7+7 TeV
94 fQuadGradient = 22.0002;
95 fDipoleField = 37.8781;
99 fACorr1Field = -13.2014;
100 fACorr2Field = -9.6908;
104 //________________________________________
105 void AliMagFC::Field(Float_t *x, Float_t *b) const
108 // Method to return the field in a point
112 if(TMath::Abs(x[2])<700 && x[0]*x[0]+(x[1]+30)*(x[1]+30) < 560*560) {
116 if(-725 >= x[2] && x[2] >= -1225 ){
117 Float_t dz = TMath::Abs(-975-x[2])*0.01;
118 b[0] = - (1-0.1*dz*dz)*7;
132 AliFatal(Form("Invalid field map for constant field %d",fMap));
136 //___________________________________________________
137 void AliMagFC::ZDCField(Float_t *x, Float_t *b) const
139 // ---- This is the ZDC part
141 Float_t rad2 = x[0] * x[0] + x[1] * x[1];
143 // SIDE C **************************************************
145 if(x[2] < kCCorrBegin && x[2] > kCCorrEnd && rad2 < kCCorrSqRadius){
152 else if(x[2] < kCQ1Begin && x[2] > kCQ1End && rad2 < kCQ1SqRadius){
153 b[0] = fQuadGradient*x[1];
154 b[1] = fQuadGradient*x[0];
157 else if(x[2] < kCQ2Begin && x[2] > kCQ2End && rad2 < kCQ2SqRadius){
158 b[0] = -fQuadGradient*x[1];
159 b[1] = -fQuadGradient*x[0];
162 else if(x[2] < kCQ3Begin && x[2] > kCQ3End && rad2 < kCQ3SqRadius){
163 b[0] = -fQuadGradient*x[1];
164 b[1] = -fQuadGradient*x[0];
167 else if(x[2] < kCQ4Begin && x[2] > kCQ4End && rad2 < kCQ4SqRadius){
168 b[0] = fQuadGradient*x[1];
169 b[1] = fQuadGradient*x[0];
172 else if(x[2] < kCD1Begin && x[2] > kCD1End && rad2 < kCD1SqRadius){
177 else if(x[2] < kCD2Begin && x[2] > kCD2End){
178 if(((x[0]-kCD2XCentre1)*(x[0]-kCD2XCentre1)+(x[1]*x[1]))<kCD2SqRadius
179 || ((x[0]-kCD2XCentre2)*(x[0]-kCD2XCentre2)+(x[1]*x[1]))<kCD2SqRadius){
180 b[1] = -fDipoleField;
187 // SIDE A **************************************************
189 if(fCompensator && (x[2] > kACorr1Begin && x[2] < kACorr1End) && rad2 < kCCorr1SqRadius) {
190 // Compensator magnet at z = 1075 m
199 if(x[2] > kACorr2Begin && x[2] < kACorr2End && rad2 < kCCorr2SqRadius){
206 else if(x[2] > kAQ1Begin && x[2] < kAQ1End && rad2 < kAQ1SqRadius){
207 // First quadrupole of inner triplet de-focussing in x-direction
208 b[0] = -fQuadGradient*x[1];
209 b[1] = -fQuadGradient*x[0];
212 else if(x[2] > kAQ2Begin && x[2] < kAQ2End && rad2 < kAQ2SqRadius){
213 b[0] = fQuadGradient*x[1];
214 b[1] = fQuadGradient*x[0];
217 else if(x[2] > kAQ3Begin && x[2] < kAQ3End && rad2 < kAQ3SqRadius){
218 b[0] = fQuadGradient*x[1];
219 b[1] = fQuadGradient*x[0];
222 else if(x[2] > kAQ4Begin && x[2] < kAQ4End && rad2 < kAQ4SqRadius){
223 b[0] = -fQuadGradient*x[1];
224 b[1] = -fQuadGradient*x[0];
227 else if(x[2] > kAD1Begin && x[2] < kAD1End && rad2 < kAD1SqRadius){
229 b[1] = -fDipoleField;
232 else if(x[2] > kAD2Begin && x[2] < kAD2End){
233 if(((x[0]-kAD2XCentre1)*(x[0]-kAD2XCentre1)+(x[1]*x[1])) < kAD2SqRadius
234 || ((x[0]-kAD2XCentre2)*(x[0]-kAD2XCentre2)+(x[1]*x[1])) < kAD2SqRadius){