Completely Updated (Mario Sitta)
[u/mrichter/AliRoot.git] / STEER / AliMagFC.cxx
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aee8290b 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
acd84897 16/* $Id$ */
d8408e76 17
116cbefd 18//-------------------------------------------------------------------------
116cbefd 19// Constant magnetic field class
5d8718b8 20// Used by AliRun class
21// Author:
116cbefd 22//-------------------------------------------------------------------------
23
fb17acd4 24#include <stdlib.h>
aee8290b 25
594d8990 26#include "AliLog.h"
aee8290b 27#include "AliMagFC.h"
28
29ClassImp(AliMagFC)
30
31//________________________________________
d0f1ee3b 32AliMagFC::AliMagFC(const char *name, const char *title, Int_t integ,
33 Float_t factor, Float_t fmax)
c28c3a0b 34 : AliMagF(name,title,integ,factor,fmax),
35 fCompensator(kFALSE)
aee8290b 36{
37 //
38 // Standard constructor
39 //
aee8290b 40 fType = kConst;
d8408e76 41 fMap = 1;
aee8290b 42}
43
44//________________________________________
6f3038e9 45void AliMagFC::Field(Float_t *x, Float_t *b) const
aee8290b 46{
47 //
48 // Method to return the field in a point
49 //
50 b[0]=b[1]=b[2]=0;
51 if(fMap==1) {
52 if(TMath::Abs(x[2])<700 && x[0]*x[0]+(x[1]+30)*(x[1]+30) < 560*560) {
53 b[2]=2;
54 } else {
575c700d 55 if ( -725 >= x[2] && x[2] >= -1225 ) {
56 Float_t dz = TMath::Abs(-975-x[2])*0.01;
57 b[0] = - (1-0.1*dz*dz)*7;
aee8290b 58 }
59 else {
575c700d 60 ZDCField(x, b);
d95ea23f 61 }
62 }
575c700d 63 if(fFactor!=1) {
64 b[0]*=fFactor;
65 b[1]*=fFactor;
66 b[2]*=fFactor;
d95ea23f 67 }
575c700d 68 } else {
594d8990 69 AliFatal(Form("Invalid field map for constant field %d",fMap));
575c700d 70 }
71}
72
73
6f3038e9 74void AliMagFC::ZDCField(Float_t *x, Float_t *b) const
575c700d 75{
76//This is the ZDC part
c28c3a0b 77 Float_t rad2 = x[0] * x[0] + x[1] * x[1];
2e9eb88a 78
c28c3a0b 79 if (fCompensator && (x[2] > 919. && x[2] < 1231.) && rad2 < 16.) {
80 // Compensator magnet at z = 1075 m
81 b[0] = 10.9;
82 b[1] = 0.;
83 b[2] = 0.;
84 return;
85 }
86
87
575c700d 88 if(x[2] < kCORBEG2 && x[2] > kCOREND2){
89 if(rad2<kCOR2RA2){
90 b[0] = - kFCORN2;
91 }
d95ea23f 92 }
575c700d 93 else if(x[2] < kZ1BEG && x[2] > kZ1END){
94 if(rad2<kZ1RA2){
95 b[0] = kG1*x[1];
53cc0d31 96 b[1] = kG1*x[0];
575c700d 97 }
d95ea23f 98 }
575c700d 99 else if(x[2] < kZ2BEG && x[2] > kZ2END){
100 if(rad2<kZ2RA2){
101 b[0] = -kG1*x[1];
53cc0d31 102 b[1] = -kG1*x[0];
575c700d 103 }
d95ea23f 104 }
575c700d 105 else if(x[2] < kZ3BEG && x[2] > kZ3END){
106 if(rad2<kZ3RA2){
107 b[0] = -kG1*x[1];
53cc0d31 108 b[1] = -kG1*x[0];
575c700d 109 }
d95ea23f 110 }
575c700d 111 else if(x[2] < kZ4BEG && x[2] > kZ4END){
112 if(rad2<kZ4RA2){
113 b[0] = kG1*x[1];
53cc0d31 114 b[1] = kG1*x[0];
575c700d 115 }
d95ea23f 116 }
575c700d 117 else if(x[2] < kD1BEG && x[2] > kD1END){
118 if(rad2<kD1RA2){
119 b[1] = -kFDIP;
120 }
aee8290b 121 }
575c700d 122 else if(x[2] < kD2BEG && x[2] > kD2END){
123 if(((x[0]-kXCEN1D2)*(x[0]-kXCEN1D2)+(x[1]-kYCEN1D2)*(x[1]-kYCEN1D2))<kD2RA2
124 || ((x[0]-kXCEN2D2)*(x[0]-kXCEN2D2)+(x[1]-kYCEN2D2)*(x[1]-kYCEN2D2))<kD2RA2){
125 b[1] = kFDIP;
126 }
aee8290b 127 }
575c700d 128
aee8290b 129}