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24 // ********************************************************************
25 //
26 // G4HarmonicPolMagField implementation
27 //
28 // Author: V.Grichine, 03.02.1997
29 // -------------------------------------------------------------------
30
31 #include "G4HarmonicPolMagField.hh"
32 #include "globals.hh"
33
34 G4HarmonicPolMagField::G4HarmonicPolMagField() = default;
35
36 G4HarmonicPolMagField* G4HarmonicPolMagField::Clone() const
37 {
38 return new G4HarmonicPolMagField;
39 }
40
41 // -------------------------------------------------------------------
42
43 G4HarmonicPolMagField::~G4HarmonicPolMagField() = default;
44
45 // -------------------------------------------------------------------
46
47 void G4HarmonicPolMagField::GetFieldValue(const G4double yTrack[], // [7]
48 G4double B[] ) const // [3]
49 {
50 G4double a = 1.00 ; // mm -> m
51 G4double x = a*yTrack[0], y = a*yTrack[1], z = a*yTrack[2] ;
52 G4double x2 = x*x, y2 = y*y, z2 = z*z ;
53 G4double x3 = x2*x, y3 = y2*y, z3 = z2*z ;
54 G4double xy = x*y, xz = x*z, yz = y*z, xyz = x*y*z ;
55 static G4ThreadLocal G4double
56 c[24] = {
57 .010, .010, .010, // 3(0)
58 .0001, .0001, .0001, .0001, .0001, // 5(1)
59 .00001, .00001, .00001, .00001, .00001, .00001, .00001, // 7(2)
60 .000001, .000001, .000001, .000001, .000001, .000001,
61 .0000001, .0000001, .0000001 // 9(3)
62 } ; // total : 24
63
64 // for(auto i=0;i<24; ++i)
65 // {
66 // c[i] = 1.0*c[i] ;
67 // }
68 B[0] = c[1]
69 -2*c[3]*x + c[4]*z +c[6]*y -2*c[7]*x
70 -6*c[8]*xz + c[9]*(z2-x2) -2*c[10]*xy + c[11]*yz - 2*c[12]*xz
71 +c[13]*(y2-x2) - 6*c[14]*xy
72 -4*c[15]*(3*x*z2-x3) +c[16]*(z3-3*x2*z) - 6*c[17]*xyz +c[18]*y*(z2-x2)
73 -2*c[19]*(x*z2+x*y2-2*x3/3) + c[20]*z*(y2-x2) - 6*c[21]*xyz
74 +c[22]*(y3-3*x2*y) - 4*c[23]*(3*x*y2-x3) ;
75
76 B[1] = c[2]
77 +c[5]*z + c[6]*x + 2*c[7]*y
78 +c[10]*(z2-x2) + c[11]*xz +2*c[12]*yz +2*c[13]*xy + 3*c[14]*(y2-x2)
79 +c[17]*(z3-3*x2*z) + c[18]*(x*z2-x3/3) +2*c[19]*y*(z2-x2)
80 +2*c[20]*xyz
81 +3*c[21]*z*(y2-x2) + c[22]*(3*x*y2-x3) + 4*c[23]*(y3-3*x2*y) ;
82
83 B[2] = c[0]
84 +c[3]*z + c[4]*x + c[5]*y
85 +3*c[8]*(z2-x2) + 2*c[9]*xz + 2*c[10]*yz + c[11]*xy + c[12]*(y2-x2)
86 +4*c[15]*(z3-3*x2*z) + c[16]*(3*x*z2-x3) + 3*c[17]*(y*z2-x2*y)
87 +2*c[18]*xyz
88 +2*c[19]*z*(y2-x2) + c[20]*(x*y2-x3/3) + c[21]*(y3-3*x2*y) ;
89 for(auto i=0; i<3 ; ++i)
90 {
91 B[i] = 0.1*B[i] ;
92 }
93 }
94
95 // -----------------------------------------------------------------
96