| Geant4 Cross Reference |
1 // 1
2 // *******************************************
3 // * License and Disclaimer
4 // *
5 // * The Geant4 software is copyright of th
6 // * the Geant4 Collaboration. It is provided
7 // * conditions of the Geant4 Software License
8 // * LICENSE and available at http://cern.ch/
9 // * include a list of copyright holders.
10 // *
11 // * Neither the authors of this software syst
12 // * institutes,nor the agencies providing fin
13 // * work make any representation or warran
14 // * regarding this software system or assum
15 // * use. Please see the license in the file
16 // * for the full disclaimer and the limitatio
17 // *
18 // * This code implementation is the result
19 // * technical work of the GEANT4 collaboratio
20 // * By using, copying, modifying or distri
21 // * any work based on the software) you ag
22 // * use in resulting scientific publicati
23 // * acceptance of all terms of the Geant4 Sof
24 // *******************************************
25 //
26 // G4ExactHelixStepper implementation
27 //
28 // Author: J.Apostolakis, 28.01.2005.
29 // Implementation adapted from Explici
30 // -------------------------------------------
31
32 #include "G4ExactHelixStepper.hh"
33 #include "G4PhysicalConstants.hh"
34 #include "G4ThreeVector.hh"
35 #include "G4LineSection.hh"
36
37 G4ExactHelixStepper::G4ExactHelixStepper(G4Mag
38 : G4MagHelicalStepper(EqRhs),
39 fBfieldValue(DBL_MAX, DBL_MAX, DBL_MAX)
40 {
41 }
42
43 G4ExactHelixStepper::~G4ExactHelixStepper() =
44
45 // -------------------------------------------
46
47 void
48 G4ExactHelixStepper::Stepper( const G4double y
49 const G4double*,
50 G4double h
51 G4double y
52 G4double y
53 {
54 const G4int nvar = 6;
55
56 G4int i;
57 G4ThreeVector Bfld_value;
58
59 MagFieldEvaluate(yInput, Bfld_value);
60 AdvanceHelix(yInput, Bfld_value, hstep, yOut
61
62 // We are assuming a constant field: helix i
63 //
64 for(i=0; i<nvar; ++i)
65 {
66 yErr[i] = 0.0 ;
67 }
68
69 fBfieldValue = Bfld_value;
70 }
71
72 // -------------------------------------------
73
74 void
75 G4ExactHelixStepper::DumbStepper( const G4doub
76 G4Thre
77 G4doub
78 G4doub
79 {
80 // Assuming a constant field: solution is a
81
82 AdvanceHelix(yIn, Bfld, h, yOut);
83
84 G4Exception("G4ExactHelixStepper::DumbSteppe
85 "GeomField0002", FatalException,
86 "Should not be called. Stepper m
87 }
88
89
90 // -------------------------------------------
91
92 G4double
93 G4ExactHelixStepper::DistChord() const
94 {
95 // Implementation : must check whether h/R >
96 // If( h/R < pi) DistChord=h/2*std::tan
97 // Else DistChord=R_helix
98
99 G4double distChord;
100 G4double Ang_curve=GetAngCurve();
101
102 if (Ang_curve<=pi)
103 {
104 distChord=GetRadHelix()*(1-std::cos(0.5*An
105 }
106 else if(Ang_curve<twopi)
107 {
108 distChord=GetRadHelix()*(1+std::cos(0.5*(t
109 }
110 else
111 {
112 distChord=2.*GetRadHelix();
113 }
114
115 return distChord;
116 }
117
118 // -------------------------------------------
119
120 G4int
121 G4ExactHelixStepper::IntegratorOrder() const
122 {
123 return 1;
124 }
125