| Geant4 Cross Reference |
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25 //
26 // G4FieldManager
27 //
28 // Class description:
29 //
30 // A class to manage (Store) a pointer to the
31 // describes the field of a detector (magnetic
32 // Also stores a reference to the chord finder
33 //
34 // The G4FieldManager class exists to allow th
35 // the electric, magnetic and/or other field(s
36 //
37 // A field manager can be set to a logical vol
38 // in order to vary its field from that of the
39 // a zero or constant field can override a glo
40 // less exact version can override the externa
41 // or higher precision for tracking can be spe
42 // stepper can be chosen for different volumes
43 //
44 // It also stores a pointer to the ChordFinder
45 // propagation in this field. All geometrical
46 // in the field is handled by this ChordFinder
47 //
48 // G4FieldManager allows the other classes/obj
49 // & other class categories) to find out wheth
50 // exists and what that object is.
51 //
52 // The Chord Finder must be created either by
53 // for a Magnetic Field or by the user creatin
54 // "manually" and setting this pointer.
55 //
56 // A default FieldManager is created by the si
57 // G4NavigatorForTracking and exists before ma
58 // However a new one can be created and given
59 //
60 // Our current design envisions that one Field
61 // valid for each region detector.
62 //
63 // It is expected that a particular geometrica
64 // By default a Field Manager is created for t
65 // will be utilised for all volumes unless it
66 // field manager.
67 // Note also that a region with both electric
68 // have these treated as one field.
69 // Similarly it could be extended to treat oth
70 // components of a single field type.
71
72 // Author: John Apostolakis, 10.03.97 - design
73 // -------------------------------------------
74 #ifndef G4FIELDMANAGER_HH
75 #define G4FIELDMANAGER_HH 1
76
77 #include "globals.hh"
78
79 class G4Field;
80 class G4MagneticField;
81 class G4ChordFinder;
82 class G4Track; // Forward reference for param
83
84 class G4FieldManager
85 {
86 public: // with description
87 G4FieldManager(G4Field* detectorField = nu
88 G4ChordFinder* pChordFinder
89 G4bool b = true ); // field
90 // General constructor for any field.
91 // -> Must be set with field and chordfi
92 G4FieldManager(G4MagneticField* detectorMa
93 // Creates ChordFinder
94 // -> Assumes pure magnetic field (so en
95
96 virtual ~G4FieldManager();
97
98 G4FieldManager(const G4FieldManager&) = de
99 G4FieldManager& operator=(const G4FieldMan
100
101 G4bool SetDetectorField(G4Field* detectorF
102 // Pushes the field to the equation.
103 // Failure to push the field (due to abs
104 // stepper or equation) is
105 // - '0' = quiet : Do not comp
106 // (It will s
107 // - '1' = warn : a warning i
108 // - '2'/else = FATAL : a fatal err
109 // Returns success (true) or failure (fa
110
111 inline void ProposeDetectorField(G4Field*
112 // Pushes the field to this class only -
113 // Should be used to initialise this fi
114 // the chord finder and its dependent cl
115 // User is then responsible to ensure th
116 // i) an equation, stepper, driver a
117 // ii) this field is used by the equa
118
119 inline void ChangeDetectorField(G4Field*
120 // Pushes the field to the equation ( &
121 // Can be used only once the equation, s
122 // have all been created. Else it is an
123
124 inline const G4Field* GetDetectorField()
125 inline G4bool DoesFieldExist() co
126 // Set, get and check the field object
127
128 void CreateChordFinder(G4MagneticField* de
129 inline void SetChordFinder(G4ChordFinder*
130 inline G4ChordFinder* GetChordFinder();
131 inline const G4ChordFinder* GetChordFinder
132 // Create, set or get the associated Cho
133
134 virtual void ConfigureForTrack( const G4
135 // Setup the choice of the configurable
136 // relying on the current track's energy
137 // Note: in addition to the values of me
138 // a user can use this to change t
139
140 // static functions to handle global field
141 static void SetGlobalFieldManager(G4FieldM
142 static G4FieldManager* GetGlobalFieldManag
143
144 public: // with description
145
146 inline G4double GetDeltaIntersection() con
147 // Accuracy for boundary intersection.
148
149 inline G4double GetDeltaOneStep() const;
150 // Accuracy for one tracking/physics ste
151
152 inline void SetAccuraciesWithDeltaOneStep(
153 // Sets both accuracies, maintaining a f
154 // of volume Intersection and Integratio
155
156 inline void SetDeltaOneStep(G4double v
157 // Set accuracy for integration of one s
158 inline void SetDeltaIntersection(G4dou
159 // Set accuracy of intersection of a vo
160
161 inline G4double GetMinimumEpsilonStep() c
162 G4bool SetMinimumEpsilonStep( G4
163 // Minimum for Relative accuracy of a St
164
165 inline G4double GetMaximumEpsilonStep() c
166 G4bool SetMaximumEpsilonStep( G4
167 // Maximum for Relative accuracy of a St
168
169 inline G4bool DoesFieldChangeEnergy() co
170 inline void SetFieldChangesEnergy(G4bo
171 // For electric field this should be tru
172 // For magnetic field this should be fal
173
174 virtual G4FieldManager* Clone() const;
175 // Needed for multi-threading, create a
176
177 public:
178 static G4double GetMaxAcceptedEpsilon();
179 static G4bool SetMaxAcceptedEpsilon(G4do
180 // Set value -- within limits.
181 // If it fails, with softFail=true it giv
182
183 protected:
184 static G4double fMaxAcceptedEpsilon;
185 static constexpr G4double fMinAcceptedEpsi
186 // Epsilon_min/max values must be smalle
187
188 static constexpr G4double fMaxWarningEpsil
189 static constexpr G4double fMaxFinalEpsilon
190
191 static G4bool fVerboseConstruc
192 // Control verbosity of constructors
193
194 private:
195
196 void InitialiseFieldChangesEnergy();
197 // Check whether field/equation change t
198 // and sets the data member accordingly
199 // Note: does not handle special cases -
200 // separately (e.g. magnetic monopole i
201
202 protected:
203 void ReportBadEpsilonValue(G4ExceptionDes
204 G4String& name
205
206 private:
207 G4Field* fDetectorField = nullptr;
208 G4ChordFinder* fChordFinder = nullptr;
209 // Dependent objects -- with state that
210
211 G4bool fAllocatedChordFinder = false; // D
212 // c
213 // INVARIANTS of tracking ---------------
214 //
215 // 1. 'CONSTANTS' - default values for ac
216 //
217 const G4double fEpsilonMinDefault= 5.0e-5;
218 const G4double fEpsilonMaxDefault= 1.0e-3;
219
220 static G4double fDefault_Delta_One_Step_Va
221 static G4double fDefault_Delta_Intersectio
222 // Default values for accuracy parameter
223
224 // 2. CHARACTERISTIC of field
225 //
226 G4bool fFieldChangesEnergy = false;
227
228 // 3. PARAMETERS that determine the accur
229 //
230 G4double fDelta_One_Step_Value; // f
231 G4double fDelta_Intersection_Val; // f
232 // Values for the required accuracies
233
234 G4double fEpsilonMin;
235 G4double fEpsilonMax;
236 // Values for the small possible relativ
237 // (corresponding to the greatest possib
238
239 static G4ThreadLocal G4FieldManager* fGlob
240 // Global field manager set by G4Transpo
241 // to allow accessing the global field w
242 // on navigation
243 };
244
245 // Implementation of inline functions
246
247 #include "G4FieldManager.icc"
248
249 #endif
250