Line data Source code
1 : #ifndef CRPROPA_MAGNETICFIELD_H
2 : #define CRPROPA_MAGNETICFIELD_H
3 :
4 : #include "crpropa/Units.h"
5 : #include "crpropa/Vector3.h"
6 : #include "crpropa/Referenced.h"
7 :
8 : #ifdef CRPROPA_HAVE_MUPARSER
9 : #include "muParser.h"
10 : #endif
11 :
12 : namespace crpropa {
13 : /**
14 : * \addtogroup MagneticFields
15 : * @{
16 : */
17 :
18 : /**
19 : @class MagneticField
20 : @brief Abstract base class for magnetic fields.
21 : */
22 0 : class MagneticField: public Referenced {
23 : public:
24 0 : virtual ~MagneticField() {
25 0 : }
26 0 : virtual Vector3d getField(const Vector3d &position) const {
27 0 : return Vector3d(0,0,0);
28 : };
29 5760379 : virtual Vector3d getField(const Vector3d &position, double z) const {
30 5760379 : return getField(position);
31 : };
32 : };
33 :
34 : /**
35 : @class PeriodicMagneticField
36 : @brief Magnetic field decorator implementing periodic fields.
37 :
38 : The periodic cube is defined by its origin (Vector3d) and an
39 : extends parameter (Vector3d). All points x=(x_1, x_2, x_3)
40 : that are described by x_i = origin_i + epsilon * extend_i,
41 : with epsilon = 0...1 are within the base cube. Magnetic field
42 : strengths for all positions outside of this cube are calculated
43 : based on the values in the base cube.
44 : This can be done periodically or reflectively.
45 : */
46 :
47 : class PeriodicMagneticField: public MagneticField {
48 : ref_ptr<MagneticField> field;
49 : Vector3d origin, extends;
50 : bool reflective;
51 : public:
52 : /**
53 : * Constructor
54 : * @param field magnetic field reference pointer
55 : * @param extends length, width, and height of the base cube
56 : */
57 : PeriodicMagneticField(ref_ptr<MagneticField> field,
58 : const Vector3d &extends);
59 : /**
60 : * Constructor
61 : * @param field magnetic field reference pointer
62 : * @param extends length, width, and height of the base cube
63 : * @param origin defines the reference position
64 : * @param reflective for periodic or reflective behavior
65 : */
66 : PeriodicMagneticField(ref_ptr<MagneticField> field, const Vector3d &extends,
67 : const Vector3d &origin, bool reflective);
68 : Vector3d &getOrigin();
69 : void setOrigin(const Vector3d &origin);
70 : Vector3d &getExtends();
71 : void setExtends(const Vector3d &origin);
72 : bool isReflective();
73 : void setReflective(bool reflective);
74 : Vector3d getField(const Vector3d &position) const;
75 : };
76 :
77 : /**
78 : @class MagneticFieldList
79 : @brief Magnetic field decorator implementing a superposition of fields.
80 : */
81 2 : class MagneticFieldList: public MagneticField {
82 : std::vector<ref_ptr<MagneticField> > fields;
83 : public:
84 : void addField(ref_ptr<MagneticField> field);
85 : Vector3d getField(const Vector3d &position) const;
86 : };
87 :
88 : /**
89 : @class MagneticFieldEvolution
90 : @brief Magnetic field decorator implementing an evolution of type (1+z)^m.
91 : */
92 2 : class MagneticFieldEvolution: public MagneticField {
93 : ref_ptr<MagneticField> field;
94 : double m;
95 : public:
96 : /**
97 : * Constructor
98 : * @param field magnetic field reference pointer
99 : * @param m cosmic evolution parameter
100 : */
101 : MagneticFieldEvolution(ref_ptr<MagneticField> field, double m);
102 : Vector3d getField(const Vector3d &position, double z = 0) const;
103 : };
104 :
105 : /**
106 : @class UniformMagneticField
107 : @brief Magnetic field with one B-field vector.
108 : */
109 : class UniformMagneticField: public MagneticField {
110 : Vector3d value;
111 : public:
112 : /**
113 : * Constructor
114 : * @param value magnetic field strength
115 : */
116 35 : UniformMagneticField(const Vector3d &value) :
117 35 : value(value) {
118 : }
119 5760342 : Vector3d getField(const Vector3d &position) const {
120 5760342 : return value;
121 : }
122 : };
123 :
124 : /**
125 : @class MagneticDipoleField
126 : @brief Magnetic dipole field defined by the magnetic moment and the 'core' radius.
127 : */
128 1 : class MagneticDipoleField: public MagneticField {
129 : Vector3d origin;
130 : Vector3d moment;
131 : double radius;
132 : public:
133 : /**
134 : * Constructor
135 : * @param origin singularity of the dipole field
136 : * @param moment magnetic moment of the dipole field
137 : * @param radius inside a radius around the origin the
138 : * magnetic field is constant: moment * 2 * mu0 / 3
139 : */
140 1 : MagneticDipoleField(const Vector3d &origin, const Vector3d &moment, const double radius) :
141 1 : origin(origin), moment(moment), radius(radius) {
142 : }
143 : Vector3d getField(const Vector3d &position) const;
144 : };
145 :
146 : #ifdef CRPROPA_HAVE_MUPARSER
147 : /**
148 : @class RenormalizeMagneticField
149 : @brief Renormalize strength of a given field by expression in which B is the strength variable.
150 : */
151 : class RenormalizeMagneticField: public MagneticField {
152 : ref_ptr<MagneticField> field;
153 : std::string expression;
154 : mu::Parser *p;
155 : double Bmag;
156 : public:
157 : /**
158 : * Constructor
159 : * @param field magnetic field reference pointer
160 : * @param expression muParser expression used to renormalize the field,
161 : * e.g., "gauss".
162 : */
163 : RenormalizeMagneticField(ref_ptr<MagneticField> field, std::string expression);
164 1 : ~RenormalizeMagneticField() { delete p; }
165 : Vector3d getField(const Vector3d &position);
166 : };
167 : #endif
168 :
169 : /** @} */
170 : } // namespace crpropa
171 :
172 : #endif // CRPROPA_MAGNETICFIELD_H
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