musrsim/geant4/LEMuSR/include/LEMuSRElectricField.hh

133 lines
5.0 KiB
C++

//$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$//*
// LOW ENERGY MUON SPIN RELAXATION, ROTATION, RADIATION
//
// ID :LEMuSRElectricField.hh , v 1.3
// AUTHOR: Taofiq PARAISO
// DATE : 2004-09-17 10:20
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// Electric Field
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#ifndef LEMUSRELECTRICFIELD_H
#define LEMUSRELECTRICFIELD_H 1
#include"G4ElectricField.hh"
#include"G4ElectroMagneticField.hh"
#include "globals.hh"
#include "G4ios.hh"
#include <iomanip>
#include <iostream>
#include <fstream>
#include <vector>
#include <cmath>
#include "CLHEP/Matrix/Vector.h"
#include "CLHEP/Matrix/Matrix.h"
/**
* The goal of the LEMuSRElectricField class is to read field maps generated by
* COMSOL Multiphysics.
* \image html field.gif Example of a field map generated using COMSOL.
* Those field maps are shared into three ascii files, one per field component,
* in the format (x y z B_i). The first line in the file contains
* the labels. The second line is (x_min y_min z_min B_i) and the last line
* is (x_max y_max z_max B_i).
* LEMuSRElectricField reads those files and store them in an array.
* Some important parameters must be specified to read a field map:
* -# <b> The number of points</b> along each axis which was defined in COMSOL
* before exporting the maps.
* - It is very important to check that the number of points do not
* exceed the size of the array defined in LEMuSRElectricField.hh
* -# <b> The unit of the map</b>, which is an important parameter because the
* default distance unit in COMSOL is the meter.
* - A different unit has an influence
* on the coordinates reading, but also on the actual field value which has to
* be scaled consequently.
* -# The voltage to use. Indeed,the field maps are generated for 1kV potential.
* The user should indicate the actual voltage to multiply the fields values.
* -# The offset along z axis, in case the map is not centered on the actual
* postition of the field. This is the case for the third lense field for example:
* the map is centered on (0, 0, 0) and the center or the lens is at (0, 0, -567mm).
* .
* The field maps can be very heavy files and reading them can cost a lot of time.
* For this reason, it is possible to write the field map array in a single file
* after the first reading. Such maps files have been produced for the third
* lens, the anode and the sample.
*/
class LEMuSRElectricField : public G4ElectricField
{
public:
//! Constructor from three field maps
LEMuSRElectricField(G4double fieldval,G4String Xfile,
G4String Yfile,
G4String Zfile,G4String map_length_unit,
G4double Offset, G4double nx, G4double ny, G4double nz);//offset must be entered in millimeter
//! Contructor from a single field map
LEMuSRElectricField(G4double fieldval,G4String file,G4String map_length_unit,
G4double Offset, G4double nx, G4double ny, G4double nz);
~LEMuSRElectricField();
//! Returns the field value at Point[4] space-time coordinate.
/*!
* This method is in charge of returning the field value for a given position.
* It scales the field array according to the unit and interpolates the field
* value from the cube surrounding Point[4].
*/
void GetFieldValue(const G4double Point[4], G4double *Bfield) const;
//! Debugging test.
void Test();
public:
// std::vector< std::vector< std::vector< G4double > > > xField; // vector of
// vector of
// vector of G4doubles [[[a]i]j]k
// std::vector< std::vector< std::vector< G4double > > > yField;
// std::vector< std::vector< std::vector< G4double > > > zField;
//! Bx, By, Bz, for all x positions
G4double xField[90][90][201];
//! Bx, By, Bz, for all y positions
G4double yField[90][90][201];
//! Bx, By, Bz, for all z positions
G4double zField[90][90][201];
//! The physical limits of the defined region
G4double minx, maxx, miny, maxy, minz, maxz;
G4double
//! Number of divisions along axis.
nx,ny,nz,
//! Offset along propagation axis
zOffset,
//! Actual voltage value.
FieldVal;
//! Unit of the field map.
G4String map_unit;
};
#endif