| 1 | //
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| 2 | // ********************************************************************
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| 3 | // * License and Disclaimer *
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| 4 | // * *
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| 5 | // * The Geant4 software is copyright of the Copyright Holders of *
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| 6 | // * the Geant4 Collaboration. It is provided under the terms and *
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| 7 | // * conditions of the Geant4 Software License, included in the file *
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| 8 | // * LICENSE and available at http://cern.ch/geant4/license . These *
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| 9 | // * include a list of copyright holders. *
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| 10 | // * *
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| 11 | // * Neither the authors of this software system, nor their employing *
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| 12 | // * institutes,nor the agencies providing financial support for this *
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| 13 | // * work make any representation or warranty, express or implied, *
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| 14 | // * regarding this software system or assume any liability for its *
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| 15 | // * use. Please see the license in the file LICENSE and URL above *
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| 16 | // * for the full disclaimer and the limitation of liability. *
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| 17 | // * *
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| 18 | // * This code implementation is the result of the scientific and *
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| 19 | // * technical work of the GEANT4 collaboration. *
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| 20 | // * By using, copying, modifying or distributing the software (or *
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| 21 | // * any work based on the software) you agree to acknowledge its *
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| 22 | // * use in resulting scientific publications, and indicate your *
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| 23 | // * acceptance of all terms of the Geant4 Software license. *
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| 24 | // ********************************************************************
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| 25 | //
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| 26 | // $Id: G4LineCurrentMagField.cc,v 1.6 2006/06/29 18:24:13 gunter Exp $
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| 27 | // GEANT4 tag $Name: HEAD $
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| 28 | // -------------------------------------------------------------------
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| 29 |
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| 30 | #include "G4LineCurrentMagField.hh"
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| 31 | #include "globals.hh"
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| 32 |
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| 33 | G4LineCurrentMagField::G4LineCurrentMagField(G4double pFieldConstant)
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| 34 | {
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| 35 | fFieldConstant = pFieldConstant ;
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| 36 | }
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| 37 | ////////////////////////////////////////////////////////////////////////
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| 38 |
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| 39 | G4LineCurrentMagField::~G4LineCurrentMagField()
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| 40 | {
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| 41 | }
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| 42 |
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| 43 | ///////////////////////////////////////////////////////////////////////////
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| 44 |
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| 45 |
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| 46 | void G4LineCurrentMagField::GetFieldValue( const G4double yTrack[7],
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| 47 | G4double B[3] ) const
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| 48 | {
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| 49 | // G4double fFieldConstant = 100 ;
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| 50 | G4double a = 1.00*mm ; // mm -> m
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| 51 | G4double x = a*yTrack[0], y = a*yTrack[1] ;
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| 52 | G4double x2 = x*x, y2 = y*y, r2 = x2 + y2 ;
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| 53 | G4double r = std::sqrt(r2+a*a) ;
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| 54 | G4double Br = fFieldConstant/r;
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| 55 | B[0] = -Br*y/r ;
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| 56 | B[1] = Br*x/r ;
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| 57 | B[2] = 0 ;
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| 58 | }
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| 59 |
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| 60 | // -----------------------------------------------------------------
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