TrimCoilPhaseFit.cpp

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//
// Class TrimCoilPhaseFit
//   General rational function fit of the phase shift
//
// Copyright (c) 2018 - 2019, Jochem Snuverink, Paul Scherrer Institut, Villigen PSI, Switzerland
// All rights reserved
//
// Implemented as part of the PhD thesis
// "Precise Simulations of Multibunches in High Intensity Cyclotrons"
// and the paper
// "Matching of turn pattern measurements for cyclotrons using multiobjective optimization"
// (https://doi.org/10.1103/PhysRevAccelBeams.22.064602)
//
// This file is part of OPAL.
//
// OPAL is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// You should have received a copy of the GNU General Public License
// along with OPAL. If not, see <https://www.gnu.org/licenses/>.
//
#include "TrimCoils/TrimCoilPhaseFit.h"
 
TrimCoilPhaseFit::TrimCoilPhaseFit(double bmax,
                                   double rmin,
                                   double rmax,
                                   const std::vector<double>& coefnum,
                                   const std::vector<double>& coefdenom,
                                   const std::vector<double>& coefnumphi,
                                   const std::vector<double>& coefdenomphi):
    TrimCoilFit(bmax, rmin, rmax, coefnum, coefdenom, coefnumphi, coefdenomphi)
{}
 
void TrimCoilPhaseFit::doApplyField(const double r, const double z, const double phi_rad, double *br, double *bz)
{
    // check range
    if (r < rmin_m || r > rmax_m) return;
 
    double phase=0.0, d_phase=0.0, d2_phase=0.0;
    calculateRationalFunction(RADIUS, r, phase, d_phase, d2_phase);
    double phi = 0.0, d_phi = 0.0, d2_phi=0.0;
    calculateRationalFunction(PHI,    phi_rad, phi, d_phi, d2_phi);
 
    //std::cout << "r " << r << " dr " <<  dr << std::endl;
    double derivative =  d_phase * phi + phase *  d_phi;
    double der2       = d2_phase * phi + phase * d2_phi + 2*d_phi*d_phase;
 
    *bz += - bmax_m * derivative;
    *br += - bmax_m * der2 * z;
}