ParallelTTracker.cpp

//
// Class ParallelTTracker
//   OPAL-T tracker.
//   The visitor class for tracking particles with time as independent
//   variable.
//
// Copyright (c) 200x - 2020, Paul Scherrer Institut, Villigen PSI, Switzerland
// All rights reserved
//
// 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 "Algorithms/ParallelTTracker.h"

#include <cfloat>
#include <iostream>
#include <fstream>
#include <iomanip>
#include <sstream>
#include <string>
#include <limits>
#include <cmath>

#include "Algorithms/OrbitThreader.h"
#include "Algorithms/CavityAutophaser.h"
#include "Beamlines/Beamline.h"
#include "Beamlines/FlaggedBeamline.h"
#include "Lines/Sequence.h"

#include "Solvers/CSRWakeFunction.hh"

#include "AbstractObjects/OpalData.h"

#include "BasicActions/Option.h"
#include "Utilities/Options.h"
#include "Utilities/Util.h"

#include "Distribution/Distribution.h"
#include "ValueDefinitions/RealVariable.h"
#include "Utilities/Timer.h"
#include "Utilities/OpalException.h"
#include "Solvers/ParticleMatterInteractionHandler.hh"
#include "Structure/BoundaryGeometry.h"
#include "AbsBeamline/Monitor.h"

class PartData;

ParallelTTracker::ParallelTTracker(const Beamline &beamline,
                                   const PartData &reference,
                                   bool revBeam,
                                   bool revTrack):
    Tracker(beamline, reference, revBeam, revTrack),
    itsDataSink_m(NULL),
    itsOpalBeamline_m(beamline.getOrigin3D(), beamline.getInitialDirection()),
    globalEOL_m(false),
    wakeStatus_m(false),
    wakeFunction_m(NULL),
    pathLength_m(0.0),
    zstart_m(0.0),
    dtCurrentTrack_m(0.0),
    minStepforReBin_m(-1),
    minBinEmitted_m(std::numeric_limits<size_t>::max()),
    repartFreq_m(-1),
    emissionSteps_m(std::numeric_limits<unsigned int>::max()),
    numParticlesInSimulation_m(0),
    timeIntegrationTimer1_m(IpplTimings::getTimer("TIntegration1")),
    timeIntegrationTimer2_m(IpplTimings::getTimer("TIntegration2")),
    fieldEvaluationTimer_m(IpplTimings::getTimer("External field eval")),
    BinRepartTimer_m(IpplTimings::getTimer("Binaryrepart")),
    WakeFieldTimer_m(IpplTimings::getTimer("WakeField")),
    particleMatterStatus_m(false),
    totalParticlesInSimulation_m(0)
{}

ParallelTTracker::ParallelTTracker(const Beamline &beamline,
                                   PartBunchBase<double, 3> *bunch,
                                   DataSink &ds,
                                   const PartData &reference,
                                   bool revBeam,
                                   bool revTrack,
                                   const std::vector<unsigned long long> &maxSteps,
                                   double zstart,
                                   const std::vector<double> &zstop,
                                   const std::vector<double> &dt):
    Tracker(beamline, bunch, reference, revBeam, revTrack),
    itsDataSink_m(&ds),
    itsOpalBeamline_m(beamline.getOrigin3D(), beamline.getInitialDirection()),
    globalEOL_m(false),
    wakeStatus_m(false),
    wakeFunction_m(NULL),
    pathLength_m(0.0),
    zstart_m(zstart),
    dtCurrentTrack_m(0.0),
    minStepforReBin_m(-1),
    minBinEmitted_m(std::numeric_limits<size_t>::max()),
    repartFreq_m(-1),
    emissionSteps_m(std::numeric_limits<unsigned int>::max()),
    numParticlesInSimulation_m(0),
    timeIntegrationTimer1_m(IpplTimings::getTimer("TIntegration1")),
    timeIntegrationTimer2_m(IpplTimings::getTimer("TIntegration2")),
    fieldEvaluationTimer_m(IpplTimings::getTimer("External field eval")),
    BinRepartTimer_m(IpplTimings::getTimer("Binaryrepart")),
    WakeFieldTimer_m(IpplTimings::getTimer("WakeField")),
    particleMatterStatus_m(false),
    totalParticlesInSimulation_m(0)
{
    for (unsigned int i = 0; i < zstop.size(); ++ i) {
        stepSizes_m.push_back(dt[i], zstop[i], maxSteps[i]);
    }

    stepSizes_m.sortAscendingZStop();
    stepSizes_m.resetIterator();
}

ParallelTTracker::~ParallelTTracker() {}

void ParallelTTracker::visitBeamline(const Beamline &bl) {
    const FlaggedBeamline* fbl = static_cast<const FlaggedBeamline*>(&bl);
    if (fbl->getRelativeFlag()) {
        OpalBeamline stash(fbl->getOrigin3D(), fbl->getInitialDirection());
        stash.swap(itsOpalBeamline_m);
        fbl->iterate(*this, false);
        itsOpalBeamline_m.prepareSections();
        itsOpalBeamline_m.compute3DLattice();
        stash.merge(itsOpalBeamline_m);
        stash.swap(itsOpalBeamline_m);
    } else {
        fbl->iterate(*this, false);
    }
}

void ParallelTTracker::updateRFElement(std::string elName, double maxPhase) {
    FieldList cavities = itsOpalBeamline_m.getElementByType(ElementBase::RFCAVITY);
    FieldList travelingwaves = itsOpalBeamline_m.getElementByType(ElementBase::TRAVELINGWAVE);
    cavities.insert(cavities.end(), travelingwaves.begin(), travelingwaves.end());

    for (FieldList::iterator fit = cavities.begin(); fit != cavities.end(); ++ fit) {
        if ((*fit).getElement()->getName() == elName) {

            RFCavity *element = static_cast<RFCavity *>((*fit).getElement().get());

            element->setPhasem(maxPhase);
            element->setAutophaseVeto();

            INFOMSG("Restored cavity phase from the h5 file. Name: " << element->getName() << ", phase: " << maxPhase << " rad" << endl);
            return;
        }
    }
}

void ParallelTTracker::saveCavityPhases() {
    itsDataSink_m->storeCavityInformation();
}

void ParallelTTracker::restoreCavityPhases() {
    typedef std::vector<MaxPhasesT>::iterator iterator_t;

    if (OpalData::getInstance()->hasPriorTrack() ||
        OpalData::getInstance()->inRestartRun()) {
        iterator_t it = OpalData::getInstance()->getFirstMaxPhases();
        iterator_t end = OpalData::getInstance()->getLastMaxPhases();
        for (; it < end; ++ it) {
            updateRFElement((*it).first, (*it).second);
        }
    }
}

void ParallelTTracker::execute() {
    Inform msg("ParallelTTracker ", *gmsg);
    OpalData::getInstance()->setInPrepState(true);

    BorisPusher pusher(itsReference);
    const double globalTimeShift = itsBunch_m->weHaveEnergyBins()? OpalData::getInstance()->getGlobalPhaseShift(): 0.0;
    OpalData::getInstance()->setGlobalPhaseShift(0.0);

    // the time step needs to be positive in the setup
    itsBunch_m->setdT(std::abs(itsBunch_m->getdT()));
    dtCurrentTrack_m = itsBunch_m->getdT();

    evenlyDistributeParticles();

    if (OpalData::getInstance()->hasPriorTrack() || OpalData::getInstance()->inRestartRun()) {
        OpalData::getInstance()->setOpenMode(OpalData::OPENMODE::APPEND);
    }

    prepareSections();

    double minTimeStep = stepSizes_m.getMinTimeStep();
    unsigned long long totalNumSteps = stepSizes_m.getNumStepsFinestResolution();

    itsOpalBeamline_m.activateElements();

    if ( OpalData::getInstance()->hasPriorTrack() ||
         OpalData::getInstance()->inRestartRun()) {

        pathLength_m = itsBunch_m->get_sPos();
        zstart_m = pathLength_m;

        restoreCavityPhases();
    } else {

        double momentum = euclidean_norm(itsBunch_m->get_pmean_Distribution());
        CoordinateSystemTrafo beamlineToLab = itsOpalBeamline_m.getCSTrafoLab2Local().inverted();
        itsBunch_m->toLabTrafo_m = beamlineToLab;

        itsBunch_m->RefPartR_m = beamlineToLab.transformTo(Vector_t(0.0));
        itsBunch_m->RefPartP_m = beamlineToLab.rotateTo(momentum * Vector_t(0, 0, 1));

        if (itsBunch_m->getTotalNum() > 0) {
            if (!itsOpalBeamline_m.containsSource()) {
                momentum = itsReference.getP() / itsBunch_m->getM();
                itsBunch_m->RefPartP_m = beamlineToLab.rotateTo(momentum * Vector_t(0, 0, 1));
            }

            if (zstart_m > pathLength_m) {
                findStartPosition(pusher);
            }

            itsBunch_m->set_sPos(pathLength_m);
        }
    }

    stepSizes_m.advanceToPos(zstart_m);
    if (back_track) {
        itsBunch_m->setdT(-std::abs(itsBunch_m->getdT()));
        stepSizes_m.reverseDirection();
        if (pathLength_m < stepSizes_m.getZStop()) {
            ++ stepSizes_m;
        }
    }

    Vector_t rmin(0.0), rmax(0.0);
    if (itsBunch_m->getTotalNum() > 0) {
        itsBunch_m->get_bounds(rmin, rmax);
    }

    OrbitThreader oth(itsReference,
                      itsBunch_m->RefPartR_m,
                      itsBunch_m->RefPartP_m,
                      pathLength_m,
                      -rmin(2),
                      itsBunch_m->getT(),
                      (back_track? -minTimeStep: minTimeStep),
                      totalNumSteps,
                      stepSizes_m.getFinalZStop() + 2 * rmax(2),
                      itsOpalBeamline_m);

    oth.execute();

    saveCavityPhases();

    numParticlesInSimulation_m = itsBunch_m->getTotalNum();
    totalParticlesInSimulation_m = itsBunch_m->getTotalNum();

    setTime();

    double time = itsBunch_m->getT() - globalTimeShift;
    itsBunch_m->setT(time);

    *gmsg << level1 << *itsBunch_m << endl;

    unsigned long long step = itsBunch_m->getGlobalTrackStep();
    OPALTimer::Timer myt1;
    *gmsg << "Track start at: " << myt1.time() << ", t= " << Util::getTimeString(time) << "; "
          << "zstart at: " << Util::getLengthString(pathLength_m)
          << endl;

    prepareEmission();

    *gmsg << level1
          << "Executing ParallelTTracker, initial dt= " << Util::getTimeString(itsBunch_m->getdT()) << ";\n"
          << "max integration steps " << stepSizes_m.getMaxSteps() << ", next step= " << step << endl;

    setOptionalVariables();

    globalEOL_m = false;
    wakeStatus_m = false;
    deletedParticles_m = false;
    OpalData::getInstance()->setInPrepState(false);
    while (!stepSizes_m.reachedEnd()) {
        unsigned long long trackSteps = stepSizes_m.getNumSteps() + step;
        dtCurrentTrack_m = stepSizes_m.getdT();
        changeDT(back_track);

        for (; step < trackSteps; ++ step) {
            Vector_t rmin(0.0), rmax(0.0);
            if (itsBunch_m->getTotalNum() > 0) {
                itsBunch_m->get_bounds(rmin, rmax);
            }

            timeIntegration1(pusher);

            itsBunch_m->Ef = Vector_t(0.0);
            itsBunch_m->Bf = Vector_t(0.0);

            computeSpaceChargeFields(step);

            selectDT(back_track);
            emitParticles(step);
            selectDT(back_track);

            computeExternalFields(oth);

            timeIntegration2(pusher);

            itsBunch_m->incrementT();

            if (itsBunch_m->getT() > 0.0 ||
                itsBunch_m->getdT() < 0.0) {
                updateReference(pusher);
            }

            if (deletedParticles_m) {
                evenlyDistributeParticles();
                deletedParticles_m = false;
            }
            itsBunch_m->set_sPos(pathLength_m);

            if (hasEndOfLineReached()) break;

            bool const psDump = ((itsBunch_m->getGlobalTrackStep() % Options::psDumpFreq) + 1 == Options::psDumpFreq);
            bool const statDump = ((itsBunch_m->getGlobalTrackStep() % Options::statDumpFreq) + 1 == Options::statDumpFreq);
            dumpStats(step, psDump, statDump);

            itsBunch_m->incTrackSteps();

            double beta = euclidean_norm(itsBunch_m->RefPartP_m / Util::getGamma(itsBunch_m->RefPartP_m));
            double driftPerTimeStep = std::abs(itsBunch_m->getdT()) * Physics::c * beta;
            if (std::abs(stepSizes_m.getZStop() - pathLength_m) < 0.5 * driftPerTimeStep) {
                break;
            }
        }

        if (globalEOL_m)
            break;

        ++ stepSizes_m;
    }

    itsBunch_m->set_sPos(pathLength_m);

    if (numParticlesInSimulation_m > minBinEmitted_m) {
        numParticlesInSimulation_m = itsBunch_m->getTotalNum();
    }

    bool const psDump = (((itsBunch_m->getGlobalTrackStep() - 1) % Options::psDumpFreq) + 1 != Options::psDumpFreq);
    bool const statDump = (((itsBunch_m->getGlobalTrackStep() - 1) % Options::statDumpFreq) + 1 != Options::statDumpFreq);
    writePhaseSpace((step + 1), psDump, statDump);

    msg << level2 << "Dump phase space of last step" << endl;

    itsOpalBeamline_m.switchElementsOff();

    OPALTimer::Timer myt3;
    *gmsg << "done executing ParallelTTracker at " << myt3.time() << endl;

    Monitor::writeStatistics();

    OpalData::getInstance()->setPriorTrack();
}

void ParallelTTracker::prepareSections() {

    itsBeamline_m.accept(*this);
    itsOpalBeamline_m.prepareSections();

    itsOpalBeamline_m.compute3DLattice();
    itsOpalBeamline_m.save3DLattice();
    itsOpalBeamline_m.save3DInput();
}

void ParallelTTracker::timeIntegration1(BorisPusher & pusher) {

    IpplTimings::startTimer(timeIntegrationTimer1_m);
    pushParticles(pusher);
    IpplTimings::stopTimer(timeIntegrationTimer1_m);
}


void ParallelTTracker::timeIntegration2(BorisPusher & pusher) {
    /*
      transport and emit particles
      that passed the cathode in the first
      half-step or that would pass it in the
      second half-step.

      to make IPPL and the field solver happy
      make sure that at least 10 particles are emitted

      also remember that node 0 has
      all the particles to be emitted

      this has to be done *after* the calculation of the
      space charges! thereby we neglect space charge effects
      in the very first step of a new-born particle.

    */

    IpplTimings::startTimer(timeIntegrationTimer2_m);
    kickParticles(pusher);
    //switchElements();
    pushParticles(pusher);

    const unsigned int localNum = itsBunch_m->getLocalNum();
    for (unsigned int i = 0; i < localNum; ++ i) {
        itsBunch_m->dt[i] = itsBunch_m->getdT();
    }

    IpplTimings::stopTimer(timeIntegrationTimer2_m);
}

void ParallelTTracker::selectDT(bool backTrack) {

    if (itsBunch_m->getIfBeamEmitting()) {
        double dt = itsBunch_m->getEmissionDeltaT();
        itsBunch_m->setdT(dt);
    } else {
        double dt = dtCurrentTrack_m;
        itsBunch_m->setdT(dt);
    }
    if (backTrack) {
        itsBunch_m->setdT(-std::abs(itsBunch_m->getdT()));
    }
}

void ParallelTTracker::changeDT(bool backTrack) {
    selectDT(backTrack);
    const unsigned int localNum = itsBunch_m->getLocalNum();
    for (unsigned int i = 0; i < localNum; ++ i) {
        itsBunch_m->dt[i] = itsBunch_m->getdT();
    }
}

void ParallelTTracker::emitParticles(long long step) {
    if (!itsBunch_m->weHaveEnergyBins()) return;

    if (itsBunch_m->getIfBeamEmitting()) {
        CoordinateSystemTrafo gunToLab = itsOpalBeamline_m.getCSTrafoLab2Local().inverted();
        CoordinateSystemTrafo refToGun = itsOpalBeamline_m.getCSTrafoLab2Local() * itsBunch_m->toLabTrafo_m;

        transformBunch(refToGun);

        itsBunch_m->switchToUnitlessPositions(true);

        Vector_t externalE = Vector_t(0.0);
        Vector_t externalB = Vector_t(0.0);
        itsOpalBeamline_m.getFieldAt(gunToLab.transformTo(Vector_t(0.0)),
                                     gunToLab.rotateTo(Vector_t(0.0)),
                                     itsBunch_m->getT() + 0.5 * itsBunch_m->getdT(),
                                     externalE,
                                     externalB);
        itsBunch_m->emitParticles(externalE(2));

        itsBunch_m->updateNumTotal();
        numParticlesInSimulation_m = itsBunch_m->getTotalNum();
        itsBunch_m->switchOffUnitlessPositions(true);

        transformBunch(refToGun.inverted());
    }

    if (step > minStepforReBin_m) {
        itsBunch_m->Rebin();
        itsBunch_m->resetInterpolationCache(true);
    }
}


void ParallelTTracker::computeSpaceChargeFields(unsigned long long step) {
    if (numParticlesInSimulation_m <= minBinEmitted_m) return;

    if (!itsBunch_m->hasFieldSolver()) return;

    itsBunch_m->calcBeamParameters();
    Quaternion alignment = getQuaternion(itsBunch_m->get_pmean(), Vector_t(0, 0, 1));
    CoordinateSystemTrafo beamToReferenceCSTrafo(Vector_t(0, 0, pathLength_m), alignment.conjugate());
    CoordinateSystemTrafo referenceToBeamCSTrafo = beamToReferenceCSTrafo.inverted();

    const unsigned int localNum1 = itsBunch_m->getLocalNum();
    for (unsigned int i = 0; i < localNum1; ++ i) {
        itsBunch_m->R[i] = referenceToBeamCSTrafo.transformTo(itsBunch_m->R[i]);
    }

    itsBunch_m->boundp();

    if (step % repartFreq_m + 1 == repartFreq_m) {
        doBinaryRepartition();
    }

    if (itsBunch_m->weHaveEnergyBins()) {
        itsBunch_m->calcGammas();
        itsBunch_m->resetInterpolationCache();
        ParticleAttrib<double> Q_back = itsBunch_m->Q;
        for (int binNumber = 0; binNumber < itsBunch_m->getLastEmittedEnergyBin() &&
                 binNumber < itsBunch_m->getNumberOfEnergyBins(); ++binNumber) {

            itsBunch_m->setBinCharge(binNumber);
            itsBunch_m->setGlobalMeanR(itsBunch_m->get_centroid());
            itsBunch_m->computeSelfFields(binNumber);
            itsBunch_m->Q = Q_back;

        }

    } else {
        itsBunch_m->setGlobalMeanR(itsBunch_m->get_centroid());
        itsBunch_m->computeSelfFields();
    }

    const unsigned int localNum2 = itsBunch_m->getLocalNum();
    for (unsigned int i = 0; i < localNum2; ++ i) {
        itsBunch_m->R[i] = beamToReferenceCSTrafo.transformTo(itsBunch_m->R[i]);
        itsBunch_m->Ef[i] = beamToReferenceCSTrafo.rotateTo(itsBunch_m->Ef[i]);
        itsBunch_m->Bf[i] = beamToReferenceCSTrafo.rotateTo(itsBunch_m->Bf[i]);
    }
}


void ParallelTTracker::computeExternalFields(OrbitThreader &oth) {
    IpplTimings::startTimer(fieldEvaluationTimer_m);
    Inform msg("ParallelTTracker ", *gmsg);
    const unsigned int localNum = itsBunch_m->getLocalNum();
    bool locPartOutOfBounds = false, globPartOutOfBounds = false;
    Vector_t rmin(0.0), rmax(0.0);
    if (itsBunch_m->getTotalNum() > 0)
        itsBunch_m->get_bounds(rmin, rmax);
    IndexMap::value_t elements;

    try {
        elements = oth.query(pathLength_m + 0.5 * (rmax(2) + rmin(2)), rmax(2) - rmin(2));
    } catch(IndexMap::OutOfBounds &e) {
        globalEOL_m = true;
        return;
    }

    IndexMap::value_t::const_iterator it = elements.begin();
    const IndexMap::value_t::const_iterator end = elements.end();

    for (; it != end; ++ it) {
        CoordinateSystemTrafo refToLocalCSTrafo = (itsOpalBeamline_m.getMisalignment((*it)) *
                                                   (itsOpalBeamline_m.getCSTrafoLab2Local((*it)) * itsBunch_m->toLabTrafo_m));
        CoordinateSystemTrafo localToRefCSTrafo = refToLocalCSTrafo.inverted();

        (*it)->setCurrentSCoordinate(pathLength_m + rmin(2));

        for (unsigned int i = 0; i < localNum; ++ i) {
            if (itsBunch_m->Bin[i] < 0) continue;

            itsBunch_m->R[i] = refToLocalCSTrafo.transformTo(itsBunch_m->R[i]);
            itsBunch_m->P[i] = refToLocalCSTrafo.rotateTo(itsBunch_m->P[i]);
            double &dt = itsBunch_m->dt[i];

            Vector_t localE(0.0), localB(0.0);

            if ((*it)->apply(i, itsBunch_m->getT() + 0.5 * dt, localE, localB)) {
                itsBunch_m->R[i] = localToRefCSTrafo.transformTo(itsBunch_m->R[i]);
                itsBunch_m->P[i] = localToRefCSTrafo.rotateTo(itsBunch_m->P[i]);
                itsBunch_m->Bin[i] = -1;
                locPartOutOfBounds = true;

                continue;
            }

            itsBunch_m->R[i] = localToRefCSTrafo.transformTo(itsBunch_m->R[i]);
            itsBunch_m->P[i] = localToRefCSTrafo.rotateTo(itsBunch_m->P[i]);
            itsBunch_m->Ef[i] += localToRefCSTrafo.rotateTo(localE);
            itsBunch_m->Bf[i] += localToRefCSTrafo.rotateTo(localB);
        }
    }

    IpplTimings::stopTimer(fieldEvaluationTimer_m);

    computeWakefield(elements);
    computeParticleMatterInteraction(elements, oth);

    reduce(locPartOutOfBounds, globPartOutOfBounds, OpOrAssign());

    size_t ne = 0;
    if (globPartOutOfBounds) {
        if (itsBunch_m->hasFieldSolver()) {
            ne = itsBunch_m->boundp_destroyT();
        } else {
            ne = itsBunch_m->destroyT();
        }
        numParticlesInSimulation_m  = itsBunch_m->getTotalNum();
        totalParticlesInSimulation_m -= ne;
        deletedParticles_m = true;
    }

    size_t totalNum = itsBunch_m->getTotalNum();
    if (numParticlesInSimulation_m > minBinEmitted_m || totalNum > minBinEmitted_m) {
        numParticlesInSimulation_m = totalNum;
    }

    if (ne > 0) {
        msg << level1 << "* Deleted " << ne << " particles, "
            << "remaining " << totalParticlesInSimulation_m << " particles" << endl;
    }
}

void ParallelTTracker::computeWakefield(IndexMap::value_t &elements) {
    bool hasWake = false;
    WakeFunction *wfInstance;

    Inform msg("ParallelTTracker ", *gmsg);

    const unsigned int localNum = itsBunch_m->getLocalNum();

    IndexMap::value_t::const_iterator it = elements.begin();
    const IndexMap::value_t::const_iterator end = elements.end();

    for (; it != end; ++ it) {
        if ((*it)->hasWake() && !hasWake) {
            IpplTimings::startTimer(WakeFieldTimer_m);

            hasWake = true;

            if ((*it)->getWake()->getType() == "CSRWakeFunction" ||
                (*it)->getWake()->getType() == "CSRIGFWakeFunction") {
                if ((*it)->getType() == ElementBase::RBEND ||
                    (*it)->getType() == ElementBase::SBEND) {
                    wfInstance = (*it)->getWake();
                    wakeFunction_m = wfInstance;
                } else {
                    wfInstance = wakeFunction_m;
                }
            } else {
                wfInstance = (*it)->getWake();
            }

            if (!wfInstance) {
                throw OpalException("ParallelTTracker::computeWakefield",
                                    "empty wake function");
            }

            if (!wakeStatus_m) {
                msg << level2 << "============== START WAKE CALCULATION =============" << endl;
                wfInstance->initialize((*it).get());
                wakeStatus_m = true;
            }

            if (!itsBunch_m->hasFieldSolver()) itsBunch_m->calcBeamParameters();

            Quaternion alignment = getQuaternion(itsBunch_m->get_pmean(), Vector_t(0, 0, 1));
            CoordinateSystemTrafo referenceToBeamCSTrafo(Vector_t(0.0), alignment);
            CoordinateSystemTrafo beamToReferenceCSTrafo = referenceToBeamCSTrafo.inverted();

            for (unsigned int i = 0; i < localNum; ++ i) {
                itsBunch_m->R[i] = referenceToBeamCSTrafo.transformTo(itsBunch_m->R[i]);
                itsBunch_m->P[i] = referenceToBeamCSTrafo.rotateTo(itsBunch_m->P[i]);
                itsBunch_m->Ef[i] = referenceToBeamCSTrafo.rotateTo(itsBunch_m->Ef[i]);
            }

            wfInstance->apply(itsBunch_m);

            for (unsigned int i = 0; i < localNum; ++ i) {
                itsBunch_m->R[i] = beamToReferenceCSTrafo.transformTo(itsBunch_m->R[i]);
                itsBunch_m->P[i] = beamToReferenceCSTrafo.rotateTo(itsBunch_m->P[i]);
                itsBunch_m->Ef[i] = beamToReferenceCSTrafo.rotateTo(itsBunch_m->Ef[i]);
            }

            IpplTimings::stopTimer(WakeFieldTimer_m);
        }
    }

    if (wakeStatus_m && !hasWake) {
        msg << level2 << "=============== END WAKE CALCULATION ==============" << endl;
        wakeStatus_m = false;
    }
}

void ParallelTTracker::computeParticleMatterInteraction(IndexMap::value_t elements, OrbitThreader &oth) {
    Inform msg("ParallelTTracker ", *gmsg);
    std::set<IndexMap::value_t::value_type> elementsWithParticleMatterInteraction;
    std::set<ParticleMatterInteractionHandler*> particleMatterinteractionHandlers;
    std::pair<double, double> currentRange(0.0, 0.0);

    while (elements.size() > 0) {
        auto it = elements.begin();
        if ((*it)->hasParticleMatterInteraction()) {
            elementsWithParticleMatterInteraction.insert(*it);
            particleMatterinteractionHandlers.insert((*it)->getParticleMatterInteraction());

            std::pair<double, double> range = oth.getRange(*it, pathLength_m);
            currentRange.first = std::min(currentRange.first, range.first);
            currentRange.second = std::max(currentRange.second, range.second);

            IndexMap::value_t touching = oth.getTouchingElements(range);
            elements.insert(touching.begin(), touching.end());
        }

        elements.erase(it);
    }

    if (elementsWithParticleMatterInteraction.size() > 0) {
        std::set<ParticleMatterInteractionHandler*> oldSPHandlers;
        std::vector<ParticleMatterInteractionHandler*> leftBehindSPHandlers, newSPHandlers;
        for (auto it: activeParticleMatterInteractionHandlers_m) {
            oldSPHandlers.insert(it);
        }

        leftBehindSPHandlers.resize(std::max(oldSPHandlers.size(),
                                             particleMatterinteractionHandlers.size()));
        auto last = std::set_difference(oldSPHandlers.begin(), oldSPHandlers.end(),
                                        particleMatterinteractionHandlers.begin(), particleMatterinteractionHandlers.end(),
                                        leftBehindSPHandlers.begin());
        leftBehindSPHandlers.resize(last - leftBehindSPHandlers.begin());

        for (auto it: leftBehindSPHandlers) {
            if (!it->stillActive()) {
                activeParticleMatterInteractionHandlers_m.erase(it);
            }
        }

        newSPHandlers.resize(std::max(oldSPHandlers.size(),
                                      elementsWithParticleMatterInteraction.size()));
        last = std::set_difference(particleMatterinteractionHandlers.begin(), particleMatterinteractionHandlers.end(),
                                   oldSPHandlers.begin(), oldSPHandlers.end(),
                                   newSPHandlers.begin());
        newSPHandlers.resize(last - newSPHandlers.begin());

        for (auto it: newSPHandlers) {
            activeParticleMatterInteractionHandlers_m.insert(it);
        }

        if(!particleMatterStatus_m) {
            msg << level2 << "============== START PARTICLE MATTER INTERACTION CALCULATION =============" << endl;
            particleMatterStatus_m = true;
        }
    }

    if (particleMatterStatus_m) {
        do {
            ///all particles in material if max per node is 2 and other degraders have 0 particles
            //check if more than one degrader has particles
            ParticleMatterInteractionHandler* onlyDegraderWithParticles = NULL;
            int degradersWithParticlesCount = 0;
            for (auto it: activeParticleMatterInteractionHandlers_m) {
                it->setFlagAllParticlesIn(false);
                if (it->getParticlesInMat() > 0) {
                    onlyDegraderWithParticles = it;
                    ++ degradersWithParticlesCount;
                }
            }

            //if max particles per node is 2, and only one degrader has particles set
            //AllParticlesIn for this degrader to true
            unsigned int localNum = itsBunch_m->getLocalNum();
            unsigned int totalNum = 0;
            reduce(localNum, totalNum, OpAddAssign());
            bool allParticlesInMat = (totalNum == 0 &&
                                      degradersWithParticlesCount == 1);

            if (allParticlesInMat) {
                onlyDegraderWithParticles->setFlagAllParticlesIn(true);
                msg << "All particles in degrader" << endl;
            }

            auto boundingSphere = itsBunch_m->getLocalBoundingSphere();
            unsigned int rediffusedParticles = 0;
            unsigned int numEnteredParticles = 0;
            for (auto it: activeParticleMatterInteractionHandlers_m) {
                ElementBase* element = it->