DINLINE uint32_t numNewParticles(T_Acc const & acc, FrameType& ionFrame, int localIdx)
{
/* alias for the single macro-particle */
auto particle = ionFrame[localIdx];
/* particle position, used for field-to-particle interpolation */
floatD_X pos = particle[position_];
const int particleCellIdx = particle[localCellIdx_];
/* multi-dim coordinate of the local cell inside the super cell */
DataSpace<TVec::dim> localCell(DataSpaceOperations<TVec::dim>::template map<TVec > (particleCellIdx));
/* interpolation of E- */
const picongpu::traits::FieldPosition<typename fields::Solver::NummericalCellType, FieldE> fieldPosE;
ValueType_E eField = Field2ParticleInterpolation()
(cachedE.shift(localCell).toCursor(), pos, fieldPosE());
/* and B-field on the particle position */
const picongpu::traits::FieldPosition<typename fields::Solver::NummericalCellType, FieldB> fieldPosB;
ValueType_B bField = Field2ParticleInterpolation()
(cachedB.shift(localCell).toCursor(), pos, fieldPosB());
/* define number of bound macro electrons before ionization */
float_X prevBoundElectrons = particle[boundElectrons_];
IonizationAlgorithm ionizeAlgo;
/* determine number of new macro electrons to be created */
uint32_t newMacroElectrons = ionizeAlgo(
bField, eField,
particle, this->randomGen(acc)
);
return newMacroElectrons;
}
/** Functor implementation
*
* @param ionFrame reference to frame of the to-be-ionized particles
* @param localIdx local (linear) index in super cell / frame
* @param numNewFreeMacroElectrons reference to variable for each
* thread that stores the number of macro electrons to be
* created during the current time step
*/
DINLINE void operator()(FrameType& ionFrame, int localIdx, unsigned int& numNewFreeMacroElectrons)
{
/* alias for the single macro-particle */
auto particle = ionFrame[localIdx];
/* particle position, used for field-to-particle interpolation */
floatD_X const pos = particle[position_];
int const particleCellIdx = particle[localCellIdx_];
/* multi-dim coordinate of the local cell inside the super cell */
DataSpace<SuperCellSize::dim> localCell(DataSpaceOperations<SuperCellSize::dim>::template map<SuperCellSize > (particleCellIdx));
/* interpolation of density */
const fieldSolver::numericalCellType::traits::FieldPosition<FieldTmp> fieldPosRho;
ValueType_Rho densityV = Field2ParticleInterpolation()
(cachedRho.shift(localCell).toCursor(), pos, fieldPosRho());
/* and energy density field on the particle position */
const fieldSolver::numericalCellType::traits::FieldPosition<FieldTmp> fieldPosEne;
ValueType_Ene kinEnergyV = Field2ParticleInterpolation()
(cachedEne.shift(localCell).toCursor(), pos, fieldPosEne());
/* density in sim units */
float_X const density = densityV[0];
/* energy density in sim units */
float_X const kinEnergyDensity = kinEnergyV[0];
/* Returns the new number of bound electrons for an integer number of macro electrons */
IonizationAlgorithm ionizeAlgo;
numNewFreeMacroElectrons = ionizeAlgo(
kinEnergyDensity,
density,
particle,
this->randomGen()
);
/** ionization of the ion by reducing the number of bound electrons
*
* optimization: only accesses global memory if the charge
* state did really change
*
* @warning substracting a float from a float can potentially
* create a negative boundElectrons number for the ion,
* see #1850 for details
*/
if( numNewFreeMacroElectrons > 0u )
particle[ boundElectrons_ ] -= float_X( numNewFreeMacroElectrons );
}
