Energy Particles plugin: NaNs for photons

[n01r]

If the Energy Particles plugin is activated for photons, one gets nan values after some point.

I have just noticed this but haven't figured out exactly why, yet.

Here some example output of <sim>/simOutput/ph_energy_all.dat. From a 3D sim:

19100 6.842066621241910e-10 6.842066621241910e-10
19200 9.254669290576025e-10 9.254669290576025e-10
19300 1.086544615558932e-09 1.086544615558932e-09
19400 1.331550927268848e-09 1.331550927268848e-09
19500 nan nan
19600 nan nan
19700 nan nan
19800 nan nan

From a 2D sim:

34200 5.834918226123808e-17 5.834918226123808e-17
34300 1.016388305050472e-16 1.016388305050472e-16
34400 1.161795768861727e-16 1.161795768861727e-16
34500 1.235043324595790e-16 1.235043324595790e-16
34600 1.580212274514588e-16 1.580212274514588e-16
34700 nan nan
34800 nan nan
34900 nan nan
35000 nan nan

My production branch is based on commit 2b7bd80eee09d7f6d352d562e1626571879abe71.

[ax3l]

Can you please copy the photon definition in you speciesDefinition.param here?

[n01r]

/*--------------------------- photons ----------------------------------------*/

value_identifier( float_X, MassRatioPhotons, 0.0 );
value_identifier( float_X, ChargeRatioPhotons, 0.0 );

using ParticleFlagsPhotons = bmpl::vector<
    particlePusher< particles::pusher::Photon >,
    shape< UsedParticleShape >,
    interpolation< UsedField2Particle >,
    massRatio< MassRatioPhotons >,
    chargeRatio< ChargeRatioPhotons >,
    exchangeMemCfg< PhotonExchangeMemCfg >
>;

/* define species photons */
using Photons = Particles<
    PMACC_CSTRING( "ph" ),
    ParticleFlagsPhotons,
    DefaultParticleAttributes
>;

The massRatio is given because I remember we once had an offline discussion about that we do not want to assume zero mass when it's not given but we want to explicitly treat zero-mass particles separately.

[ax3l]

How are the photons created? Bremsstrahlung or Synchrotronstrahlung? Looks to me like the Energy Particles is already calculating them correctly but something weird happens to them, e.g. some have no momentum or so... One should dump all photons and verify if some of them have weird looking attribute values (momentum, specifically).

[n01r]

They're created from Bremsstrahlung.

I have photon dumps in my particle dumps as well, so I can have a look at their attributes.