Several TrackParticles diags on one species

[juliencelia]

Hi smilei team!

Hope everyone is fine;)
Just a requested that could be useful : it could be a good idea to allow to define 2 or more TrackParticle diagnostic for the same specie in a same simulation.

Don't know if it is complicated.

Cheers

Julien

[mccoys]

Currently this is not possible because the particle ID has a special behavior in Smilei. If there is a filter in the tracking diagnostic, then particles do not have an initial ID. They only obtain the ID when they pass the filter. This means there is no point having another tracking diagnostic because it cannot create the ID anymore.

To have 2 diagnostics, there are 2 solutions:

• We set all the particle IDs initially, but then we lose the ability to check whether a particle has been filtered already.
• We set 2 different IDs for each particle (one ID for each diagnostic), but that would require a lot of work and memory.

In the end, it is not clear whether this is really helpful to have 2 diagnostics. You could make a clever filter and post-process the data in 2 groups of particles.

[juliencelia]

Thanks Mccoys!
I have to think about that ;)