Subject: Re: Current density
To: picongpu-users@hzdr.de
References: <list-16150253@cg2.fz-rossendorf.de>
From: Axel Huebl <a.huebl@hzdr.de>
Organization: HZDR
Message-ID: <3341ec05-9a28-49cc-e0fd-d280f36d492c@hzdr.de>
Date: Fri, 13 Jan 2017 15:41:56 +0100
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In-Reply-To: <list-16150253@cg2.fz-rossendorf.de>
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Dear Danila,

thank you for the question!
PIConGPU in 0.2+ writes HDF5 and ADIOS output in the openPMD format. The
best way to get started is via:

  Introduction: http://openPMD.org
  Full format:  https://github.com/openPMD/openPMD-standard

and then using the files directly. For data set interpretation and
processing you have several options:
  a) investigate the structure just like a file system with tools such as:
     - HDF5Viewer
     - HDFCompass
     - h5py

  b) Use frameworks such as:
     - openPMD-viewer  https://github.com/openPMD/openPMD-viewer
     - postPIC         https://github.com/skuschel/postpic
     - yt-project (develop branch!)  http://yt-project.org/

or more tools, see
  https://github.com/openPMD/openPMD-projects

for a full list.


The current density itself, our field "J", can be dumped directly. Just
add "FieldJ" in the "fileOutput.param" at the following position:


https://github.com/ComputationalRadiationPhysics/picongpu/blob/0.2.1/src/picongpu/include/simulation_defines/param/fileOutput.param#L95-L97

typedef MakeSeq<
    FieldE,
    FieldB,
    FieldJ
>::type NativeFileOutputFields;


Best,
Axel

On 12.01.2017 11:03, Khikhlukha Danila wrote:
> Dear all,
> 
> Currently I'm using PoG version 0.2.1. My simulation finished
> successfully and I'm trying to calculate a current density field in the
> given cross section of the computational grid. 
> 
> However hdf5 files have fields only as follows:
> 
>   * B
>   * E
>   * e_chargeDensity
>   * e_energyDensity
>   * e_particleCounter
>   * e_particleMomentumComponent
> 
> Is there a way how to get current density field? I guess one can try to
> use e_chargeDensity and  e_particleMomentumComponent to calculate it,
> however it is unclear to me which units are used for the momentum field...
> 
> Thank you in advance,
> Danila.
> 
>  
> 

-- 

Axel Huebl
Phone +49 351 260 3582
https://www.hzdr.de/crp
Computational Radiation Physics
Laser Particle Acceleration Division
Helmholtz-Zentrum Dresden - Rossendorf e.V.

Bautzner Landstrasse 400, 01328 Dresden
POB 510119, D-01314 Dresden
Vorstand: Prof. Dr.Dr.h.c. R. Sauerbrey
          Prof. Dr.Dr.h.c. P. Joehnk
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