Evaluating moments from particle distribution for the output (* details below)
Abstraction for the output fields
Minor reformatting
(*) Users can now provide [output] fields = [..., ...] parameter in the input with the desired fields to be written at runtime.
Regular field components are addressed as Ex, Bz, Jy etc. To output all 3 components of the given field add Ei (where the code will automatically assume i=1,2,3 for E-field).
Rho and N stand for the mass and the number densities. T stands for the energy-stress tensor, which should be followed by two component identifiers. For instance, T01 or T0x or Ttx stands for the momentum flux in the x-direction. T0i will be automatically unraveled into 3 components with i=1,2,3. Tij will be unraveled into 6 independent components of the spatial part of the energy-momentum tensor i=1,2,3; i<j<=3. Tii will be interpreted as only the diagonal components, i.e., T11, T22, T33. One may also provide only the particular components, e.g., T23, T11, etc.
All the particle-based moments (densities, and the energy-stress tensor) will be computed by default using the distributions of all massive particles. If needed, one can specify the particular species for which to compute Rho, N and/or T separately. Simply pad the definition by the species indices, separated by the underscore _. For example, T03_2_4 computes the z-direction momentum flux for species 2 and 4, Tij_1 computes the stress-energy tensor components for the species 1.
Usage example
Assume the simulation has 4 species (electrons/positrons + ions + photons) and we want to output all the B-field components, the Ez, the pair density, the photon density, the total pressure-tensor of the plasma, and the photon momentum flux in all directions. Our input file might look something like this.
(*) Users can now provide
[output] fields = [..., ...]parameter in the input with the desired fields to be written at runtime.Regular field components are addressed as
Ex,Bz,Jyetc. To output all 3 components of the given field addEi(where the code will automatically assumei=1,2,3for E-field).RhoandNstand for the mass and the number densities.Tstands for the energy-stress tensor, which should be followed by two component identifiers. For instance,T01orT0xorTtxstands for the momentum flux in the x-direction.T0iwill be automatically unraveled into 3 components withi=1,2,3.Tijwill be unraveled into 6 independent components of the spatial part of the energy-momentum tensori=1,2,3; i<j<=3.Tiiwill be interpreted as only the diagonal components, i.e.,T11, T22, T33. One may also provide only the particular components, e.g.,T23,T11, etc.All the particle-based moments (densities, and the energy-stress tensor) will be computed by default using the distributions of all massive particles. If needed, one can specify the particular species for which to compute
Rho,Nand/orTseparately. Simply pad the definition by the species indices, separated by the underscore_. For example,T03_2_4computes the z-direction momentum flux for species 2 and 4,Tij_1computes the stress-energy tensor components for the species 1.Usage example
Assume the simulation has 4 species (electrons/positrons + ions + photons) and we want to output all the B-field components, the Ez, the pair density, the photon density, the total pressure-tensor of the plasma, and the photon momentum flux in all directions. Our input file might look something like this.