Gaussian Beam
This example initializes a Gaussian beam distribution.
Run
This example can be run either as:
Python script:
python3 PICMI_inputs_gaussian_beam.py
orWarpX executable using an input file: (TODO)
For MPI-parallel runs, prefix these lines with mpiexec -n 4 ...
or srun -n 4 ...
, depending on the system.
#!/usr/bin/env python3
#from warp import picmi
import argparse
from pywarpx import picmi
parser = argparse.ArgumentParser(description="Gaussian beam PICMI example")
parser.add_argument('--diagformat', type=str,
help='Format of the full diagnostics (plotfile, openpmd, ascent, sensei, ...)',
default='plotfile')
parser.add_argument('--fields_to_plot', type=str,
help='List of fields to write to diagnostics',
default=['E', 'B', 'J', 'part_per_cell'],
nargs = '*')
args = parser.parse_args()
constants = picmi.constants
nx = 32
ny = 32
nz = 32
xmin = -2.
xmax = +2.
ymin = -2.
ymax = +2.
zmin = -2.
zmax = +2.
number_sim_particles = 32768
total_charge = 8.010883097437485e-07
beam_rms_size = 0.25
electron_beam_divergence = -0.04*constants.c
em_order = 3
grid = picmi.Cartesian3DGrid(number_of_cells = [nx, ny, nz],
lower_bound = [xmin, ymin, zmin],
upper_bound = [xmax, ymax, zmax],
lower_boundary_conditions = ['periodic', 'periodic', 'open'],
upper_boundary_conditions = ['periodic', 'periodic', 'open'],
lower_boundary_conditions_particles = ['periodic', 'periodic', 'absorbing'],
upper_boundary_conditions_particles = ['periodic', 'periodic', 'absorbing'],
warpx_max_grid_size=16)
solver = picmi.ElectromagneticSolver(grid = grid,
cfl = 1.,
stencil_order=[em_order,em_order,em_order])
electron_beam = picmi.GaussianBunchDistribution(n_physical_particles = total_charge/constants.q_e,
rms_bunch_size = [beam_rms_size, beam_rms_size, beam_rms_size],
velocity_divergence = [electron_beam_divergence, electron_beam_divergence, electron_beam_divergence])
proton_beam = picmi.GaussianBunchDistribution(n_physical_particles = total_charge/constants.q_e,
rms_bunch_size = [beam_rms_size, beam_rms_size, beam_rms_size])
electrons = picmi.Species(particle_type='electron', name='electrons', initial_distribution=electron_beam)
protons = picmi.Species(particle_type='proton', name='protons', initial_distribution=proton_beam)
field_diag1 = picmi.FieldDiagnostic(name = 'diag1',
grid = grid,
period = 10,
data_list = args.fields_to_plot,
warpx_format = args.diagformat,
write_dir = '.',
warpx_file_prefix = 'Python_gaussian_beam_plt')
part_diag1 = picmi.ParticleDiagnostic(name = 'diag1',
period = 10,
species = [electrons, protons],
data_list = ['weighting', 'momentum'],
warpx_format = args.diagformat)
sim = picmi.Simulation(solver = solver,
max_steps = 10,
verbose = 1,
warpx_current_deposition_algo = 'direct',
warpx_use_filter = 0)
sim.add_species(electrons, layout=picmi.PseudoRandomLayout(n_macroparticles=number_sim_particles))
sim.add_species(protons, layout=picmi.PseudoRandomLayout(n_macroparticles=number_sim_particles))
sim.add_diagnostic(field_diag1)
sim.add_diagnostic(part_diag1)
# write_inputs will create an inputs file that can be used to run
# with the compiled version.
#sim.write_input_file(file_name = 'inputs_from_PICMI')
# Alternatively, sim.step will run WarpX, controlling it from Python
sim.step()
Note
TODO: This input file should be created following the PICMI_inputs_gaussian_beam.py
file.
Analyze
Note
This section is TODO.
Visualize
Note
This section is TODO.