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#!/usr/bin/env python3
#
# --- Input file to test particle reflection off an absorbing boundary
import pywarpx
from pywarpx import picmi
constants = picmi.constants
##########################
# numerics parameters
##########################
dt = 7.5e-12
# --- Nb time steps
max_steps = 10
# --- grid
nx = 64
nz = 64
xmin = -125e-6
zmin = -149e-6
xmax = 125e-6
zmax = 1e-6
##########################
# numerics components
##########################
grid = picmi.Cartesian2DGrid(
number_of_cells = [nx, nz],
lower_bound = [xmin, zmin],
upper_bound = [xmax, zmax],
lower_boundary_conditions = ['dirichlet', 'dirichlet'],
upper_boundary_conditions = ['dirichlet', 'dirichlet'],
lower_boundary_conditions_particles = ['open', 'absorbing'],
upper_boundary_conditions_particles = ['open', 'absorbing'],
warpx_max_grid_size = 32
)
solver = picmi.ElectrostaticSolver(
grid=grid, method='Multigrid', required_precision=1e-6,
warpx_self_fields_verbosity=0
)
#embedded_boundary = picmi.EmbeddedBoundary(
# implicit_function="-max(max(x-12.5e-6,-12.5e-6-x),max(z+6.15e-5,-8.65e-5-z))"
#)
##########################
# physics components
##########################
uniform_plasma_elec = picmi.UniformDistribution(
density = 1e15, # number of electrons per m^3
lower_bound = [-1e-5, -1e-5, -125e-6],
upper_bound = [1e-5, 1e-5, -120e-6],
directed_velocity = [0., 0., 5e6] # uth the std of the (unitless) momentum
)
electrons = picmi.Species(
particle_type='electron', name='electrons',
initial_distribution=uniform_plasma_elec,
warpx_save_particles_at_zhi=1,
warpx_save_particles_at_zlo=1,
warpx_reflection_model_zhi="0.5"
)
##########################
# diagnostics
##########################
field_diag = picmi.ParticleDiagnostic(
species=electrons,
name = 'diag1',
data_list=['previous_positions'],
period = 10,
write_dir = '.',
warpx_file_prefix = 'Python_particle_reflection_plt'
)
##########################
# simulation setup
##########################
sim = picmi.Simulation(
solver = solver,
time_step_size = dt,
max_steps = max_steps,
# warpx_embedded_boundary=embedded_boundary,
verbose = 1
)
sim.add_species(
electrons,
layout = picmi.GriddedLayout(
n_macroparticle_per_cell=[5, 2], grid=grid
)
)
sim.add_diagnostic(field_diag)
##########################
# simulation run
##########################
sim.step(max_steps)
################################################
# check that the wrappers to access the particle
# buffer functions as intended
################################################
n = pywarpx.get_particle_boundary_buffer_size("electrons", 'z_hi')
print("Number of electrons in upper buffer:", n)
assert n == 63
n = pywarpx.get_particle_boundary_buffer_size("electrons", 'z_lo')
print("Number of electrons in lower buffer:", n)
assert n == 67
scraped_steps = pywarpx.get_particle_boundary_buffer("electrons", 'z_hi', 'step_scraped', 0)
for arr in scraped_steps:
# print(arr)
assert all(arr == 4)
scraped_steps = pywarpx.get_particle_boundary_buffer("electrons", 'z_lo', 'step_scraped', 0)
for arr in scraped_steps:
# print(arr)
assert all(arr == 8)
|
