def init_fields(sim, w, ctau, k0, z0, zf, E0, m=1):
"""
Imprints the appropriate profile on the fields of the simulation.
Parameters
----------
sim: Simulation object from fbpic
w : float
The initial waist of the laser (in microns)
ctau : float
The initial temporal waist of the laser (in microns)
k0 : flat
The central wavevector of the laser (in microns^-1)
z0 : float
The position of the centroid on the z axis
zf : float
The position of the focal plane
E0 : float
The initial E0 of the pulse
m: int, optional
The mode on which to imprint the profile
For m = 1 : gaussian profile, linearly polarized beam
For m = 0 : annular profile, polarized in E_theta
"""
# Initialize the fields with the right value and phase
if m == 1:
add_laser(sim,
E0 * e / (m_e * c**2 * k0),
w,
ctau,
z0,
zf=zf,
lambda0=2 * np.pi / k0)
if m == 0:
fld = sim.fld
z = fld.interp[m].z
r = fld.interp[m].r
profile = annular_pulse(z, r, w, ctau, k0, z0, E0)
fld.interp[m].Et[:, :] = profile
fld.interp[m].Br[:, :] = -1. / c * profile
m_e,
bunch_gamma,
bunch_n,
bunch_zmin,
bunch_zmax,
0,
bunch_rmax,
boost=boost)
if track_bunch:
bunch.track(sim.comm)
# Add a laser to the fields of the simulation
add_laser(sim,
a0,
w0,
ctau,
z0,
lambda0=lambda0,
zf=zfoc,
gamma_boost=boost.gamma0)
# Convert parameter to boosted frame
v_window_boosted, = boost.velocity([v_window])
# Configure the moving window
sim.set_moving_window(v=v_window_boosted)
# Add a field diagnostic
sim.diags = [
# Diagnostics in the boosted frame
FieldDiagnostic(dt_period=dt_boosted_diag_period,
fldobject=sim.fld,
comm=sim.comm),
def run_and_check_laser_antenna(gamma_b,
show,
write_files,
z0,
v=0,
forward_propagating=True):
"""
Generic function, which runs and check the laser antenna for
both boosted frame and lab frame
Parameters
----------
gamma_b: float or None
The Lorentz factor of the boosted frame
show: bool
Whether to show the images of the laser as pop-up windows
write_files: bool
Whether to output openPMD data of the laser
v: float (m/s)
Speed of the laser antenna
"""
# Initialize the simulation object
sim = Simulation(Nz,
zmax,
Nr,
rmax,
Nm,
dt,
p_zmin=0,
p_zmax=0,
p_rmin=0,
p_rmax=0,
p_nz=2,
p_nr=2,
p_nt=2,
n_e=0.,
zmin=zmin,
use_cuda=use_cuda,
boundaries='open',
gamma_boost=gamma_b)
# Remove the particles
sim.ptcl = []
# Add the laser
add_laser(sim,
a0,
w0,
ctau,
z0,
zf=zf,
method='antenna',
z0_antenna=z0_antenna,
v_antenna=v,
gamma_boost=gamma_b,
fw_propagating=forward_propagating)
# Calculate the number of steps between each output
N_step = int(round(Ntot_step / N_show))
# Add diagnostic
if write_files:
sim.diags = [
FieldDiagnostic(N_step,
sim.fld,
comm=None,
fieldtypes=["rho", "E", "B", "J"])
]
# Loop over the iterations
print('Running the simulation...')
for it in range(N_show):
print('Diagnostic point %d/%d' % (it, N_show))
# Advance the Maxwell equations
sim.step(N_step, show_progress=False)
# Plot the fields during the simulation
if show == True:
show_fields(sim.fld.interp[1], 'Er')
# Finish the remaining iterations
sim.step(Ntot_step - N_show * N_step, show_progress=False)
# Check the transverse E and B field
Nz_half = int(sim.fld.interp[1].Nz / 2) + 2
z = sim.fld.interp[1].z[Nz_half:-(sim.comm.n_guard+sim.comm.n_damp+\
sim.comm.n_inject)]
r = sim.fld.interp[1].r
# Loop through the different fields
for fieldtype, info_in_real_part, factor in [ ('Er', True, 2.), \
('Et', False, 2.), ('Br', False, 2.*c), ('Bt', True, 2.*c) ]:
# factor correspond to the factor that has to be applied
# in order to get a value which is comparable to an electric field
# (Because of the definition of the interpolation grid, the )
field = getattr(sim.fld.interp[1], fieldtype)\
[Nz_half:-(sim.comm.n_guard+sim.comm.n_damp+\
sim.comm.n_inject)]
print('Checking %s' % fieldtype)
check_fields(factor * field, z, r, info_in_real_part, z0, gamma_b,
forward_propagating)
print('OK')
p_nr=p_nr,
p_nt=p_nt,
p_zmin=p_zmin)
# Activate ionization of He ions (for levels above 1).
# Store the created electrons in the species `elec`
atoms_He.make_ionizable('He', target_species=elec, level_start=1)
# Activate ionization of N ions (for levels above 5).
# Store the created electrons in a new dedicated electron species that
# does not contain any macroparticles initially
elec_from_N = sim.add_new_species(q=-e, m=m_e)
atoms_N.make_ionizable('N', target_species=elec_from_N, level_start=5)
# Add a laser to the fields of the simulation
add_laser(sim, a0, w0, ctau, z0, zf=z_foc)
if use_restart is False:
# Track electrons if required (species 0 correspond to the electrons)
if track_electrons:
elec.track(sim.comm)
else:
# Load the fields and particles from the latest checkpoint file
restart_from_checkpoint(sim)
# Configure the moving window
sim.set_moving_window(v=v_window)
# Add diagnostics
sim.diags = [
FieldDiagnostic(diag_period, sim.fld, comm=sim.comm),
p_zmax,
p_rmin,
p_rmax,
p_nz,
p_nr,
p_nt,
n_e,
dens_func=dens_func,
zmin=zmin,
boundaries='open',
n_order=n_order,
use_cuda=use_cuda)
# Load initial fields
# Add a laser to the fields of the simulation
add_laser(sim, a0, w0, ctau, z0)
if use_restart is False:
# Track electrons if required (species 0 correspond to the electrons)
if track_electrons:
sim.ptcl[0].track(sim.comm)
else:
# Load the fields and particles from the latest checkpoint file
restart_from_checkpoint(sim)
# Configure the moving window
sim.set_moving_window(v=v_window)
# Add diagnostics
sim.diags = [
FieldDiagnostic(diag_period, sim.fld, comm=sim.comm),
# Create the plasma electrons
elec = sim.add_new_species(q=-e,
m=m_e,
n=n_e,
dens_func=dens_func,
p_zmin=p_zmin,
p_zmax=p_zmax,
p_rmax=p_rmax,
p_nz=p_nz,
p_nr=p_nr,
p_nt=p_nt)
# Load initial fields
# Add a laser to the fields of the simulation
add_laser(sim, a0, w0, ctau, z0, lambda0=lambda0, zf=zfoc)
if use_restart is False:
# Track electrons if required (species 0 correspond to the electrons)
if track_electrons:
elec.track(sim.comm)
else:
# Load the fields and particles from the latest checkpoint file
restart_from_checkpoint(sim)
# Configure the moving window
sim.set_moving_window(v=v_window)
# Add diagnostics
sim.diags = [
FieldDiagnostic(dt_period / sim.dt, sim.fld, comm=sim.comm),
