# Define the grid
grid = initialize_grid()

# Set up the initial conditions for the fields and particles
fields = initialize_fields(grid)
particles = initialize_particles(grid)

# Loop over timesteps
while (time < end_time):
  
  # Advance the particles using the Lorentz force
  particles = push_particles(particles, fields, dt)

  # Update the fields based on the current particle positions and velocities
  fields = solve_fields(fields, particles, dt)

  # Deposit the particle currents onto the grid
  fields = deposit_currents(fields, particles)

  # Interpolate the fields at the particle positions
  fields_at_particles = interpolate_fields(fields, particles)

  # Compute the Lorentz force on the particles
  particles = compute_lorentz_force(particles, fields_at_particles)

  # Increment time
  time += dt