Initial propagation angle of laser enabled

[huixingjian]

The laser is now allowed to be initialized with a transverse angle on yoz plane by setting laser.init_angle_yz.
The testing input script is

amr.n_cell = 1023 1023 1000
my_constants.L= 4e-4
my_constants.maxstep=200
my_constants.kp = wp/clight
my_constants.wp = sqrt( ne * q_e^2/(m_e *epsilon0) )
my_constants.ne = 1.58e23
my_constants.Plasma_len= 0.00200
my_constants.W0=40e-6

max_step = maxstep
hipace.verbose = 1
hipace.dt = (Plasma_len)/(clight*maxstep)
diagnostic.output_period = 10
hipace.deposit_rho = 1
hipace.numprocs_x = 1i
hipace.numprocs_y = 1
hipace.do_device_synchronize = 1
amr.max_level = 0
#hipace.comms_buffer_on_gpu=1
#hipace.comms_buffer_max_leading_slices=250
#hipace.comms_buffer_max_trailing_slices=250

geometry.is_periodic = false  false  false  # Is periodic?
geometry.prob_lo     = -0.0001   -10*W0  -0.0001
geometry.prob_hi     =  0.0001   -0.00000    0.0001

lasers.names = laser
lasers.lambda0 = 800e-9
lasers.solver_type = fft
laser.a0 =0.1
laser.position_mean = 0. -2.5*W0 0.
laser.w0 = W0
laser.L0 = 100e-15*clight
lasers.use_phase = 0
laser.init_angle_yz=-0.017
plasmas.names = plasma
plasma.density(x,y,z) = "ne"
plasma.ppc = 1 1
plasma.element = electron

diagnostic.diag_type = yz

And the result is tested by means of python script

N=0
laser_imag1, info_laser_image1 = ts.get_field( iteration=N,  field='laser_imag')
laser_real1, info_laser_real1 = ts.get_field( iteration=N,  field='laser_real')
laser_module1=np.array((laser_real1**2+laser_imag1**2)**0.5)
#laser_module1=laser_module1.T# caculate the modules for N
y_coord1=np.array(info_laser_real1.y)
z_coord1=np.array(info_laser_real1.z)
#cancel the noise in laser_module
laser_module1[laser_module1 < 0.000001] = 0
phi_envelop=np.array(np.arctan2(laser_imag1, laser_real1))
#unwrap phi_envelop
phi_envelop = np.unwrap(phi_envelop, axis=1)
    #filtering"  
window_size = 10
filtered_phi_envelop = np.zeros_like(phi_envelop)
filter_kernel = np.ones(window_size) / window_size
filtered_phi_envelop = np.apply_along_axis(lambda x: np.convolve(x, filter_kernel, mode='same'), axis=1, arr=phi_envelop)
phi_envelop=np.array(filtered_phi_envelop)
#calculate pphi_py
y_diff = np.diff(y_coord1)
pphi_py = (np.diff(phi_envelop, axis=1)) / y_diff
theta1=pphi_py/k0
sigma = np.sum(np.sum(theta1*laser_module1[:,1:len(y_coord1)]))
summ=np.sum(np.sum(laser_module1))
theta_num=(sigma/summ)

The output of theta_num shows that the laser is perfectly initialized with a transverse angle. And the error is small enough to be neglected. And then we let the pulse propagate for 2mm and trace the pulse orbit by the following script:

#plot the position
laser_y=[]
beam_y=[]
z_prop=[]
for N in range(0,210,10):
  laser_imag1, info_laser_image1 = ts.get_field( iteration=N,  field='laser_imag')
  laser_real1, info_laser_real1 = ts.get_field( iteration=N,  field='laser_real')
  laser_module1=np.array((laser_real1**2+laser_imag1**2)**0.5)
  y_coord1=np.array(info_laser_real1.y)
  z_coord1=np.array(info_laser_real1.z)
  ymean=0
  #zmean=0
  sum=0
  for i in range(len(y_coord1)):
    for j in range(len(z_coord1)):
        ymean=ymean+y_coord1[i]*laser_module1[j,i]
        #zmean=zmean+z_coord1[j]*laser_module1[j,i]
        sum=sum+laser_module1[j,i]
  #zmean=zmean/sum
  ymean=ymean/sum
  laser_y.append(ymean)
  z_prop.append(scc.c*N*dt)

Under this resolution, the slope of the orbit is -0.017036.

[MaxThevenet]

Thanks for this PR! See comments below. Could you add some documentation for the user? A NEW entry at the end of this section

hipace/docs/source/run/parameters.rst

Line 758 in c41482d

Laser parameters

would be great.

[MaxThevenet]

The name could be more explicit, and the description is not too accurate. Here is a suggestion. Note that renaming the variable here would require other changes below.

Suggested change

	amrex::Real m_init_angle_yz {0.}; /**< initial angle of laser pulse fron tilt on yoz */
	amrex::Real m_propagation_angle_yz {0.}; /**< Propagation angle of the pulse in the yz plane (0 is the along the z axis) */

[MaxThevenet]

Suggested change

	amrex::Real z = plo[2] + (islice+0.5_rt)*dx_arr[2] - z0;
	amrex::Real x = (i+0.5_rt)*dx_arr[0]+plo[0]-x0;
	amrex::Real y = (j+0.5_rt)*dx_arr[1]+plo[1]-y0;
	const amrex::Real yp=std::cos(init_angle_yz)*y+std::sin(init_angle_yz)*z;
	const amrex::Real zp=-std::sin(init_angle_yz)*y+std::cos(init_angle_yz)*z;
	z=zp;
	y=yp;
	amrex::Real x = (i+0.5_rt)*dx_arr[0]+plo[0]-x0;
	# y and z location of the grid points
	amrex::Real yg = (j+0.5_rt)*dx_arr[1]+plo[1]-y0;
	amrex::Real zg = plo[2] + (islice+0.5_rt)*dx_arr[2] - z0;
	# Rotation in the yz plane to set the laser's propagation direction
	const amrex::Real y=std::cos(init_angle_yz)*yg+std::sin(init_angle_yz)*zg;
	const amrex::Real z=-std::sin(init_angle_yz)*yg+std::cos(init_angle_yz)*zg;

[MaxThevenet]

Could you check if this correction is needed? e.g. by running with zero and non-zero (but small) angle, and checking where the laser is focused?

[AlexanderSinn]

Looks good. Thanks for this PR!

[MaxThevenet]

Thanks for this PR! See inlined comments. Also, could you remove file .DS_Store from the PR?

[MaxThevenet]

Thanks! See minor comments below.