#
#
# This example shows the diffraction by a Si 111 crystal calculated in its simplest implementation:
#
#
# - calculate_simple_diffraction()
# Uses a crystal setup and calculates the complex transmitivity and reflectivity
#
#
import numpy
from crystalpy.diffraction.GeometryType import BraggDiffraction
from crystalpy.diffraction.DiffractionSetupXraylib import DiffractionSetupXraylib
from crystalpy.diffraction.Diffraction import Diffraction
from crystalpy.util.Vector import Vector
from crystalpy.util.Photon import Photon
#
def calculate_simple_diffraction(calculation_method=0, calculation_strategy_flag=0):
# Create a diffraction setup.
print("\nCreating a diffraction setup...")
diffraction_setup = DiffractionSetupXraylib(geometry_type = BraggDiffraction(), # GeometryType object
crystal_name = "Si", # string
thickness = 1e-2, # meters
miller_h = 1, # int
miller_k = 1, # int
miller_l = 1, # int
asymmetry_angle = 0,#10.0*numpy.pi/180., # radians
azimuthal_angle = 0.0) # radians # int
energy = 8000.0 # eV
angle_deviation_min = -100e-6 # radians
angle_deviation_max = 100e-6 # radians
angle_deviation_points = 500
angle_step = (angle_deviation_max-angle_deviation_min)/angle_deviation_points
#
# gets Bragg angle needed to create deviation's scan
#
bragg_angle = diffraction_setup.angleBragg(energy)
print("Bragg angle for E=%f eV is %f deg"%(energy,bragg_angle*180.0/numpy.pi))
# initialize arrays for storing outputs
deviations = numpy.zeros(angle_deviation_points)
intensityS = numpy.zeros(angle_deviation_points)
intensityP = numpy.zeros(angle_deviation_points)
for ia in range(angle_deviation_points):
deviation = angle_deviation_min + ia * angle_step
angle = deviation + bragg_angle
# calculate the components of the unitary vector of the incident photon scan
# Note that diffraction plane is YZ
yy = numpy.cos(angle)
zz = - numpy.abs(numpy.sin(angle))
photon = Photon(energy_in_ev=energy,direction_vector=Vector(0.0,yy,zz))
# perform the calculation
coeffs = Diffraction.calculateDiffractedComplexAmplitudes(diffraction_setup, photon,
calculation_method=calculation_method,
calculation_strategy_flag=calculation_strategy_flag)
# store results
deviations[ia] = deviation
intensityS[ia] = numpy.abs(coeffs['S']) ** 2
intensityP[ia] = numpy.abs(coeffs['P']) ** 2
# plot results
import matplotlib.pylab as plt
plt.plot(1e6*deviations,intensityS)
plt.plot(1e6*deviations,intensityP)
plt.xlabel("deviation angle [urad]")
plt.ylabel("Reflectivity")
plt.legend(["Sigma-polarization","Pi-polarization"])
plt.show()
#
# main
#
if __name__ == "__main__":
calculation_method = 1 # 0=Zachariasen, 1=Guigay
calculation_strategy_flag = 2 # 0=mpmath 1=numpy 2=numpy-truncated
# calculate_simple_diffraction(calculation_method=calculation_method, calculation_strategy_flag=calculation_strategy_flag)
import numpy
from crystalpy.util.calc_xcrystal import calc_xcrystal_angular_scan, calc_xcrystal_energy_scan, calc_xcrystal_alphazachariasen_scan
bunch_out_dict, diffraction_setup, deviations = calc_xcrystal_angular_scan(
# material_constants_library_flag=self.material_constants_library_flag,
crystal_name = 'Si',
thickness = 0.008, #1e-2, #0.007,
miller_h = 1,
miller_k = 1,
miller_l = 1,
asymmetry_angle = 0.0,
energy = 8000.0,
angle_deviation_min = -0.0001,
angle_deviation_max = 0.0001,
angle_deviation_points = 200,
angle_center_flag = 2,
calculation_method = 1, # 0=Zachariasen, 1=Guigay
is_thick = 0,
use_transfer_matrix = 0,
geometry_type_index = 0,
calculation_strategy_flag = 2, # 0=mpmath 1=numpy 2=numpy-truncated
)
tmp = numpy.zeros((bunch_out_dict["energies"].size,7))
tmp[:, 0] = deviations / 1e-06
tmp[:, 1] = 8000.0
tmp[:, 2] = bunch_out_dict["phaseP"]
tmp[:, 3] = bunch_out_dict["phaseS"]
# tmp[:, 4] = circular polarization
tmp[:, 5] = bunch_out_dict["intensityP"]
tmp[:, 6] = bunch_out_dict["intensityS"]
from srxraylib.plot.gol import plot
plot(tmp[:,0], tmp[:,6], tmp[:,0], tmp[:,5], xtitle="angle", legend=["S-pol","P-pol"])
