Time-of-flight reflectometry

This example shows how to set up a $q_z$ scan using a NumPy array. This can be used to simulate a time-of-flight (TOF) reflectometry experiment.

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#!/usr/bin/env python3
"""
An example of defining reflectometry instrument
for time of flight experiment. In this example
we will use purely qz-defined beam,
without explicitly specifying
incident angle or a wavelength.
Note that these approaches work with SLD-based
materials only.
"""
import numpy as np
import bornagain as ba
from bornagain import ba_plot as bp, nm


def get_sample():
    """
    Twenty alternating Ti and Ni layers on a silicon substrate.
    """
    ambient_mat = ba.Vacuum()
    ti_mat = ba.SLDMaterial("Ti", (0.05, 0.62, 0.55), -1.9493e-6, 0)
    ni_mat = ba.SLDMaterial("Ni", (0.93, 0.48, 0.14), 9.4245e-6, 0)
    substrate_mat = ba.SLDMaterial(
        "SiSubstrate", (0.28, 0.57, 0.82), 2.0704e-6, 0)

    stack = ba.LayerStack(10)
    stack.addLayer(ba.Layer(ti_mat, 3*nm))
    stack.addLayer(ba.Layer(ni_mat, 7*nm))

    sample = ba.Sample()
    sample.addLayer(ba.Layer(ambient_mat))
    sample.addStack(stack)
    sample.addLayer(ba.Layer(substrate_mat))
    return sample


def get_simulation(sample):
    "Specular simulation with a qz-defined beam"
    n = 500
    qzs = np.linspace(0.01, 1, n)  # qz-values
    scan = ba.QzScan(qzs)
    return ba.SpecularSimulation(scan, sample)


if __name__ == '__main__':
    sample = get_sample()
    ba.showSample3D(sample, sample_size=120*nm, seed=0)
    simulation = get_simulation(sample)
    result = simulation.simulate()
    bp.plot_datafield(result)
    bp.plt.show()
auto/Examples/specular/TimeOfFlightReflectometry.py