Time-of-flight reflectometry

This short tutorial quickly illustrates the setup of a time-of-flight (TOF) reflectometry simulated experiment.

Setting up a TOF simulation boils down to specifying the range of values spanned by the $q_z$ vector, rather than the range spanned by the angle $\theta$ of the beam:

    qzs = np.linspace(0.01, 1.0, scan_size)  # qz-values
    scan = ba.QSpecScan(qzs)
    simulation = ba.SpecularSimulation()
    simulation.setScan(scan)

This figure shows the reflectometry signal obtained after running the TOF simulation of the script below.

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
#!/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, std_samples


def get_sample():
    return std_samples.alternating_layers()


def get_simulation(sample):
    """
    Defines and returns specular simulation
    with a qz-defined beam
    """
    n = bp.simargs['n']
    qzs = np.linspace(0.01, 1, n)  # qz-values
    scan = ba.QzScan(qzs)
    return ba.SpecularSimulation(scan, sample)


if __name__ == '__main__':
    bp.parse_args(sim_n=500)
    sample = get_sample()
    simulation = get_simulation(sample)
    result = simulation.simulate()
    bp.plot_simulation_result(result)
Examples/specular/TimeOfFlightReflectometry.py