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
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
|
#!/usr/bin/env python3
"""
Realistic (imperfect) example for polarized reflectometry.
Sample contains a magnetic layer,
similar to Devishvili et al., Rev. Sci. Instrum. 84, 025112 (2013).
"""
import numpy
import bornagain as ba
from bornagain import nm, ba_plot as bp, deg, R3
from math import sin, cos
def get_sample():
# Materials
Bmag = 1.6e6
Bangle = 0 * deg
B = R3(Bmag*sin(Bangle), Bmag*cos(Bangle), 0)
vacuum = ba.MaterialBySLD("Vacuum", 0, 0)
material_Pd = ba.MaterialBySLD("Pd", 4.0099e-6, 1.3019e-09)
material_Fe = ba.MaterialBySLD("Fe", 8.0241e-06, 6.0448e-10, B)
material_substrate = ba.MaterialBySLD("MgO", 5.9803e-06, 9.3996e-12)
autocorr = ba.SelfAffineFractalModel(2*nm, 0.7, 25*nm)
transient = ba.TanhTransient()
roughness = ba.Roughness(autocorr, transient)
# Layers
layer_vacuum = ba.Layer(vacuum)
layer_Pd = ba.Layer(material_Pd, 12*nm, roughness)
layer_Fe = ba.Layer(material_Fe, 100*nm, roughness)
layer_substrate = ba.Layer(material_substrate, roughness)
# Multilayer
sample = ba.Sample()
sample.addLayer(layer_vacuum)
sample.addLayer(layer_Pd)
sample.addLayer(layer_Fe)
sample.addLayer(layer_substrate)
return sample
def simulate(p_dir, a_dir, p_eff, a_eff, title):
sample = get_sample()
qzs = numpy.linspace(0.1, 1.5, 1500)
distr = ba.DistributionGaussian(0., 1., 25, 4.)
scan = ba.QzScan(qzs)
scan.setAbsoluteQResolution(distr, 0.008)
scan.setPolarization(p_dir*p_eff)
scan.setAnalyzer(a_dir*a_eff)
simulation = ba.SpecularSimulation(scan, sample)
simulation.setBackground(ba.ConstantBackground(1e-7))
result = simulation.simulate()
result.setTitle(title)
return result
if __name__ == '__main__':
# polarizer and analyzer efficiencies
p_eff = 0.986
a_eff = 0.970
results_pp = simulate(R3(0, +1, 0), R3(0, +1, 0), p_eff, a_eff, "$++$")
results_pm = simulate(R3(0, +1, 0), R3(0, -1, 0), p_eff, a_eff, "$+-$")
results_mp = simulate(R3(0, -1, 0), R3(0, +1, 0), p_eff, a_eff, "$-+$")
results_mm = simulate(R3(0, -1, 0), R3(0, -1, 0), p_eff, a_eff, "$--$")
results = [results_pp, results_pm, results_mp, results_mm]
from bornagain import ba_check
ba_check.persistence_test(results)
|
