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
|
#!/usr/bin/env python3
"""
Introductory example for polarized neutron reflectivity.
Sample is a magnetic layer.
"""
import bornagain as ba
from bornagain import angstrom, ba_plot as bp, deg, nm, R3
from math import sin, cos
def get_sample():
# Magnetic field
Bmag = 1e8
Bangle = 60*deg
B = R3(Bmag*cos(Bangle), Bmag*sin(Bangle), 0)
# Materials
vacuum = ba.MaterialBySLD("Vacuum", 0, 0)
material_layer = ba.MaterialBySLD("Layer", 0.0001, 1e-08, B)
material_substrate = ba.MaterialBySLD("Substrate", 7e-05, 2e-06)
# Layers
layer_1 = ba.Layer(vacuum)
layer_2 = ba.Layer(material_layer, 10*nm)
layer_3 = ba.Layer(material_substrate)
# Sample
sample = ba.Sample()
sample.addLayer(layer_1)
sample.addLayer(layer_2)
sample.addLayer(layer_3)
return sample
def simulate(sample, polarizer_vec, analyzer_vec, title):
n = 50
scan = ba.AlphaScan(n, 5*deg/n, 5*deg)
scan.setWavelength(1.54*angstrom)
scan.setPolarization(polarizer_vec)
scan.setAnalyzer(analyzer_vec)
simulation = ba.SpecularSimulation(scan, sample)
result = simulation.simulate()
result.setTitle(title)
return result
if __name__ == '__main__':
sample = get_sample()
results = [
simulate(sample, R3(0, +1, 0), R3(0, +1, 0), "$++$"),
simulate(sample, R3(0, +1, 0), R3(0, -1, 0), "$+-$"),
simulate(sample, R3(0, -1, 0), R3(0, -1, 0), "$--$"),
]
from bornagain import ba_check
ba_check.persistence_test(results)
|
