BornAgain ≻ 1.19 ≻ Documentation ≻ Python scripting ≻ Instrument model ≻ Detectors ≻ Adding constant background

Adding constant background

Given a Simulation instance, adding a constant background to it is as easy as:

simulation.setBeamIntensity(1e6)
bg = ba.ConstantBackground(1e3)
simulation.setBackground(bg)

Intensity image

The script below shows how to add a constant background in the context of a GISAXS simulation of an air-substrate bilayer with cylindrical particles embedded.

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#!/usr/bin/env python3
"""
Cylinder form factor in DWBA with constant background
"""
import bornagain as ba
from bornagain import deg, nm


def get_sample():
    """
    Returns a sample with uncorrelated cylinders on a substrate.
    """

    # Define materials
    material_Particle = ba.HomogeneousMaterial("Particle", 0.0006, 2e-08)
    material_Substrate = ba.HomogeneousMaterial("Substrate", 6e-06, 2e-08)
    material_Vacuum = ba.HomogeneousMaterial("Vacuum", 0, 0)

    # Define form factors
    ff = ba.FormFactorCylinder(5*nm, 5*nm)

    # Define particles
    particle = ba.Particle(material_Particle, ff)

    # Define particle layouts
    layout = ba.ParticleLayout()
    layout.addParticle(particle)
    layout.setTotalParticleSurfaceDensity(0.01)

    # Define layers
    layer_1 = ba.Layer(material_Vacuum)
    layer_1.addLayout(layout)
    layer_2 = ba.Layer(material_Substrate)

    # Define sample
    sample = ba.MultiLayer()
    sample.addLayer(layer_1)
    sample.addLayer(layer_2)

    return sample


def get_simulation(sample):
    beam = ba.Beam(1e6, 0.1*nm, ba.Direction(0.2*deg, 0))
    detector = ba.SphericalDetector(100, 2*deg, 1*deg, 1*deg)
    simulation = ba.GISASSimulation(beam, sample, detector)
    background = ba.ConstantBackground(1.0e+03)
    simulation.setBackground(background)
    return simulation


if __name__ == '__main__':
    import ba_plot
    sample = get_sample()
    simulation = get_simulation(sample)
    ba_plot.run_and_plot(simulation)
ConstantBackground.py