### Interference - Superposition of Square Lattices

This example demonstrates how to perform a simulation of scattering from cylinders distributed in a square lattice fashion. The resultant 2D lattice is a sum of rotated lattices with different disorder.

This example is similar to Interference of a rotated square lattice.

  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  import bornagain as ba from bornagain import deg, nm def get_sample(): """ Returns a sample with cylinders on a substrate, forming a 2D lattice with different disorder rotated lattice """ m_vacuum = ba.HomogeneousMaterial("Vacuum", 0.0, 0.0) m_substrate = ba.HomogeneousMaterial("Substrate", 6e-6, 2e-8) m_particle = ba.HomogeneousMaterial("Particle", 6e-4, 2e-8) vacuum_layer = ba.Layer(m_vacuum) substrate_layer = ba.Layer(m_substrate) p_interference_function = \ ba.InterferenceFunction2DLattice(ba.SquareLattice2D(25.0*nm, 0)) pdf = ba.FTDecayFunction2DCauchy(48*nm, 16*nm, 0) p_interference_function.setDecayFunction(pdf) particle_layout = ba.ParticleLayout() ff = ba.FormFactorCylinder(3.0*nm, 3.0*nm) position = ba.kvector_t(0.0, 0.0, 0.0) cylinder = ba.Particle(m_particle, ff.clone()) cylinder.setPosition(position) particle_layout.addParticle(cylinder, 1.0) particle_layout.setInterferenceFunction(p_interference_function) vacuum_layer.addLayout(particle_layout) multi_layer = ba.MultiLayer() multi_layer.addLayer(vacuum_layer) multi_layer.addLayer(substrate_layer) return multi_layer def get_simulation(sample): beam = ba.Beam(1.0, 0.1*nm, ba.Direction(0.2*deg, 0*deg)) detector = ba.SphericalDetector(100, 2*deg, 1*deg, 1*deg) simulation = ba.GISASSimulation(beam, sample, detector) distr_1 = ba.DistributionGate(0*deg, 240*deg) simulation.addParameterDistribution("*/SquareLattice2D/Xi", distr_1, 3, 0.0) return simulation if __name__ == '__main__': import ba_plot sample = get_sample() simulation = get_simulation(sample) ba_plot.run_and_plot(simulation) 
Interference2DLatticeSumOfRotated.py