### Cylinders with size distribution

Scattering from a polydisperse distribution of cylinders in Born Approximation.

• The average radii and heights of the cylinders are equal to $5$ nm.
• The radii of the cylinders vary according to a normal distribution with a standard deviation $\sigma$ equal to $0.2$ times the average radius.
• The wavelength is equal to $1$ $\unicode{x212B}$.
• The incident angles are equal to $\alpha_i = 0.2 ^{\circ}$ and $\varphi_i = 0^{\circ}$.
• There is no substrate (particles embedded in air layer, DWBA boils down to BA).
• No interference effects from inter-particle correlations (dilute-particles approximation).
  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 """ Cylinders with size distribution """ import bornagain as ba from bornagain import deg, nm def get_sample(): """ Return a sample with cylinders on a substrate. The cylinders have a Gaussian size distribution. """ # Define materials material_Particle = ba.HomogeneousMaterial("Particle", 0.0006, 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 particles with parameter following a distribution distr_1 = ba.DistributionGaussian(5*nm, 1*nm) par_distr_1 = ba.ParameterDistribution("/Particle/Cylinder/Radius", distr_1, 100, 2) particle_distrib = ba.ParticleDistribution(particle, par_distr_1) # Define particle layouts layout = ba.ParticleLayout() layout.addParticle(particle_distrib) layout.setTotalParticleSurfaceDensity(0.01) # Define layers layer = ba.Layer(material_Vacuum) layer.addLayout(layout) # Define sample sample = ba.MultiLayer() sample.addLayer(layer) return sample def get_simulation(sample): beam = ba.Beam(1, 0.1*nm, ba.Direction(0.2*deg, 0)) detector = ba.SphericalDetector(200, 2*deg, 1*deg, 1*deg) simulation = ba.GISASSimulation(beam, sample, detector) return simulation if __name__ == '__main__': import ba_plot sample = get_sample() simulation = get_simulation(sample) ba_plot.run_and_plot(simulation) 
CylindersWithSizeDistribution.py