Diffractive chain of spheres
05 December, 2023
Source:vignettes/14_diffractive_chain/14_diffractive_chain.Rmd
14_diffractive_chain.RmdObjective
This example considers a chain of 20 Au spheres with relatively large inter-particle separation, commensurate with the wavelength. A strong multiple scattering effect is predicted despite the large distances between scatterers, due to diffractive coupling. The particle-centred scheme (Stout) is required in this calculation, as expanding about a single origin would require prohibitively large multipolar orders for accurate translations (the cluster as a whole has a large size parameter).
This simulation uses the following input file
ModeAndScheme 2 2
MultipoleCutoff 5
MultipoleSelections 1
EE1:1 blocks
OutputFormat HDF5 cross_sections_chain
ScattererCentredCrossSections
Wavelength 300 700 100
Medium 1.7689 # epsilon of water
Incidence 0.0 0.0 0.0
Scatterers 20
Au_S1 -4050 0 0 50
Au_S1 -3600 0 0 50
Au_S1 -3150 0 0 50
Au_S1 -2700 0 0 50
Au_S1 -2250 0 0 50
Au_S1 -1800 0 0 50
Au_S1 -1350 0 0 50
Au_S1 -900 0 0 50
Au_S1 -450 0 0 50
Au_S1 0 0 0 50
Au_S1 450 0 0 50
Au_S1 900 0 0 50
Au_S1 1350 0 0 50
Au_S1 1800 0 0 50
Au_S1 2250 0 0 50
Au_S1 2700 0 0 50
Au_S1 3150 0 0 50
Au_S1 3600 0 0 50
Au_S1 4050 0 0 50
Au_S1 4500 0 0 50 Fixed-orientation results
We compare the fixed-orientation cross-sections to the single-sphere reference (scaled by the particle number),
Rows: 3,636
Columns: 7
$ wavelength <dbl> 300, 300, 300, 300, 300, 300, 300, 300, 300, 300, 300, 300,…
$ crosstype <chr> "Abs", "Abs", "Abs", "Abs", "Abs", "Abs", "Abs", "Abs", "Ab…
$ variable <chr> "total", "total", "I1", "I1", "I2", "I2", "I3", "I3", "I4",…
$ dichroism <dbl> 1.542437e+03, 1.542437e+03, 5.018797e+03, 5.018797e+03, -3.…
$ average <dbl> 1.709526e+05, 1.709526e+05, 1.598596e+05, 1.598596e+05, 1.0…
$ name <chr> "polarisation1", "polarisation2", "polarisation1", "polaris…
$ value <dbl> 1.717238e+05, 1.701814e+05, 1.623690e+05, 1.573502e+05, 8.8…