A sample for phonon scattering
based on cross section expressions from Squires, Ch.3.
Author: Kim Lefmann
No multiple scattering.
No incoherent scattering emitted.
No attenuation from coherent scattering. No Bragg scattering.
fcc crystal n.n. interactions only
One phonon branch only -> phonon polarization not accounted for.
Bravais lattice only. (i.e. just one atom per unit cell)
0. Always perform the scattering if possible (otherwise ABSORB)
1. Choose direction within a focusing solid angle
2. Calculate the zeros of (E_i-E_f-hbar omega(kappa)) as a function of k_f
3. Choose one value of k_f (always at least one is possible!)
4. Perform the correct weight transformation
Parameters in boldface are required;
the others are optional.
Outer radius of sample in (x,z) plane
Height of sample in y direction
Absorption cross section at 2200 m/s per atom
Incoherent scattering cross section per atom
fcc Lattice constant
Velocity of sound
position of target to focus at . Transverse coordinate
position of target to focus at. Vertical coordinate
position of target to focus at. Straight ahead.
relative index of component to focus at, e.g. next is +1