calculates neutron scattering intensity for spin wave spectrum
spectra = SW_NEUTRON(spectra, 'Option1', Value1' ...)
It calculates neutron scattering intensity for polarised and unpolarised
neutron scattering on spin waves.
Input:
spectra Input structure that contains the spin-spin correlation
function.
Options:
uv Cell, that contains two vectors, that define the scattering
plane in r.l.u. For example: {[1 0 0] [0 1 0]} for the hk
plane.
n Normal vector to the scattering plane, in real space (xyz
coordinate system), dimensions are [1 3]. Default is [0 0 1].
pol Whether to calculate cross sections in the Blume-Maleev
coordinate system (inP, Pab and Mab fields of spectra). Default
is false.
Output:
the spectra output has the following additional fields:
param Input parameters.
Sperp Sperp(mode,Q) unpolarised neutron scattering cross section,
dimensions are [nMode nHkl].
intP intP(Pi,mode,Q) polarised scattering cross section, dimensions
are [3 nMode nHkl].
Pab Pab(Pf,Pi,mode,Q) complete polarised scattering cross section,
dimensions are [3 3 nMode nHkl].
Mab Mab(Pf,Pi,mode,Q) components of the correlation function,
dimensions are [3 3 nMode nHkl].
If several domains exist in the sample, Sperp, intP, Pab and Mab are
packaged into a cell, that contains nTwin number of matrices.
The meaning of the indices:
Pi index of incident polarisation (1=xBM, 2=yBM or 3=zBM),
Pf index of final polarisation (1=xBM, 2=yBM or 3=zBM),
mode index of spin wave mode,
Q index of momentum transfer.
The polarisation components Pi and Pf defines the Blume-Maleev coordinate
system with (xBM, yBM and zBM) basis vectors as follows:
xBM parallel to the momentum transfer Q,
yBM perpendicular to Px in the scattering plane,
zBM perpendicular to the scattering plane.
See also SW, SW.SPINWAVE.