includes instrumental factors into the calculated spectrum
spectra = SW_INSTRUMENT(spectra, 'option1','value1',...)
It includes instrumental factors (resolution, energy transfer range,
etc.) to the convoluted spectrum.
Options:
dE Defines the energy resolution of the instrument. It can be
a string, single number, vector of function hangle:
String File name, that contains the FWHM energy
resolution values as a function of energy
transfer. The file has to contain two columns,
first is the energy values, the second is the
FWHM resolution at the given energy transfer
value, see sw_res() function for details.
Number Constant FWHM energy resolution as a function
of energy transfer.
Matrix Dimensions of Nx2, first column contains the
energy transfer values, second column contains
the FWHM resolution values. These values will
be fitted using a polynomial with a fixed
degree, see sw_res() function for details.
Function Function handle of a resolution function
with the following header:
E_FWHM = res_fun(E)
where E_FWHM is the FWHM energy resolution and
E is the energy transfer value.
polDeg Degree of the fitted polynomial to the instrumental
resolution data. Default is 5.
dQ Momentum transfer resolution of the instrument, FWHM is
given in A-1 units, default is 0.
ThetaMin Minimum scattering angle in degree, default is 0.
plot If the resolution is read from file and plot option is
true, tre resolution will be plotted, default is true.
Fixed incident neutron energy:
ki Momentum of the incident neutrons in A^-1 units.
Ei Energy of the incident neutrons in meV.
Fixed final neutron energy:
kf Final momentum of the neutrons in A^-1 units.
Ef Final neutron energy in meV.
norm If true, the data is normalized to mbarn units. Default is
true. If no g-tensor is included in the spin wave
calculation, g-tensor = 2 is assumed here.
useRaw If false, the already modified spectra.swConv field is
modified further instead of the original powder spectrum
stored in spectra.swRaw. Default is true.
Output:
spectra Struct variable, same as input with following additional
fields:
norm True, if the spectrum is normalised to mbarn units.
ki Incident neutron wave vector as given in the input.
dE Energy resolution polynomial as given in the input.
dQ FWHM of the momentum resolution.
swRaw Original simulated data, withouth the application of the
instrumental factors.
See also POLYFIT, POLYVAL, SW_RES.