About
This calculator uses the Gaussian approximation for collimator transmission functions and mosaic distributions of the monochromator and analyzer crystals, following the treatment by Cooper and Nathans.
Developed by: William Ratcliff at the NIST Center for Neutron Research.
Collimations
The four collimations are post-neutron-source, post-monochromator, post-sample, and post-analyzer.
H-K-L-w
A series of reciprocal lattice vectors (h, k, l) and energy transfer (w) may be entered.
Energy
Define either fixed final (Ef) or incident (Ei) energy, where the wavelength is 9.045/sqrt(E).
Mosaic

Lattice
The lattice parameters (a, b, c) and angles ($\alpha$, $\beta$, $\gamma$).
Orientation
Define the scattering plane.
Table
h:user defined
k:user defined
l:user defined
$\omega$:user defined
$\theta$ correction: multiplicative factor for intensity from structure factor squared for a $\theta$ scan, such that I ~ "$\theta$ correction" x $|F_N|^2$
$\theta$ correction: multiplicative factor for intensity from structure factor squared for a 2$\theta$ scan, such that I ~ "$2\theta$ correction" x $|F_N|^2$
$\theta$ width cross-section (degrees)
$\theta$ width projection (degrees)
$2\theta$ width cross-section (degrees)
$2\theta$ width projection (degrees)
$\omega$ width cross-section (meV)
QX Lab width cross-section (Å)
QY Lab width cross-section (Å)
$\omega$ width projection (meV)
QX Lab width projection (Å)
QY Lab width projection (Å)
QZ width projection (Å)
R$_0$ : scalar resolution prefactor
R$_{CN}$ : resolution 4-vector, which is a function of $\frac{m_n w}{\hbar Q}$, $Q_\parallel$, $Q_\perp$, and $Q_z$
Graph
The purple ellipses represent the cross section of the ellipsoid with a given plane, while peach ellipses show the projection onto the plane.
Å (e.g., 6.28 or 3 4 5)
degrees (e.g., 90 or 90 90 120)
min
min
min
min
meV
min (e.g., 40 or 40 47 40 200)
min (e.g., 120 or 120 120 120 120)
Enter one value of h, k, l, ω for each point:
h (e.g., 1 or 1 2 3 4 …)
k
l
ω meV(energy transfer)