Collimations
H-K-L-ω
Energy
Mosaic
Lattice
Orientation
Overview
Orientation 1
Orientation 2
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.
a b c
Å (e.g.,
6.28
or
3 4 5
)
α β γ
degrees (e.g.,
90
or
90 90 120
)
Monochromator mosaic
min
τ
pg(002)
pg(004)
ge(111)
ge(220)
ge(311)
be(002)
pg(110)
Analyzer mosaic
min
τ
pg(002)
pg(004)
ge(111)
ge(220)
ge(311)
be(002)
pg(110)
2axis
Sample horz mosaic
min
Sample vert mosaic
min
Fixed energy
Ei
Ef
meV
Horizontal collimator
min (e.g.,
40
or
40 47 40 200
)
Vertical collimator
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)
Graph
Table