Chemistry Reference
In-Depth Information
q The modulus of the scattering vector, most frequently used in the small angle
scattering.
r The distance between a pixel on an area detector and the sample.
r
f
Radius of the focusing circle in Bragg-Brentano geometry.
r
ij
Ratio of the contributing area to the whole pixel area used for spatial correction.
Residuals for detector calibration by the least square fitting.
R The resolution of a SAXS system defined as the theoretically largest resolvable
Bragg spacing.
Radius of goniometer circle in Bragg-Brentano geometry.
Count rate of a detector.
R
B
The noise rate of a photon counting detector.
R
DL
The count rate at detection limit.
R
i
Reflection factor used for retained austenite measurement (i stands for different
phases).
R
global
The global count rate of an area detector (in cps).
R
local
The local count rate of an area detector (in cps/mm
2
).
R
pixel
The pixel count rate of an area detector (in cps/pixel).
R
m
The measured count rate with counting loss DR.
R
BS
The resolution of limit of the beam stop of a SAXS system.
R
x
, R
y
, R
z
The detector rotations about three axes, also referred to as roll, pitch, and yaw.
s
0
The unit vector of the incident beam.
s
The unit vector of the diffracted beam.
S
The spot size of an X-ray beam on the sample.
S
1
One of the two macroscopic elastic constants used for stress measurement, also
expressed as S
1
(hkl) if the anisotropic correction for a specific crystalline
plane is considered.
The size of an X-ray source.
S
fhklg
1
One of the two X-ray elastic constants (XECs) for crystal planes {hkl}.
2
S
2
One of the two macroscopic elastic constants.
2
S
fhklg
One of the two X-ray elastic constants for crystal planes {hkl}.
2
S
x, y
Sensitivity normalization factor for the pixel Pðx
;
yÞ.
S
ijkl
Elastic compliances.
S
1
One of the sample coordinates. It is in the same direction as the sample
translation axis X except the origin is fixed on sample.
S
2
The size of an X-ray image after X-ray optic device.
S
2
One of the sample coordinates. It is in the same direction as the sample
translation axis Y except the origin is fixed on sample.
S
3
One of the sample coordinates. It is in the same direction as the sample
translation axis Z except the origin is fixed on sample.
T
Transmission coefficient.
The sample transmission coefficient normalized by A
BB
. T¼A/A
BB
.
T
mn
l
ðgÞ
Generalized spherical harmonic functions, l is the order of the series, andmand n
denote finite numbers of independent C-coefficient at each order.
v
Volume of unit cell.
v
i
Volume of individual crystallites of the ith phase.
V
The volume of the crystal unit cell.
Effective sampling volume in diffraction.
Voltage applied to the X-ray generator.
