1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
|
<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE html
PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US" xml:lang="en-US">
<head>
<title>(IUCr) CIF Definition save__diffrn_radiation.polarizn_source_ratio</title>
<link rel="stylesheet" type="text/css" href="../../itg.css" />
</head>
<body>
<!-- begin masthead -->
<div class="masthead">
<table class="masthead">
<tr>
<td class="masthead" width="30%">
<p class="title">DRAFT DICTIONARY</p>
<p class="title"><font class="smalltitle"></font>CBF/imgCIF Extensions Dictionary</p>
</td>
<td class="masthead">
<p class="title">Draft version 1.5 for comment</p>
</td>
</tr>
</table>
</div>
<!-- end masthead -->
<hr>
<H1>
<a href="http://www.iucr.org/iucr-top/welcome.html">
<img alt="[IUCr Home Page]" src="../html_graphics/iucrhome.jpg" ALIGN=MIDDLE></a>
<a href="http://www.iucr.org/iucr-top/cif/home.html">
<img alt="[CIF Home Page]" src="../html_graphics/cifhome.jpg" ALIGN=MIDDLE></a>
<a href="cbf_definition_rev.html"><IMG SRC="../html_graphics/CBFbutton.jpg"
ALT="[CBF/imgCIF]" ALIGN=MIDDLE></a>
<a href="CBFlib.html"><IMG SRC="../html_graphics/cbflibbutton.jpg"
ALT="[CBFlib]" ALIGN=MIDDLE></a>
</H1>
<hr>
<!-- begin navbar -->
<div class="navbar">
<table class="navbar">
<tr>
<td><a class="navbar" href="index.html">Contents</a></td>
</tr>
</table>
</div>
<!-- end navbar -->
<p class="index"><a class="index" href="index.html">Index</a></p>
<h5>Image dictionary (imgCIF) version 1.5.4</h5>
<h1>_diffrn_radiation.polarizn_source_ratio</h1><b>Name:</b><br /><tt class="cifdefinition">'_diffrn_radiation.polarizn_source_ratio'</tt>
<p><b>Definition:</b></p><pre class="cifdefinition">
(Ip-In)/(Ip+In), where Ip is the intensity
(amplitude squared) of the electric vector in the plane of
polarization and In is the intensity (amplitude squared)
of the electric vector in the plane of the normal to the
plane of polarization.
In the case of an unpolarized beam, or a beam with true
circular polarization, in which no single plane of
polarization can be determined, the plane is to be taken
as the XZ plane and the normal is parallel to the Y axis.
Thus, if there was complete polarization in the plane of
polarization, the value of
<a href="Idiffrn_radiation.polarizn_source_ratio.html" class="itemlink">_diffrn_radiation.polarizn_source_ratio</a> would be 1, and
for an unpolarized beam
<a href="Idiffrn_radiation.polarizn_source_ratio.html" class="itemlink">_diffrn_radiation.polarizn_source_ratio</a> would have a
value of 0.
If the X axis has been chosen to lie in the plane of
polarization, this definition will agree with the definition
of 'MONOCHROMATOR' in the Denzo glossary, and values of near
1 should be expected for a bending-magnet source. However,
if the X axis were perpendicular to the polarization plane
(not a common choice), then the Denzo value would be the
negative of <a href="Idiffrn_radiation.polarizn_source_ratio.html" class="itemlink">_diffrn_radiation.polarizn_source_ratio</a>.
See http://www.hkl-xray.com for information on Denzo and
Otwinowski & Minor (1997).
This differs both in the choice of ratio and choice of
orientation from <a href="Idiffrn_radiation.polarisn_ratio.html" class="itemlink">_diffrn_radiation.polarisn_ratio</a>, which,
unlike <a href="Idiffrn_radiation.polarizn_source_ratio.html" class="itemlink">_diffrn_radiation.polarizn_source_ratio</a>, is
unbounded.
Reference: Otwinowski, Z. & Minor, W. (1997). 'Processing of
X-ray diffraction data collected in oscillation mode.' Methods
Enzymol. 276, 307-326.
</pre>
<p><b>Type:</b> float</p>
<p class="pack"><b>Mandatory item:</b> no</p>
<br />The permitted range is [-1.0, 1.0]<br />
<p class="pack"><b>Category:</b> <a href="Cdiffrn_radiation.html" class="catlink">diffrn_radiation</a></p>
<h4 align=left>
HTML version of draft dictionary created by modified version of makedicthtml by B. McMahon
from modified version of imgCIF dcitionary 1.3.2 which is subject to the following copyright:
</h4>
<!-- begin copyright -->
<div class="copyright">
<p class="copyright">Copyright © 2005 International Union of Crystallography</p>
</div>
<!-- end copyright -->
</body>
</html>
|
