source: PSPA/madxPSPA/doc/usrguide/survey/survey.html @ 430

Last change on this file since 430 was 430, checked in by touze, 11 years ago

import madx-5.01.00
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1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
2<html>
3<head>
4  <title>Geometric Layout</title>
5<!-- Created by: Andre VERDIER, 21-Jun-2002 --><!-- Changed by: Andre Verdier, 25-Jun-2002 --><!-- Changed by: Hans Grote, 30-Sep-2002 --><!-- Changed by: Andre Verdier, 14-Jan-2003 --><!-- Directory :  /afs/cern.ch/eng/sl/MAD-X/pro/docu/survey/ -->
6</head>
7<body bgcolor="#ffffff">
8<center>
9EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH
10<img SRC="http://cern.ch/madx/icons/mx7_25.gif" align="right">
11<h1>GEOMETRIC LAYOUT</h1>
12</center>
13<br>
14<p>
15The SURVEY command computes the coordinates of all machine elements in
16a
17<a href="../Introduction/conventions.html">global reference system</a>.
18These coordinates can be used for installation. In order to produce
19coordinates in a particular system, the initial coordinates and angles
20can be specified. The computation results are written on an
21internal table (survey)&nbsp; and can be written on
22an external file. Each line contains the coordinates at the end of the
23element.<br>
24The last "USEd" sequence is used
25except if another one is specified.<br>
26</p>
27<center>-----------------------------------------------------------------------------------------</center>
28<br>
29WARNING : in the case a machine geometry is constructed with thick
30lenses,
31the circumference will change if the structure is converted into thin
32lenses (via the <a href="../makethin/makethin.html">makethin</a>
33command).
34This is an unavoidable feature. ONLY the structure with thick lenses
35must be used
36for practical purposes.<br>
37INFORMATION : The skew dipole component of a MULTIPOLE element
38(MULTIPOLE, KSL={FLOAT}) is NOT taken into account in the survey
39calculation. You should use a tilted normal MULTIPOLE or BEND instead.<br>
40<br>
41<center>-----------------------------------------------------------------------------------------</center>
42<br>
43The survey calculation is launched by a single command line with the
44following syntax :
45<br>
46<br>
47<pre>
48SURVEY, x0=double, y0=double, z0=double,
49        theta0=double, phi0=double, psi0=double,
50        file=string, table=string, sequence=string;
51
52parameter   meaning                                     default value
53x0          initial horizontal transverse coordinate    0.0
54y0          initial vertical   transverse coordinate    0.0
55z0          initial longitudinal coordinate             0.0
56theta0      initial horizontal angle                    0.0
57phi0        initial vertical angle                      0.0
58psi0        initial transverse tilt                     0.0
59file        name of external file                       null (default name survey)
60table       name of internal table                      null (ignored, always table='survey')
61sequence    name of sequence to be surveyed             last used sequence
62</pre>
63
64<h2> Example : average LHC ring with CERN coordinates.</h2>
65
66<pre>
67real const R0 = 1.0;          ! to obtain the average ring
68OPTION, -echo, -info;
69CALL, file="V6.4.seq.070602"; ! follow this <a href="V6.4.seq.070602">link</a> for the file
70OPTION, echo;
71BEAM, particle=proton, energy=450, sequence=lhcb1;
72USE, period=lhcb1;
73! SELECT, flag=survey,clear;  ! uncomment if the optional select below is used
74! optional SELECT to specify a class and the output columns
75! SELECT, flag=survey, class=marker, column=name,s,psi;
76SURVEY, x0=-2202.21027, z0=2710.63882, y0=2359.00656,
77        theta0=-4.315508007, phi0=0.0124279564, psi0=-0.0065309236,
78        file=survey.lhcb1;
79<a href="../control/general.html#write">WRITE</a>, table=survey; ! to display the results immediately
80STOP;
81!*********** The external file "survey.lhcb1" can now be read **************
82</pre>
83<i>F.Tecker, March 2006</i>
84</body>
85</html>
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