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LHC Optics Web Home

 

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V6.500 -
a version of the LHC optics
Organizational Hierarchy
of the optics
Other Versions of 
the LHC Optics
Help on the data files and formats:    
Structured Spreadsheets Other formats for optics tables MAD output quantities
MAD input examples The Beam Aperture  Interactive 3D viewers
Other links:    
Comparisons between different versions of the LHC Optics MAD input files for past and present versions of the LHC Optics Related links

Access

These LHC Optics Web pages may be accessed via the LHC Project Home (click on the link for "Lattice and Optics") or directly at http://cern.ch/proj-lhc-optics-web/ . 

An easy-to-remember shortcut is:  cern.ch/lhcoptics   You should be able to type this directly into your Web browser's address bar.

Organizational Hierarchy

The data is organized in a hierarchy as follows:

Optics Version
The version of the LHC optics  (e.g., V6.5) corresponding to a defined layout of the machine components.
Configuration
For each Optics Version there are several states of the LHC for which an optics exists (e.g. Injection).  This is defined not only by the power supply settings but also by the nominal parameters of the two beams (energy, emittance, etc.).  From these follow the calculated values of the orbit and optical functions (so-called "Twiss functions").
Selection
Most often, this is a part of the machine (known as a Lattice Module) for which the optical information is presented (e.g., a long straight section like IR2, or a generic ArcCell ).  In such cases values are given at the exits of all the machine elements (dipole magnets, quadrupoles, BPMs, drift spaces, ....).  However, in some cases (e.g., the Interaction Points module) only a selection of elements is used. 
Sequence
This is either "Beam 1" or "Beam 2" (the MAD sequences for the two rings are called LHCB1 and LHCB2), usually presented side-by-side on a Web page. Although one often speaks loosely of Ring 1 or Ring 2, Beam 1 or Beam 2, etc., it should be remembered that both the beam and the hardware are ingredients

Note that the link structure of the Web pages allows this hierarchy to be navigated in different ways, e.g., there are pages corresponding to a Selection which provide links to its appearance in every Configuration.

Each Selection page provide the following sorts of information for both Sequences:

This entire Web site is generated automatically by a Mathematica notebook using the Madtomma packages.

Other formats and information may be added from time to time.

Available Versions of the LHC Optics

The link at the top of this page highlights a single (generally the latest) Optics VersionHowever other versions of the optics, which may be older or newer (possibly not yet officially approved) and additional information are available here. At present, you can find pages giving information about 

The LHC Optics Web does not include older versions than these.  However the MAD input files for all versions remain accessible from

    LHC Optics Source for All Versions = /afs/cern.ch/eng/lhc/optics/

Changes in the data presented are logged here.

Comparisons between different versions of the LHC Optics

It can be important to know exactly what details have changed between one version of the LHC layout and optics and another.  Given the size and complexity of the LHC structure, this is not trivial.  Systematic automated comparisons between some version are available from the Comparisons Between Optics pages.

Related links

MAD home pageMadtomma home page (needs updated)

D. Macina's page on LHC Collision Optics Version V6.5 with links and information geared to experiments.

Optics for other CERN accelerators

Optics files for the CERN PS

SPS to LHC transfer lines TI2TI8.

This Web, the MAD input files and all the data  were created automatically by the Mathematica notebook LHCOpticsWebPages.nb, based on the Madtomma packages.
This page was last modified on Monday, 18 April 2011 11:31:59