Groups
Div. officers & representatives
Committees, meetings, conferences
Geometry description with SIMPLEGEO
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Geometry layout
IR1
| Dates | Meetings and discussions |
| 19th January, 2007 |
The layout data have been collecting in
2006 with the vacuum group ( contacts: Raymond Veness, Herve
Prin, Willie Cameron).
David Widegren shows us a LHC layout data tool, for double checking our data (functionnal position layout). They are designed values for LHC v6.5.1. A first meeting was held to explain our needs and to see how we could access a more convenient and systematic way the IR5 layout. http://layout.web.cern.ch/layout/ The layout data has been summarized in the following excel file: geometry-description-excel file
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| 5th February, 2007 | The building geometry and the methodology in Geometry building is described in details with the different steps. |
IR5
| Dates | Meetings and discussions |
| contact: Patrick Lepeule | |
| June 2007 | contact: Markus
Brugger A input file cms_new_full_v3.new.inp have been recuperated from CMS (Mika Huhtinen): this input file includes the all geometry of the CMS detector with a cylindrical description. It also includes the beam pipes description from the IP5 to the TAS. the latter elements have been identified and compared to drawings to build the beam pipe layout of IR5 before the TAS. To build the IR5 detailed geometry, the IR1 model have been used, replacing the beam pipe layout before the TAS, by the one for IR5. The beam screens have a different configuration. they are vertical ( horizontal crossing angle). The other parts are identical for both IR1 and IR5 |
| July 2007 | A IR5 toy
model have been built with both FLUKA and MARS
IR5_toy.inp (FLUKA) IR5_toy.inp (MARS)
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SIMPLEGEO implementation
Precision of the layout
The insertion region consist mostly of vacuum chambers, and insertion elements: superconducting magnets, TAS, BPM, transition valves...
The variations of the inner diameter of the tubes have to be taken into account. It has been decided not to simplify any change of diameter, or thickness of the tubes.
Body elements for vacuum chambers
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finite cylinders and truncated cones:
There can be disadvantages to use these finite volumes for computation time and precision issues with FLUKA.
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infinite cylinder with cutting planes.
Methodology
19/01/07 meeting with Eduard Feldbaumer
For building complex geometry with SIMPLEGEO, we would like to adopt a systematic method with sub group descriptions, in order to divide the geometry in different parts that could be handled separately. A simple merging of the different groups at the very last step would allow to have the complete geometry.
Recommendations:
- use one absolute coordinate system and all the groups are defined in this same system. Any translation or rotation operations should be avoided after the groups are merged.
- well identify the separate groups: the best is to have groups physically separated by air. The group is surrounded by a simple test volume (ex: box) and the merging would be performed with this simple test volume (subtraction operation)
- In case of continuous geometry (sequences of longitudinal tubes), the idea is to enlarge the the border elements in order to make a proper merge operation
- when merging the groups, use the 'skin volume' to perform the subtraction operation. There should be no brackets for region definitions.
PEOPLE TO CONTACT
CERN
Christine Hoa: christine.hoa@cern.ch
INFN
| Updated 2007-5-2 by C.HOA | Author: C.HOA |