SCT Geometry Status: December 2000

SCT Geometry Status DISCLAIMER:DISCLAIMER: –These slides are only going to deal with AGDD/XML related geometry issues. This talk is only meant to describe the work I have been closely involved in. Where are we now?Where are we now? Where are we going?Where are we going? Related work.Related work.

Q: On the full SCT geometry, where are we now? A: Largely where we were in August!A: Largely where we were in August! The present AGDD representation of the full SCT geometry in Geant4 is still the transcription from DICE/AGE of the geometry used for the Inner Detector TDR.The present AGDD representation of the full SCT geometry in Geant4 is still the transcription from DICE/AGE of the geometry used for the Inner Detector TDR.

Barrel SCT Geometry

Forward SCT Geometry

How is our geometry produced? We have a basic set of numbers which parametrise the detector. These happen to be stored in an XML file called a “preXml file”.We have a basic set of numbers which parametrise the detector. These happen to be stored in an XML file called a “preXml file”. We have geometrical knowledge hard coded into a C++ program. This “Geometry code” can read the preXml file and generate an AGDD/XML file.We have geometrical knowledge hard coded into a C++ program. This “Geometry code” can read the preXml file and generate an AGDD/XML file. The production of a well formed AGDD/XML file is made easier by using a set of generic tools provided by “AGDD_XmlFileBuilder”.The production of a well formed AGDD/XML file is made easier by using a set of generic tools provided by “AGDD_XmlFileBuilder”. AGDD_XmlFileBuilder The “AGDD_XmlFileBuilder” tools...The “AGDD_XmlFileBuilder” tools... allow AGDD/XML files to be created as a tree in memory, rather than as a s equential output streamallow AGDD/XML files to be created as a tree in memory, rather than as a s equential output stream enforce adherence to more AGDD/XML syntax requirements than present XML checkers aloneenforce adherence to more AGDD/XML syntax requirements than present XML checkers alone allow some separation between “intent” and “output format”allow some separation between “intent” and “output format”

Where is the geometry generated? All code is available in the ATLAS offline software repository under: /afs/cern.ch/atlas/software/cvs/All code is available in the ATLAS offline software repository under: /afs/cern.ch/atlas/software/cvs/ In particular:In particular: –the SCT specific stuff is in the package: offline/InDetDetDescr/SCT_AGDD_XmlFileBuilder –while the generic tools are in the package: offline/DetectorDescription/AGDD_XmlFileBuilder

Where are we going? (1) AGDD/XML syntax is perhaps about to undergo some large changes:AGDD/XML syntax is perhaps about to undergo some large changes: –New emphasis: Detector specific elements may be introducedDetector specific elements may be introduced Possible reduction of inter-dependencies within AGDD/XML files?Possible reduction of inter-dependencies within AGDD/XML files? – New features / expectations: Level-of-detail mechanism (LeCompte et al)Level-of-detail mechanism (LeCompte et al) Envelopes (Laporte et al)Envelopes (Laporte et al) “Surnames” (Dell’Acqua et al)“Surnames” (Dell’Acqua et al) Some/all of the above may result in next version of geometry being very different from current !Some/all of the above may result in next version of geometry being very different from current !

Where are we going? (2) Physical geometry has moved on since ID-TDR. Need to update!Physical geometry has moved on since ID-TDR. Need to update! –Jo Pater is about to update existing AGE geometry to match present “best guesses” at detector configuration. – The next geometry produced within the AGDD/XML framework ought to be generated from the “same drawings” as Jo’s new AGE geometry...generated from the “same drawings” as Jo’s new AGE geometry... … but the next AGDD/XML geometry (unlike the present one) the should not be a slavish copy of AGE. The new geometry should be constructed independently. Intended result: Better AGDD/XML, and no bad habits inherited from age.… but the next AGDD/XML geometry (unlike the present one) the should not be a slavish copy of AGE. The new geometry should be constructed independently. Intended result: Better AGDD/XML, and no bad habits inherited from age. Who will do all of this ? I have to write a thesis soon …..Who will do all of this ? I have to write a thesis soon …..

Related work: SCT Modules Szymon Gadomski is firing particles through simulations of SCT modulesSzymon Gadomski is firing particles through simulations of SCT modules As a by-product this generates a test of SCT geometry within AGDD/XML and G4Builder frameworkAs a by-product this generates a test of SCT geometry within AGDD/XML and G4Builder framework

Thanks to the G4 Team! I would like to thank the Geant4 team for help and advice they have given me over the last few months in helping me solve problems with these geometries.I would like to thank the Geant4 team for help and advice they have given me over the last few months in helping me solve problems with these geometries.