1. ALFA GeoModel implementation and simulation status  ATHENA, what is our job?  ALFA GeoModel implementation  MC simulation – first steps  Problems  Summary Vít Vorobel ALFA meeting CERN 24.5.2006

2. Vít VorobelALFA meeting CERN 24.5.20062 ATHENA network  DATA  Materials  Geometry (GeoModel) o Tile Cal o SCT o ALFA  we have to provide to ATLAS o …  Settings  …  TOOLS  Simulation (GEANT)  we may use for ALFA  Analysis (Root)

3. Vít VorobelALFA meeting CERN 24.5.20063 23.17 135 160 173 270 ALFA Si-1 PS Si-2 Si-3 GeoModel - Geometry & materials Si-1,2,3 – Si,  = 2.3g/cm 3, 0.3x100x100mm PS – Polystyrene (C 8 H 8 ) n,  =1.05g/cm 3,8x16x12mm Air – 20%O 2, 80%N 2,  = 1.29mg/cm 3 ALFA detector Ceramics – Al 2 O 3,  =3.7g/cm 3, 0.17x16x12mm Plastic layers – material as PS, 0.5x16x12mm, logically divided to –Sensitive cores of fibers □0.48 mm –Insensitive everything else simulating cladding, glue, and spacers –Fibers positioned regulary with x and pinch from metrology data, slope=45° –Fibers are not cutted on the edge.

4. Vít VorobelALFA meeting CERN 24.5.20064 MC simulation  A testing volume built and a particle shouted from IP to the volume  Deposited energy evaluated end histogrammed

5. Vít VorobelALFA meeting CERN 24.5.20065 Problems  All components of the ATHENA framework are under development  New versions of the components are released independently – are not compatible  E.g.  version…&version…  histograms are not built  V….&v….  histohrams are built but not visible  V….&v….  segmentation fault .  Users (we) never know if the user code is wrong or the used components are not compatible

6. Conclusion  Achievements  GeoModel – The present code includes  The ALFA and Overlap detectors with ideal fiber staggering  The detectors are “cloned” to all stations  MC Simulation – we are able  to shout a particle into a testing volume  To read and histogram the energy deposition in the testing volume  Tasks to do  Add Roman Pots to GeoModel  Learn how to read a real geometry from the database  Learn how to modify ideal  real geometry in GeoModel  Ask an administrator to add our code to ATHENA framework  Extend MC simulation from a testing volume to ALFA detector