1. 1 Sci Fi Simulation and Reconstruction Status M.Ellis/C.Rogers Wednesday 31 st March 2004

2. 2 Status and Developments Pattern recognition follows the scheme: –Build clusters of hits (as for cosmic ray test) –Build space points (triplets only at the moment) –Build tracks (find best track in each tracker). Ongoing development in the following areas: –Reproduction of cosmic test performance –Modification of geometry/etc to match latest design. –Treatment of dE/dx in Kalman fit –Improved Pattern Recognition performance in presence of high background –General code cleanup

3. 3 Matching Cosmic Test Results Light Yield in simulation is now the same as that measured in the 5000 ppm 3HF fibre, as this is the worst case. Hit finding cut used is the same as for the cosmic analysis – 2 Photo Electrons. Simulation does not include non-linearity of VLPCs above 15 PE, however this should not be an issue, as a hit is anything above 2 PE, and the actual signal is not used.

4. 4 Light Yield (Cosmic & G4MICE) Tracker Prototype: 8.9 G4MICE: 8.7

5. 5 Modification of Geometry Fibre pitch has been increased from 420 to 427  m. Spacing of stations in Z needs to be altered due to physical constraints caused by the waveguides, however these distances have not yet been optimised, so this study still needs to be performed. Need to confirm exact thickness of material and radiation length in simulation and reconstruction descriptions.

6. 6 dE/dx in Kalman New version of the Kalman package has been provided that includes dE/dx in the propagation of states. First version of the tracking code in G4MICE using this is currently undergoing testing. Hope to release new Kalman and corresponding Sci Fi code by the end of the Software Workshop.

7. 7 Future Improved Performance Under very high backgrounds, the Pattern Recognition still works well, but slowly due to the number of combinations tested. Currently modifying the pattern recognition to remove bad combinations of hits/points and outliers as early as possible. In addition, code has a lot of copies (objects being passed by copy, rather than reference or pointer) – this is being cleaned up as part of the overall design iteration process.

8. 8 Momentum Resolution with first version of dE/dx

9. 9 General Code Clean-up Due to hurried nature of development over the past 12-18 months, a lot of classes are less efficient than they could be, with wasteful loops, copies, etc. Design Iteration process for the Sci Fi code will include a complete look at the classes needed for the Sci Fi and how they should interact. This clean-up process has already been started in parallel with the higher level studies.

10. 10 Conclusions Progress is being made, but slowly. Performace of tracker in cosmic ray test stand has been propagated to the simulation. First version of the track fit with dE/dx is now running and being debugged. Further improvements in physics performance and CPU/memory use expected following code clean- up and design iteration. As is true for any aspect of the software effort, anyone who wants to help is very welcome, please talk to Yagmur, or the relevant package manager.