1. Preshower/Crack Upgrade Update 2005-02-10 1.Detector overview 2.W electron data 3.Simulation overview 4.Early tests of new simulation

2. Preshower/Crack Detectors

3. NEW EMPTY, EM Calorimeter face OLD Installation configuration

4. 0123456789 Central Crack Detectors behind 8 X 0 Tungsten bar More Gas Proportional Chambers with slow response Gas Proportional Chambers with slow response Central Preshower Previous gas detectors New scintillator pad detectors

5. CPR2 Overview 24x2 Wedges Scintillator tiles  Total n. of channels= 3,072  CPR: 12.5x12.5x2 cm single tile  ~ 810 Liters of scintillator  CCR: 22.5x5x0.5 cm single tile Photomultipliers  16 channels per PMT (H6568)  192 HV channels  CAEN HV SY527 Preshower Detector (CPR) Wedge Total CPR54 2,592 CCR10 480  CPR segmentation = 2x3 (  ) /tower  64 channels/wedge, exactly 2 SMD cards per wedge, to reuse present electronics  WLS fiber into groove, spliced to clear fiber at tile exit, routed to optical connector Crack Detector (CCR) CPR Tile

6. Random Tracks vs W electrons DATA Data performance very good, 0.1% dead channels. Should lead to simple geometry in simulation.

7. Simulation overview Jun Suh is the main developer. Simulation of old detector was only used for 1 plot! (slight exaggeration) How often does at least one of the two photons from a  ° give a 1 MIP hit? Analyses with electrons used data for all studies. Conversions, Kshort…

8. Simulation is convolution of MIP histogram with Nmips from Geant.

9. This simple prescription worked well with old detector and test beam data.

10. Simulation overview These curves depend on geometry and decay kinematics, not much more. Geometry looks good in new simulation. Not very sensitive to precise pulse height, with a 0.5 – 1 MIP cut. Simulated CPR2 Pulse Heights for 40 GeV Photons.

11. But how does it look for CPR2 so far?? Need a full W simulation with cuts applied, not single particles shot at one location and Pt. Also need input muon pulse height distribution instead of pions…

12. Simulation review CPR2 geometry is in and checked Run number switch works, >190000 gets new detector Approximate CPR2 MIP pulse height distribution installed using pions, hopefully input muons within 2 weeks. At this point simulation should be as good as old detector. Longer term, significant interest in ANL and Korean groups to redo charged pion simulations to get CEM/CES/CPR correlations. This will help detailed electron/tau/jet studies.