Preshower/Crack Upgrade Update 2005-02-10

1. Detector overview

2. W electron data

3. Simulation overview

4. Early tests of new simulation

Preshower/Crack Detectors

Preshower/Crack Detectors

NEW

EMPTY, EM Calorimeter face

OLD

Installation configuration

0 1 2 3 4 5 6 7 8 9

Central Crack Detectors behind 8 X0

Tungsten bar

More Gas Proportional Chambers with slow response

Gas Proportional Chambers with slow response

Central Preshower

Previous gas detectors

New scintillator pad detectors

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

12.5 cm

12.5 cm

2cm

Splicing WS/CF

~5 m

Preshower Detector (CPR)

Wedge Total

CPR 54 2,592

CCR 10 480

CPR segmentation = 2x3 () /tower64 channels/wedge, exactly 2 SMD cards per wedge, to reuse present electronicsWLS fiber into groove, spliced to clear fiber at tile exit, routed to optical connector

Crack Detector (CCR)

CPR Tile

Random Tracks vs W electrons DATA

Data performance very good, 0.1% dead channels. Should lead to simple geometry in simulation.

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…

Simulation is convolution of MIP histogram with Nmips from Geant.

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

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.

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…

Simulation reviewCPR2 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.