Xtal Calorimeter with Fiber Readout

work by diploma student

Ralph Dollan (HU)

Achim Stahl DESY Zeuthen 10.Oct.2003

LumiCal

BeamCal

Detector Concept

segments of heavy crystals

individual fiber readoutfor every crystal segment

Expectations:• excellent energy resolution• excellent timing• reasonable segmentation• small Molière radius (?)

Test Setup

Cosmic Telescope

Alternative: Ru-Source

Calibration of PMTs

PMT

LED

Lightyield

Measure Lightyield with plastic scintillatorCompare fiber readout vs. direct readout

Lightyield

fiber readout

directreadout ~ 25 %

Cross Talk

How much light do fibers see from other crystals

fiber painted with black paint

Cross Talk

cosmics

?

but ….

Outlook

complete cross talk studies

test fiber readout for Čerenkov radiator

investigate heavy crystals

try APD readout

build larger array

but..… Ralph will finish end of this yearno further man-power available

PMT - Calibration