FT Prototype Test Purpose: test the prototype of the FT Calorimeter and Scintillator Hodoscope Technique: prototype is installed under the Hall B photon tagger and aligned with the electron trajectories FT Calorimeter Determine the energy resolution at different energies as a function of threshold and operating temperature Determine the timing resolution Test the fADC readout (energy reconstruction and timing measurement) Study the electromagnetic shower profile FT Hodoscope Determine the timing resolution Compare the performances of different geometries and number of WLS fibers Study the resolution and noise dependence on threshold and distance from the calorimeter (splashback) Test the fADC readout

Test Setup Ebeam=2.282 GeV E~1.31 GeVE~0.75 GeV E~0.15 GeV

Test Setup VME-based readout with fADCs, discr. and TDCs CODA-based DAQ Cooling lines Nitroge n lines Hodoscop e Prototype Plastic Scintillato r

Calorimeter Prototype 3x3 matrix of PbWO-II crystals (15x15x200 mm3) Copper case acts as thermal shielding Coolant liquid circuit (-25C C) APD based readout (10x10mm2 Hamamatsu S ) Preamplifiers developed by IPM Orsay Motherboard to distribute HV and LV and collect signals 5 cm thick insulation Plastic containment box

Hodoscope Test Module WLSF in light proof Plastic sleeve Scintillator tile mounted In line with centre of calorimeter Lightproof box containing 3x3mm SiPMT and prototype amplifier D. Watts (U. Edinburgh)

Hodoscope Test Module 2 Kuraray WLS Fibre Hamamatsu 3x3mm SiPMT Prototype amplifier module Test module currently connected to 15x15 mm EJ204 Tile, 1cm thick. 2 embedded WLSFs of ~1m length Also have 30x30mm 5mm thick EJ204 read with 4 WLSFs. Also long WLSF (~5m) Signal obtained in the hall D. Watts (U. Edinburgh)

Temperature Control PRIMEX Chiller with Glycol T: C Agilent Temperature Data logger Temperature (C)

Status & Run Plan FT prototype installed in the Hall and fully operational: Gas and cooling system tested HV for calorimeter APDs, hodoscope SIPM and PMT connected and functional Standalone DAQ operational and first data have been collected Initial alignment of the prototype done during last access, more precise alignment based on data analysis is in progress Run Plan: continue data taking in present position to complete alignment and fully debug the system repeat measurement in different position along the tagger to determine the prototype response at different energy repeat measurements at different temperature to determine the temperature dependence of the resolution replace hodoscope tile with other samples and repeat measurements extend the energy scan at higher values after pass change (end of January)

First Signals