first results from EMCal test beam
Delia Hasch the EMCal case jet physics: fast trigger for high pT jets, g (p0), e-
TPC PHOS TRD RICH EMCal support structure TOF back-to-back to PHOS acceptance: -0.7 < h < 0.7; Df = 110 granularity ~12k channels tower: Dh x Df ~ x 0.014 energy resolution ~10%/E highly improves jet reconstruction good g/p0 discrimination direct pT good e/h discrimination heavy quark pT EMCal module low cost sampling calorimeter
time schedule modular option Al Pb Steel Scint. Fiber. geometry: trapezoidal - projective single tower: 6x6x25 cm3 1 module: 4 towers technology: sampling calorimeter: 1.76 mm scint 1.44 mm Pb 77 layers for total of 20 X0 light readout shashlik, 36.7cm wave length shifter fiber APD+CSP readout, FEE adopted from TPC and PHOS EMCal structure animate EMCal readout APD test station:
PHOSreadout electronics adopted (APD: Avalanche Photo Diode) APD test station: determine APD gain dependence on bias voltage measure gain dependence on operation temperature evaluate nominal voltage setting for gain M=30 APD test station @Catania
[GRAZIE al gruppo di Catania, Paola La Rocca] standard EMCal electronic chain light from LED flasher fluid from a chiller at fixed temperature APD test results from Catania
[GRAZIE al gruppo di Catania, Paola La Rocca] first sample of 80 APDs analysed for test beam start test activities for mass production module assembly @LNF final module design + electronics chain
EMCal test beam sept/oct 2007 @cern SPS/PS module final module design + electronics chain assembly station scintillator tile lead tile 350 kg pressure wrapping final module module assembly @LNF 4 ministrips of 4 modules: 2 from LNF
EMCal test beam sept/oct 2007 @cern SPS/PS module 4 ministrips of 4 modules: 2 from LNF 2 from WSU WLS insertion strongback fixed goals energy and position resolution
EMCal test beam sept/oct 2007 @cern SPS/PS goals energy and position resolution linearity + uniformity of energy response shower shapes for electrons and hadrons develop calibration tools (gain stability, time dependence) SPS PS e-: (5) GeV p : GeV e-/p: (0.5)1-6 GeV EMCal test beam sept/oct 2007
@cern SPS/PS setup setup @SPS e- p calo EMCal test beam sept/oct 2007 @cern SPS/PS Sc1,2
5-100 GeV e- calo DC delay (beam diagnostics) movable platform p GeV Sc1,2 position energy energy scan hadron beam reference measurm.s tilted configurations beam size ~1 cm2 momentum spread ~1% rms event display LED pulses: EMCal test beam sept/oct 2007 @cern SPS/PS
4x4 modules: 8x8 towers LED pulses: ADC vs time-sample# tower-by-tower differences due to different layout for LED installation LED pulser monitor stability of gain event display e- beam: EMCal test beam sept/oct 2007 @cern SPS/PS
4x4 modules: 8x8 towers e- beam: ADC vs time-sample# different positions different energies tilts hadron beam data analysis EMCal test beam sept/oct 2007 @cern SPS/PS DAQ :
pcemcal001 DATE for EMCal readout online checks (aliroot plotting macros) tape storage + analysis: CASTOR CASTOR tape storage; registered in AliEn not yet AliRoot official area: AliRoot/AliEn reco Calib parameters still hard-coded to be moved to OCDB Rawdecoder: unpack logic, pedestal calc+subtraction, fitting procedure implemented for energy estimate from raw signal DigiProducer: switches gain logic: high low gain respectively to low / high incident energy mapping calibration parameters like gains, temperature info, ecc. OCDB CAF analysis [AliEMCALRawDecoder, AliEMCALRawDigiProducer, ] [thanks to Marco v.L., David S., Boris P., a.o.] energy reconstruction
EMCal test beam sept/oct 2007 @cern SPS/PS energy reconstruction full AliEn reconstruction chain 80 GeV position 80 GeV position Ereconstructed [GeV] Ereconstructed [GeV] !caveats: preliminary calibation, beam momentum spread not unfolded energy reconstruction
EMCal test beam sept/oct 2007 @cern SPS/PS energy reconstruction full AliEn reconstruction chain 80 GeV position linearity off by factor 1.2 Ereconstructed [GeV] !caveats: preliminary calibation, beam momentum spread not unfolded position scan: uniformity
EMCal test beam sept/oct 2007 @cern SPS/PS position scan: uniformity 80 GeV incident beam energy 68.5 0.4 !caveats: preliminary calibation, beam momentum spread not unfolded energy resolution !caveats: preliminary calibation,
EMCal test beam sept/oct 2007 @cern SPS/PS energy resolution full AliEn reconstruction chain single-particle simulation VERY PRELIMINARY @fixed position !caveats: preliminary calibation, beam momentum spread not unfolded energy resolution !caveats: preliminary calibation,
EMCal test beam sept/oct 2007 @cern SPS/PS energy resolution full AliEn reconstruction chain VERY PRELIMINARY @fixed position test !caveats: preliminary calibation, beam momentum spread not unfolded summary & outlook ready to start production of EMCal
test with final module design and readout electronics energy resolution over wide momentum range position resolution linearity + uniformity of energy response shower shape analysis for electrons and hadrons usage of official Ali-online+offline tools with real data (DATE, monitoring tools; CASTOR for tape storage; AliEn for offline analysis) cosmics calibration of modules just started reference relative energy calibration ready to start production of EMCal