1 A first design of the PEP-N Calorimeter A first design of the PEP-N Calorimeter Presented by P....

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A first design of the PEP-N Calorimeter A first design of the PEP-N Calorimeter Presented by P. Patteri

Laboratori Nazionali di Frascati INFN

for PEP-N Calorimeter Group

Brief presentation of KLOE calorimeterBrief presentation of KLOE calorimeter Schematics of PEP-N calorimeterSchematics of PEP-N calorimeter Simulations: reconstruction and TOFSimulations: reconstruction and TOF

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24 barrel modules60 cells (5 layers)

4.3m length

2 × 32 endcap modules

10/15/30 cells

2440 cells2440 cells 4880 channels4880 channels

Fiber choice: Kuraray SCSF-81 and Pol.Hi.Tech 0046

PM choice: Mesh Hamamatsu R5946

KLOE CALORIMETER OVERVIEW

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The KLOE EMC is a fine sampling lead/scintillating fibers calorimeter

Volume Ratio Fiber:Lead 50:50Energy sampling fraction 13 %<X0>= 1.6 cm <>=5.3 g/cm3

1.2 mm

Lead

1.35 mm1.0 mm

52.5 cm

15X0

430 cmPure “em” calorimeter … no compensation

High light yield and good energy resolution due to fibers’ choice

Excellent time resolution driven by fast time emission in the fibers and small light path dispersion along the fibers’ length

THE CALORIMETER STRUCTURE

N.B. the particles impinging on the calorimeter cross the fibers “almost” orthogonallyN.B. the particles impinging on the calorimeter cross the fibers “almost” orthogonally

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before photo-tubes installation

Light guides at one end of a barrel module before photo-tubes installation

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Average energy scale:

40 MeV/MIP

Using the number of pe/MIP measured at CRS: light yield of

1000 pe/GEV/side @ calorimeter center

A factor 2 more light at the calorimeter boundaries

Energy resolution dominated by sampling fluctuactions

No cuts have been made on “holes” or specific detector regions

LINEARITY IN ENERGY RESPONSE AND ENERGY RESOLUTION

e+e- e+e-

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TIMING RESOLUTION

Behaviour of t

as a function of the energy is reported using all relevant ’s samplesComparing the difference of timing between two clusters at small and large angle we estimate that of the 147 ps of constant term:

50 ps mis-calibration

55 ps bunch spread

125 ps machine time spread

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Measured efficiency in Kloe calorimeterMeasured efficiency in Kloe calorimeter

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Summary of KLOE-type SciFi calorimeterSummary of KLOE-type SciFi calorimeter

Spatial resolution transverse ~1.5 cm

  longitudinal 1.2/E cm/GeV

Energy resolution   0.06/E 1/GeV

Time resolution   54/E[GeV]+ 147 ps

Radiation length   1.5 cm

Energy sampling frac.   13 %

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Perspective view of the PEP-N calorimeterPerspective view of the PEP-N calorimeter

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Forward calorimeterForward calorimeter

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Montecarlo efficiency of 10 cm thick Montecarlo efficiency of 10 cm thick Kloe-type calorimeterKloe-type calorimeter

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Montecarlo energy resolution of 10 cm thick Montecarlo energy resolution of 10 cm thick Kloe-type calorimeterKloe-type calorimeter

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energy distributionenergy distributionFCAL, RCAL (top) BCAL, PCAL (bottom)FCAL, RCAL (top) BCAL, PCAL (bottom)

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K- K- time-of-flight difference time-of-flight difference

Delta TOF

0.00

1.00

2.00

3.00

4.00

200 300 400 500 600 700 800 900 1000 1100

Momentum [Mev/c]

De

lta

TO

F [

ns

]

kappa-pi TOF 60 cm (PCAL)+ 280 ps - 280 pskappa-pi TOF 125 cm (FCAL)+ 280 ps - 280 ps

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TOF distribution in FCAL, BCAL and PCALTOF distribution in FCAL, BCAL and PCALTitle:pepnt_12_his.epsCreator:HIGZ Version 1.26/04Preview:This EPS picture was not savedwith a preview included in it.Comment:This EPS picture will print to aPostScript printer, but not toother types of printers.

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