CDF Aug. 20th, 2000 1 Scintillation counters for the CDF Muon Upgrade DPF 2000, Columbus Ohio G. Pauletta, for the CDF Collaboration Outline : Overview upgrade objectives and the role of the scintillation counters The Run I counters Characteristics, performance and problems Filling the holes and extending the coverage: New counters design and performance Refurbishing old counters method and results
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Scintillation counters for the CDF Muon Upgrade DPF 2000, Columbus Ohio
Scintillation counters for the CDF Muon Upgrade DPF 2000, Columbus Ohio G. Pauletta, for the CDF Collaboration. Outline : Overview upgrade objectives and the role of the scintillation counters The Run I counters Characteristics, performance and problems - PowerPoint PPT Presentation
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CDF
Aug. 20th, 2000 1
Scintillation counters for the CDF Muon Upgrade
DPF 2000, Columbus OhioG. Pauletta, for the CDF Collaboration
Outline:Overview
upgrade objectives and the role of the scintillation counters
The Run I countersCharacteristics, performance and problems
Filling the holes and extending the coverage: New countersdesign and performance
Refurbishing old countersmethod and results
CDF
Aug. 20th, 2000 2
Muon Upgrade objectives
Trigger on muons at increased luminosity ( >1032) and shorter bunch crossings (396 ns, 132 ns) Increase coverage
RUN I -------- > RUN II
CMU CMP/CSP CMX/CSX BMU/BSUCoverage 0<<0.6 0<<0.6 0.6<<1 1<<1.5drift time 800 ns 1.4 s 1.4 s 800 ns
Scintillator: UPS-923A from Monokristal, Kharkov, Ukraine. Polystyrene doped with PTP(2%) and POPOP(.03%)
Ctr. type number dimensions
CSP 150 320cm x 30.5cm x 2 cmBSU 432 164 cm x 17 cm x 1.5 cm
Wls fiber: double - clad Y11 fiber from Kuraray fiber “mirrored at far end.
Hamamatsu H5783 photomultiplier + Cockroft - walton base
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Aug. 20th, 2000 7
Counter readout
Wls fiber
PAD
CDF
Aug. 20th, 2000 8
New counter assembly
PAD
LED
LED
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Aug. 20th, 2000 9
Counter output calibration
Each counter output is calibrated in absolute terms (number of photoelectrons/ADC channel) by exposing it to low - level pulsed light ( ~1 p.e./pulse) and locating the centroid single p.e. distribution.
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Aug. 20th, 2000 10
Counter response ( in photoelectrons) to cosmic muonsis measured in steps of ~20 cm and the results are fittedto extract counter characteristics
Measurements are automated (4 ctrs at a time)Offline fit
npe(x) = n0(exp(-x/l) + r * exp(-(2L -x)/l))From the fit , one extracts:n0 (zero extrapolation)r (reflection coefficient of fiber mirrors)keeping known fiber attenuation constant at 3 m
npe
distance (x) from pmt
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Aug. 20th, 2000 11
RUSSIAN L3 COUNTER ASSEMBLY AND TEST RECORDSLum gain at gain at LED
L3 n pe at PMT sens 800 v 950 v Attenuation measurement PLATEAU AMPL at
counter 315 cm s/n E-05 E+05 E+06 n 0 nend r nend' EAST WEST PAD # Voltage PLATEAU