CBM-RICH: Photodetector developement CBM Collaboration Meeting February 2008 P.Koczoń, C.Höhne, A.Braem C.Joram, S.Ilie, M. van Stenis CBM Workshop February

CBM-RICH: Photodetector developement

CBM Collaboration Meeting February 2008

P.Koczoń, C.Höhne, A.BraemC.Joram, S.Ilie, M. van Stenis

CBM Workshop February 2008 Piotr Koczoń,GSI



Photodetector for RICH CsI – MPWC, PM Array photomultiplier: H8500, H9500

geometrical properties -> coverageoptical properties -> quantum efficiency

electronical properties -> readout, cross-talk

H8500: room for improvements:- WLS coating: technology, measurements, results- Single Photon Counting: measurement, results

Outlook/Plans


H8500

8x8 pads5.8 x 5.8 mm each89% packing densityU=1100 V butborosilicate windowand low QE for UV


Wave-length shifter

p-TerphenylpTer

TetraphenylButadiene TPB


Coating plant (theory)

Schutter

Boat

PMs

Heating

Vacuum

Quartz crystal microbalance

Material


Coating plant (reality)


Depositing pTer, TPB and YellowX

TPB pTer YellowXPM5 41 μg/cm2 63 μg/cm2

PM4 65 μg/cm2 95 μg/cm2 276 μg/cm2

PM3 92 μg/cm2

PM2 162 μg/cm2

PM1 235 μg/cm2 343 μg/cm2


QE Test Bench (HPD)- Air- 200 nm cut off- abs. QE measurement

Monochromator-Vacuum- deep UV- no absolute QE

Quantum efficiency measurements (theory)


Monochromator

QE Test Bench

Quantum efficiency measurements (reality)


PMs - Quantum Efficiencies

0

0,05

0,1

0,15

0,2

0,25

0,3

0,35

150 200 250 300 350 400 450 500 550 600 650 700

Wavelength [nm]

QE

PM1

PM2

PM3

PM4

PM5

PM1-TPB

PM2-TPB

PM3-TPB

PM4-TPB

PM5-TPB

PM1-pTer

PM4-pTer

PM5-pTer

TPB-Resin

YellowX-Evptd

YellowX-PowderPM4+QuarzGlas

QE for XP3102PRELIMINARY


QE for XP3102 coated with TPB


0

0,05

0,1

0,15

0,2

0,25

0,3

0,35

150 200 250 300 350 400 450 500 550 600 650 700

Wavelength [nm]

QE

PM1

PM2

PM3

PM4

PM5

PM1-TPB

PM2-TPB

PM3-TPB

PM4-TPB

PM5-TPB

PM1-pTer

PM4-pTer

PM5-pTer

TPB-Resin

YellowX-Evptd


PRELIMINARY


QE for XP3102 coated with pTer


0

0,05

0,1

0,15

0,2

0,25

0,3

0,35

150 200 250 300 350 400 450 500 550 600 650 700

Wavelength [nm]

QE

PM1

PM2

PM3

PM4

PM5

PM1-TPB

PM2-TPB

PM3-TPB

PM4-TPB

PM5-TPB

PM1-pTer

PM4-pTer

PM5-pTer

TPB-Resin

YellowX-Evptd


PRELIMINARY


QE for XP3102 with YellowX


0

0,05

0,1

0,15

0,2

0,25

0,3

0,35

150 200 250 300 350 400 450 500 550 600 650 700

Wavelength [nm]

QE

PM1

PM2

PM3

PM4

PM5

PM1-TPB

PM2-TPB

PM3-TPB

PM4-TPB

PM5-TPB

PM1-pTer

PM4-pTer

PM5-pTer

TPB-Resin

YellowX-Evptd


PRELIMINARY


QE for XP3102 @ far UV

IA(λ) = F(λ) * QE(λ)

R(λ) = IAwls(λ)/ IA(λ) = QEwls(λ) / QE(λ)

QEwls(λ) = R(λ) * QE(λ) = IAwls(λ)/ IA(λ) * QE(λ)


QE for XP3102 @ far UVComparison pTer / bare PM

0,00

100,00

200,00

300,00

400,00

500,00

600,00

700,00

800,00

900,00

100 150 200 250 300 350 400 450 500 550

Wavelength [nm]

Re

ala

tiv

e s

en

sit

ivit

y

PM1

PM4

PM5

PM1-pTer

PM4-pTer

PM5-pTer

for p-Ter

for TPB

Comparison_TPB-bare_PM

0,00

100,00

200,00

300,00

400,00

500,00

600,00

700,00

800,00

900,00

1000,00

100 150 200 250 300 350 400 450 500 550

Wavelength [nm]

Re

ala

tiv

e s

en

sit

ivit

y

PM1

PM2

PM3

PM4

PM5

PM1-TPB

PM2-TPB

PM3_TPB

PM4-TPB

PM5-TPB

IAwls(λ)/ IA(λ)

PRELIMINARY

PM/PM-TPB/PM-TPB-QE

0,0

0,2

0,4

0,6

0,8

1,0

150 200 250 300 350 400 450 500 550

Wavelength [nm]

Re

lati

ve

in

ten

sit

y/Q

E

PM1-QE

PM2-QE

PM3-QE

PM4-QE

PM5-QE

PM1-TPB-norm

PM2-TPB-Norm

PM3-TPB-Norm

PM4-TPB-Norm

PM5-TPB-Norm

PM1-TPB-QE

PM2-TPB-QE

PM3-TPB-QE

PM4-TPB-QE

PM5-TPB-QE


QE for XP3102 @ far UV

PM-pTer / PM-pTer-QE

0,0

0,2

0,4

0,6

0,8

1,0

1,2

150 200 250 300 350 400 450 500 550

Wavelength [nm]

Re

lati

ve

in

ten

sit

y/Q

E

PM1-QE

PM4-QE

PM5-QE

PM1-pTer-norm

PM4-pTer-Norm

PM5-pTer-Norm

PM1-pTer-QE

PM4-pTer-QE

PM5-pTer-QE

for TPB

for p-Ter

PRELIMINARY


Single photon counting capability (theory)

PM

HV

PulseGeneratorPico FADC

n grey filters

Light guide bundle

Lighttight box

LED

gate

signal


Single photon counting capability (reality)

n times grey filter

Light guide bundle

Darkbox

LED

signalPulse generator(a bad one)

HV


Single photon counting capability - results


Single photon counting capability - results

Not convincing!!! A combined pulse-amplitude - time-series analysis necessary.


Open questions:

WLS - ageing in CO2 – next measurement at CERN in June 2008- mechanical properties

Single Photon Counting - final proof for H8500

Cross-talk between neighbouring pixels (with and w/o WLS)

Readout- nXyter – April 2008- nXyter: adapter – charge divider

RICH-prototype for the test run in Fall´08


Thank You !


Documents

CBM-RICH: Photodetector developement CBM Collaboration Meeting February 2008 P.Koczoń, C.Höhne, A.Braem C.Joram, S.Ilie, M. van Stenis CBM Workshop February