the fast photon detection system of compass rich-1 · vienna, 23/02/2007 - the 11th vienna...

Fulvio TESSAROTTOFulvio TESSAROTTOVienna, 23/02/2007 Vienna, 23/02/2007 -- The 11th Vienna Conference on InstrumentationThe 11th Vienna Conference on Instrumentation 11

Sezione di TriesteSezione di Trieste

THE FASTTHE FAST PHOTON DETECTIONPHOTON DETECTIONSYSTEM OFSYSTEM OF COMPASS RICHCOMPASS RICH--11

COMPASS RICH-1

The motivations for the upgrade

The project and the construction

The preliminary performancesduring 2006 run

Fulvio Tessarottoon behalf of the COMPASS RICH Upgrade Group



SM1 dipoleSM1 dipole

SM2 dipolePolarised Target

HCAL1

Muon-filter1,MW1

Micromegas,DC,SciFi

Gems,SciFi,DCs,straws

MWPC Gems Scifi

trigger-hodoscopes

Silicon

THE COMPASS SPECTROMETERTHE COMPASS SPECTROMETER

RICH_1

BMS

Gem_11

ECAL2,HCAL2

straws,MWPC,Gems,SciFi

strawsMuon-filter2,MW2

DW45

SciFi

Veto

Beam:160 GeV µ+

2 . 108 µ/spill(4.8 s/16.8s)Pμ ~ 80%



COMPASS RICHCOMPASS RICH--11

requirements:requirements:

hadronhadron PID up to ~45 PID up to ~45 GeV/cGeV/cLARGE acceptance (large size): LARGE acceptance (large size):

H: 500 H: 500 mradmradV: 400 V: 400 mradmrad

able to stand trigger rates able to stand trigger rates up to 20 KHzup to 20 KHzbeam rates up to 4beam rates up to 4··101077 HzHzminimize material in the minimize material in the acceptanceacceptance

detector designed in 1996detector designed in 1996

PROJECT COST : ~ 3 M PROJECT COST : ~ 3 M €€

radiator:radiator:CC44FF1010

5 m5 m

6 m6 m3 m3 m

photon photon detectors:detectors:CsICsI MWPCMWPC

mirrormirrorwallwall

vesselvessel

radiator:radiator:CC44FF1010

detection of detection of VUVVUV photonsphotons(165(165--200 nm)200 nm)

Trieste: INFN, Univ. & ICTP,Trieste: INFN, Univ. & ICTP,Turin: INFNTurin: INFN and University,and University,Bielefeld University, Bielefeld University, CERN technicalCERN technical supportsupport

CsI: 5.3 m2, 83000 pads



COMPASS RICHCOMPASS RICH--1 performances1 performances

π

K

p

E. Albrecht et al, NIM A 33 (2003) 127 E. Albrecht et al, NIM A 553 (2005) 215

RICHRICH--1 is in operation1 is in operationat COMPASS at COMPASS

since 2001since 2001

•• photons / ring (photons / ring (β β ≈≈ 1, complete ring 1, complete ring in acceptance) :in acceptance) : 14

•• σσθθ--phph (β ≈≈ 1) : 1.2 mrad

• σσringring (β ≈≈ 1) : 0.6 mrad

• 2σ π-K separation @ 43 GeV/c

• PID efficiency > 95%(θ Ch > 30 mrad)except for the very forward region



RICHRICH--1: experimental challenges1: experimental challengesTHE EXPERIMENTAL ENVIRONMENTTHE EXPERIMENTAL ENVIRONMENT

huge uncorrelated backgroundrelated to the memory of theMWPCs + read-out

THE HIGH RATE OPERATIONTHE HIGH RATE OPERATIONIncreased beam intensity:

ultimate goal 100 MHzpresently: 40 MHz

Increased trigger ratesup to 100 KHzpresently: 20kHz

No dead time (Luminosity)

overlap of overlap of event imagesevent imagesμμ beambeam



12 outer CsI cathodes: change electronics, use APV25-S1 chip4 central CsI cathodes: remove and insert frames with MAPMTs

and lense telescopeskeep mechanical compatibility, build (and test) 4 new anodes

with “half-wires”

wires

no wires

new anodesnew anodes

Same mechanics Same mechanics as as CsICsI photophoto--cathode framecathode frame

RICHRICH--1: the upgrade1: the upgrade

using using MAPMTsMAPMTs



Outer region: the APV25-S1 r/o electronics

peaking time: ~ 300 ns

No dead time up to 80 kHz trigger rate

3 samples read for each hit to get signal timing

Signal time :

APV25S1 developed for CMS u-strip silicon detectors

Main characteristics of the APV25-S1:128 channels / chippre-amplifier and shaper with adjustable time constants in a wide

range 50-300 ns40 MHz sampling on 192 cells analog pipeline

T = a1/a2 * 156.25 – TCS_phase

Each APV chip is glued and bonded onto a small PCB (module)Each front-end board read 432 channels (4 APV modules)One ADC card reads 4 FE boardsTotal of 62208 channels



Central region: the principleCentral region: the principlePhoton detectors : MAPMTPhoton detectors : MAPMT

wide wavelength rangetime resolution < 1 nsecshort detection system memory (MAPMT + read-out)adequate for high rate operation – up to which rate ?robustefficiency for single photon detection ?

photonsphotons

MAPMTMAPMT

concentratorconcentrator

field lensfield lens

C4F10: (n-1)*10^6

1200

1300

1400

1500

1600

1700

1800

0 100 200 300 400 500 600 700 800

lambda (nm)

(n-1

)*10

^6

C4F10CsI rangeMAPMT range

challenges:challenges:large ratio of the collection and photocathodeareas with minimal image distortion

ratio = 7.3 critical LENS SYSTEM designUV range fused silica LENSEScouple to a read-out system able to guaranteeefficiency, high rate operation and to preservetime resolution



16 anodesUV extended

glasstime resolution

~ 0.3 nsec

recall:recall:effective QE including effective QE including window losses window losses

(collection efficiency not included)(collection efficiency not included)

home made voltage dividerhome made voltage divider

FE cards plugged FE cards plugged directly heredirectly here

protects against protects against B B ≤≤ 200 G200 Gand guaranteesand guaranteesgood alignmentgood alignment

MAPMT: HAMAMATSU MAPMT: HAMAMATSU R7600R7600--0303--M16M16



UV EXTENTED UV EXTENTED IS BETTERIS BETTER

200 300 400 500 600 7000,00

0,05

0,10

0,15

0,20

0,25

0,30

0,35

0,40

S [a

.u] *

T [1

] * Q

E [a

.u.]

wavelength [nm]

Convolution of Cherenkov light and effective QE

-if no reflection-with a monolayer of MgF2-w/o antireflective layer

and even better withantireflective coating: 8.4% more photons

200 250 300 350 400 450 500 550 600 650 7000

20

40

60

80

100100

0

f x( )

ifit x( )

740200 x

g , y p y

%]

Fused Silica

Borosilacete glass

Polymer lenses

200 400 600 200 400 600 λλ(nm(nm))

frac

tion

of p

hoto

ns d

etec

ted

frac

tion

of p

hoto

ns d

etec

ted

0

0

.5

1 0

0.5

1

even better with new MAPMT UV borosilicate

λλλλλλλ

dSQEdSQE ∫∫ ⋅⋅⋅800

200

800

)()()()(



THE FUSED SILICA LENS TELESCOPETHE FUSED SILICA LENS TELESCOPE

OPTIMISATION CRITERIAOPTIMISATION CRITERIAlimited image distortionslimited image distortions

RICH resolution RICH resolution (chromaticity is taken (chromaticity is taken

into account)into account)angular acceptanceangular acceptanceof the telescopeof the telescopemechanical constrainsmechanical constrainsmanifacturingmanifacturing parameters parameters (feasibility, (feasibility, costcost!!!)!!!)

spherical s.spherical s.

planar s.planar s.

asphericalaspherical s.s.

centre edgecentre edge

spot

siz

e,

spot

siz

e, rm

srm

s(m

m)

(mm

)

0.

1

.

2

.

0.

1

.

2

.

AXIS TILT: 5 AXIS TILT: 5 ºº

ANGULAR ACCEPTANCE: ANGULAR ACCEPTANCE: ±± 9.5 9.5 ºº 220 nm220 nm

chromchrom..300 nm300 nm

400 nm400 nm600 nm600 nm



FUSED SILICA LENSESFUSED SILICA LENSES

materialmaterial: fused silica, Corning : fused silica, Corning 7980, 7980, standard grade F5standard grade F5

concentratorconcentrator

asphericasphericsurfacesurface

photons

photons

MAPMT

MAPMT

concentrator

concentrator

field lens

field lens

field lensfield lens

complex and delicatecomplex and delicatemechanical machiningmechanical machining



OPTICS QUALITY CONTROLOPTICS QUALITY CONTROLTHE THE HARTMANN METHODHARTMANN METHOD

image centroide Theoretical referenceHe-Na

laser

632 nm

optical systemunder test

Lens focus

Detected Image (CCD camera)Hartmann

plate

for parallel light

1. the principle1. the principle

2. the images2. the images

xΔ

yΔ

Zernike polynomials

3. the analysis3. the analysis

tolerance (= center points +/- 0.1 mm)

Deviations from ideal surface



576 TELESCOPES:

A) ~70% within 50 µm toleranceB) ~20% within 100 µm toleranceC) ~10% within 150 µm tolerances

A

C

B

OPTICS, THE ACHIEVEMENTSOPTICS, THE ACHIEVEMENTS



High Voltage850 900 950

Cha

rge

in p

C

0

1

2

3

4

5

6

7

Gain of PMT channel 2 / ndf 2c 0.01876 / 3Constant 0.3789± -5.986 Slope 0.0004047± 0.007774

/ ndf 2c 0.01876 / 3Constant 0.3789± -5.986 Slope 0.0004047± 0.007774

Gain of PMT channel 2

measured @ 360 nm

MAPMT MAPMT QQuality uality CControlontrol620 620 MAPMTsMAPMTsless than 10 MAPMT not fully less than 10 MAPMT not fully satisfactory (mainly: too high satisfactory (mainly: too high dark current dark current –– we require:we require:I I darkdark < 2 < 2 nA/chnA/ch after after ½½ h in dark h in dark environmentenvironment))

PROTOCOL PROTOCOL –– 2 h / MAPMT2 h / MAPMT

Visual Inspection (Pixel grid o.k.)Visual Inspection (Pixel grid o.k.)Noise rates and dark currentNoise rates and dark currentScope Image storedScope Image storedSignal shape, uniformity, gainSignal shape, uniformity, gain

measuring ADC distribution @ several Voltages

Quantum efficiencyQuantum efficiencymeasurement with blue LED and UV LED

Sun Sep 11 10:54:25 2005

20 40 60 80 100 120 140 160 180 200 220 2400

10

20

30

40

50

60

70

80

90

H6568 ADC Kanal 0 adc0Entries 250000Mean 93.84RMS 40.04Underflow 0Overflow 0

/ ndf c 197.6 / 191Prob 0.3565p0 1.34± 38.49 p1 0.96± 39.72 p2 1.34± 20.52 p3 1.38± 67.28 p4 0.7± 113.5 p5 0.56± 25.29

H6568 ADC Kanal 0

h6568_led360nm_950V.asc iiSun Sep 11 10:54:25 2005

adc0Entries 250000Mean 93.84RMS 40.04Underflow 0Overflow 0

/ ndf c 197.6 / 191Prob 0.3565p0 1.34± 38.49 p1 0.96± 39.72 p2 1.34± 20.52 p3 1.38± 67.28 p4 0.7± 113.5 p5 0.56± 25.29

20 40 60 80 100 120 140 160 180 200 220 2400

10

20

30

40

50

60

70

80

90


/ ndf c 197.6 / 191Prob 0.3565p0 1.34± 38.49 p1 0.96± 39.72 p2 1.34± 20.52 p3 1.38± 67.28 p4 0.7± 113.5 p5 0.56± 25.29


/ ndf c 197.6 / 191Prob 0.3565p0 1.34± 38.49 p1 0.96± 39.72 p2 1.34± 20.52 p3 1.38± 67.28 p4 0.7± 113.5 p5 0.56± 25.29


20 40 60 80 100 120 140 160 180 2000

10

20

30

40

50

60

70

80

H6568 ADC Kanal 1 adc1Entries 250000Mean 88.75RMS 39.19Underf low 0Overflow 0

/ ndf c 184.8 / 177Prob 0.329p0 1.23± 30.97 p1 1.69± 30.95 p2 2.74± 21.54 p3 1.16± 52.97 p4 1.4± 104.6 p5 0.92± 29.32

H6568 ADC Kanal 1


adc1Entries 250000Mean 88.75RMS 39.19Underf low 0Overflow 0

/ ndf c 184.8 / 177Prob 0.329p0 1.23± 30.97 p1 1.69± 30.95 p2 2.74± 21.54 p3 1.16± 52.97 p4 1.4± 104.6 p5 0.92± 29.32

20 40 60 80 100 120 140 160 180 2000

10

20

30

40

50

60

70

80


/ ndf c 184.8 / 177Prob 0.329p0 1.23± 30.97 p1 1.69± 30.95 p2 2.74± 21.54 p3 1.16± 52.97 p4 1.4± 104.6 p5 0.92± 29.32


/ ndf c 184.8 / 177Prob 0.329p0 1.23± 30.97 p1 1.69± 30.95 p2 2.74± 21.54 p3 1.16± 52.97 p4 1.4± 104.6 p5 0.92± 29.32


20 40 60 80 100 120 140 160 180 2000

20

40

60

80

100

120

140

160

180

H6568 ADC Kanal 2 adc2Entries 250000Mean 83RMS 31.09Underf low 0Overflow 0

/ ndf c 212.1 / 176Prob 0.03287p0 1.30± 40.82 p1 6.91± 24.79 p2 3.11± 51.37 p3 2.4± 112.8 p4 0.43± 96.39 p5 0.36± 17.63

H6568 ADC Kanal 2


adc2Entries 250000Mean 83RMS 31.09Underf low 0Overflow 0

/ ndf c 212.1 / 176Prob 0.03287p0 1.30± 40.82 p1 6.91± 24.79 p2 3.11± 51.37 p3 2.4± 112.8 p4 0.43± 96.39 p5 0.36± 17.63

20 40 60 80 100 120 140 160 180 2000

20

40

60

80

100

120

140

160

180

adc2Entries 250000Mean 83RMS 31.09Underf low 0Overflow 0

/ ndf c 212.1 / 176Prob 0.03287p0 1.30± 40.82 p1 6.91± 24.79 p2 3.11± 51.37 p3 2.4± 112.8 p4 0.43± 96.39 p5 0.36± 17.63

H6568 ADC Kanal 2 adc2Entries 250000Mean 83RMS 31.09Underf low 0Overflow 0

/ ndf c 212.1 / 176Prob 0.03287p0 1.30± 40.82 p1 6.91± 24.79 p2 3.11± 51.37 p3 2.4± 112.8 p4 0.43± 96.39 p5 0.36± 17.63


20 40 60 80 100 120 140 160 180 2000

20

40

60

80

100


/ ndf c 190.3 / 168Prob 0.1149p0 1.23± 32.59 p1 2.31± 28.96 p2 4.50± 24.72 p3 1.7± 85.7 p4 1.0± 101.6 p5 0.55± 23.18

H6568 ADC Kanal 3



/ ndf c 190.3 / 168Prob 0.1149p0 1.23± 32.59 p1 2.31± 28.96 p2 4.50± 24.72 p3 1.7± 85.7 p4 1.0± 101.6 p5 0.55± 23.18

20 40 60 80 100 120 140 160 180 2000

20

40

60

80

100


/ ndf c 190.3 / 168Prob 0.1149p0 1.23± 32.59 p1 2.31± 28.96 p2 4.50± 24.72 p3 1.7± 85.7 p4 1.0± 101.6 p5 0.55± 23.18


/ ndf c 190.3 / 168Prob 0.1149p0 1.23± 32.59 p1 2.31± 28.96 p2 4.50± 24.72 p3 1.7± 85.7 p4 1.0± 101.6 p5 0.55± 23.18


20 40 60 80 100 120 140 160 180 200 2200

20

40

60

80

100

120

140

160


/ ndf c 220.8 / 198Prob 0.1276p0 1.41± 49.18 p1 2.23± 28.74 p2 3.7± 27.7 p3 2.2± 129 p4 0.7± 105.5 p5 0.44± 22.65

H6568 ADC Kanal 4



/ ndf c 220.8 / 198Prob 0.1276p0 1.41± 49.18 p1 2.23± 28.74 p2 3.7± 27.7 p3 2.2± 129 p4 0.7± 105.5 p5 0.44± 22.65

20 40 60 80 100 120 140 160 180 200 2200

20

40

60

80

100

120

140

160


/ ndf c 220.8 / 198Prob 0.1276p0 1.41± 49.18 p1 2.23± 28.74 p2 3.7± 27.7 p3 2.2± 129 p4 0.7± 105.5 p5 0.44± 22.65


/ ndf c 220.8 / 198Prob 0.1276p0 1.41± 49.18 p1 2.23± 28.74 p2 3.7± 27.7 p3 2.2± 129 p4 0.7± 105.5 p5 0.44± 22.65


20 40 60 80 100 120 140 160 180 200 2200

20

40

60

80

100

120


/ ndf c 195.1 / 183Prob 0.2571p0 1.37± 37.89 p1 1.93± 26.58 p2 2.72± 20.49 p3 1.65± 99.38 p4 0.70± 98.51 p5 0.48± 25.27

H6568 ADC Kanal 5



/ ndf c 195.1 / 183Prob 0.2571p0 1.37± 37.89 p1 1.93± 26.58 p2 2.72± 20.49 p3 1.65± 99.38 p4 0.70± 98.51 p5 0.48± 25.27

20 40 60 80 100 120 140 160 180 200 2200

20

40

60

80

100

120


/ ndf c 195.1 / 183Prob 0.2571p0 1.37± 37.89 p1 1.93± 26.58 p2 2.72± 20.49 p3 1.65± 99.38 p4 0.70± 98.51 p5 0.48± 25.27


/ ndf c 195.1 / 183Prob 0.2571p0 1.37± 37.89 p1 1.93± 26.58 p2 2.72± 20.49 p3 1.65± 99.38 p4 0.70± 98.51 p5 0.48± 25.27


50 100 150 200 2500

20

40

60

80

100

120

140


/ ndf c 259.3 / 218Prob 0.02898p0 1.47± 46.98 p1 1.13± 34.57 p2 1.94± 22.74 p3 1.6± 108.2 p4 0.7± 115.8 p5 0.47± 27.87

H6568 ADC Kanal 6



/ ndf c 259.3 / 218Prob 0.02898p0 1.47± 46.98 p1 1.13± 34.57 p2 1.94± 22.74 p3 1.6± 108.2 p4 0.7± 115.8 p5 0.47± 27.87

50 100 150 200 2500

20

40

60

80

100

120

140


/ ndf c 259.3 / 218Prob 0.02898p0 1.47± 46.98 p1 1.13± 34.57 p2 1.94± 22.74 p3 1.6± 108.2 p4 0.7± 115.8 p5 0.47± 27.87


/ ndf c 259.3 / 218Prob 0.02898p0 1.47± 46.98 p1 1.13± 34.57 p2 1.94± 22.74 p3 1.6± 108.2 p4 0.7± 115.8 p5 0.47± 27.87


20 40 60 80 100 120 140 160 180 2000

20

40

60

80

100

120

140

160H6568 ADC Kanal 7 adc7

Entries 250000Mean 79.55RMS 33.73Underflow 0Overflow 0

/ ndf c 195.4 / 175Prob 0.1392p0 2.18± 54.96 p1 0.78± 24.29 p2 0.98± 11.59 p3 1.6± 101.3 p4 0.5± 88 p5 0.42± 26.96

H6568 ADC Kanal 7



/ ndf c 195.4 / 175Prob 0.1392p0 2.18± 54.96 p1 0.78± 24.29 p2 0.98± 11.59 p3 1.6± 101.3 p4 0.5± 88 p5 0.42± 26.96

20 40 60 80 100 120 140 160 180 2000

20

40

60

80

100

120

140

160


/ ndf c 195.4 / 175Prob 0.1392p0 2.18± 54.96 p1 0.78± 24.29 p2 0.98± 11.59 p3 1.6± 101.3 p4 0.5± 88 p5 0.42± 26.96


/ ndf c 195.4 / 175Prob 0.1392p0 2.18± 54.96 p1 0.78± 24.29 p2 0.98± 11.59 p3 1.6± 101.3 p4 0.5± 88 p5 0.42± 26.96


20 40 60 80 100 120 140 160 180 200 2200

10

20

30

40

50

60

70

80


/ ndf c 192.3 / 170Prob 0.1154p0 1.76± 35.03 p1 2.03± 23.82 p2 1.91± 16.62 p3 1.18± 55.75 p4 1.10± 88.31 p5 0.82± 30.52

H6568 ADC Kanal 8



/ ndf c 192.3 / 170Prob 0.1154p0 1.76± 35.03 p1 2.03± 23.82 p2 1.91± 16.62 p3 1.18± 55.75 p4 1.10± 88.31 p5 0.82± 30.52

20 40 60 80 100 120 140 160 180 200 2200

10

20

30

40

50

60

70

80


/ ndf c 192.3 / 170Prob 0.1154p0 1.76± 35.03 p1 2.03± 23.82 p2 1.91± 16.62 p3 1.18± 55.75 p4 1.10± 88.31 p5 0.82± 30.52


/ ndf c 192.3 / 170Prob 0.1154p0 1.76± 35.03 p1 2.03± 23.82 p2 1.91± 16.62 p3 1.18± 55.75 p4 1.10± 88.31 p5 0.82± 30.52


20 40 60 80 100 120 140 160 180 2000

20

40

60

80

100


/ ndf c 163.2 / 153Prob 0.2716p0 1.24± 34.33 p1 7.88± 24.14 p2 3.37± 52.52 p3 1.98± 56.67 p4 0.66± 95.59 p5 0.62± 17.45

H6568 ADC Kanal 9



/ ndf c 163.2 / 153Prob 0.2716p0 1.24± 34.33 p1 7.88± 24.14 p2 3.37± 52.52 p3 1.98± 56.67 p4 0.66± 95.59 p5 0.62± 17.45

20 40 60 80 100 120 140 160 180 2000

20

40

60

80

100


/ ndf c 163.2 / 153Prob 0.2716p0 1.24± 34.33 p1 7.88± 24.14 p2 3.37± 52.52 p3 1.98± 56.67 p4 0.66± 95.59 p5 0.62± 17.45


/ ndf c 163.2 / 153Prob 0.2716p0 1.24± 34.33 p1 7.88± 24.14 p2 3.37± 52.52 p3 1.98± 56.67 p4 0.66± 95.59 p5 0.62± 17.45


20 40 60 80 100 120 140 160 180 2000

20

40

60

80

100


/ ndf c 161.4 / 160Prob 0.4551p0 1.96± 38.54 p1 5.24± 18.54 p2 6.85± 24.61 p3 1.85± 84.23 p4 1.26± 92.37 p5 0.70± 23.04

H6568 ADC Kanal 10



/ ndf c 161.4 / 160Prob 0.4551p0 1.96± 38.54 p1 5.24± 18.54 p2 6.85± 24.61 p3 1.85± 84.23 p4 1.26± 92.37 p5 0.70± 23.04

20 40 60 80 100 120 140 160 180 2000

20

40

60

80

100


/ ndf c 161.4 / 160Prob 0.4551p0 1.96± 38.54 p1 5.24± 18.54 p2 6.85± 24.61 p3 1.85± 84.23 p4 1.26± 92.37 p5 0.70± 23.04


/ ndf c 161.4 / 160Prob 0.4551p0 1.96± 38.54 p1 5.24± 18.54 p2 6.85± 24.61 p3 1.85± 84.23 p4 1.26± 92.37 p5 0.70± 23.04


20 40 60 80 100 120 140 160 180 2000

20

40

60

80

100


/ ndf c 187.4 / 172Prob 0.2001p0 1.63± 39.08 p1 1.12± 28.81 p2 2.05± 17.68 p3 1.6± 87.1 p4 0.66± 99.28 p5 0.49± 23.18

H6568 ADC Kanal 11



/ ndf c 187.4 / 172Prob 0.2001p0 1.63± 39.08 p1 1.12± 28.81 p2 2.05± 17.68 p3 1.6± 87.1 p4 0.66± 99.28 p5 0.49± 23.18

20 40 60 80 100 120 140 160 180 2000

20

40

60

80

100


/ ndf c 187.4 / 172Prob 0.2001p0 1.63± 39.08 p1 1.12± 28.81 p2 2.05± 17.68 p3 1.6± 87.1 p4 0.66± 99.28 p5 0.49± 23.18


/ ndf c 187.4 / 172Prob 0.2001p0 1.63± 39.08 p1 1.12± 28.81 p2 2.05± 17.68 p3 1.6± 87.1 p4 0.66± 99.28 p5 0.49± 23.18


20 40 60 80 100 120 140 160 180 200 2200

20

40

60

80

100

120


/ ndf c 189.5 / 185Prob 0.3948p0 1.3± 33.6 p1 2.81± 24.35 p2 3.75± 23.12 p3 1.48± 85.67 p4 0.8± 105.6 p5 0.57± 26.82

H6568 ADC Kanal 12



/ ndf c 189.5 / 185Prob 0.3948p0 1.3± 33.6 p1 2.81± 24.35 p2 3.75± 23.12 p3 1.48± 85.67 p4 0.8± 105.6 p5 0.57± 26.82

20 40 60 80 100 120 140 160 180 200 2200

20

40

60

80

100

120


/ ndf c 189.5 / 185Prob 0.3948p0 1.3± 33.6 p1 2.81± 24.35 p2 3.75± 23.12 p3 1.48± 85.67 p4 0.8± 105.6 p5 0.57± 26.82


/ ndf c 189.5 / 185Prob 0.3948p0 1.3± 33.6 p1 2.81± 24.35 p2 3.75± 23.12 p3 1.48± 85.67 p4 0.8± 105.6 p5 0.57± 26.82


20 40 60 80 100 120 140 160 1800

20

40

60

80

100

120

140

160


/ ndf c 198.9 / 158Prob 0.01528p0 5.26± 47.15 p1 14.29± -1.14 p2 5.42± 58.33 p3 2.3± 106.4 p4 0.46± 95.29 p5 0.38± 17.94

H6568 ADC Kanal 13



/ ndf c 198.9 / 158Prob 0.01528p0 5.26± 47.15 p1 14.29± -1.14 p2 5.42± 58.33 p3 2.3± 106.4 p4 0.46± 95.29 p5 0.38± 17.94

20 40 60 80 100 120 140 160 1800

20

40

60

80

100

120

140

160


/ ndf c 198.9 / 158Prob 0.01528p0 5.26± 47.15 p1 14.29± -1.14 p2 5.42± 58.33 p3 2.3± 106.4 p4 0.46± 95.29 p5 0.38± 17.94


/ ndf c 198.9 / 158Prob 0.01528p0 5.26± 47.15 p1 14.29± -1.14 p2 5.42± 58.33 p3 2.3± 106.4 p4 0.46± 95.29 p5 0.38± 17.94


20 40 60 80 100 120 140 160 180 200 220 2400

20

40

60

80

100

120H6568 ADC Kanal 14 adc14

Entries 250000Mean 95.57RMS 40.36Underf low 14Overflow 0

/ ndf c 208.1 / 200Prob 0.3325p0 1.6± 40.9 p1 1.1± 27.5 p2 1.62± 16.05 p3 1.38± 83.03 p4 0.6± 107.4 p5 0.51± 30.48

H6568 ADC Kanal 14



/ ndf c 208.1 / 200Prob 0.3325p0 1.6± 40.9 p1 1.1± 27.5 p2 1.62± 16.05 p3 1.38± 83.03 p4 0.6± 107.4 p5 0.51± 30.48

20 40 60 80 100 120 140 160 180 200 220 2400

20

40

60

80

100

120


/ ndf c 208.1 / 200Prob 0.3325p0 1.6± 40.9 p1 1.1± 27.5 p2 1.62± 16.05 p3 1.38± 83.03 p4 0.6± 107.4 p5 0.51± 30.48


/ ndf c 208.1 / 200Prob 0.3325p0 1.6± 40.9 p1 1.1± 27.5 p2 1.62± 16.05 p3 1.38± 83.03 p4 0.6± 107.4 p5 0.51± 30.48


20 40 60 80 100 120 140 160 180 200 2200

20

40

60

80

100

120


/ ndf c 207.6 / 187Prob 0.1435p0 1.54± 38.45 p1 1.05± 31.87 p2 2.09± 18.53 p3 1.60± 92.74 p4 0.7± 103 p5 0.51± 24.89

H6568 ADC Kanal 15



/ ndf c 207.6 / 187Prob 0.1435p0 1.54± 38.45 p1 1.05± 31.87 p2 2.09± 18.53 p3 1.60± 92.74 p4 0.7± 103 p5 0.51± 24.89

20 40 60 80 100 120 140 160 180 200 2200

20

40

60

80

100

120


/ ndf c 207.6 / 187Prob 0.1435p0 1.54± 38.45 p1 1.05± 31.87 p2 2.09± 18.53 p3 1.60± 92.74 p4 0.7± 103 p5 0.51± 24.89


/ ndf c 207.6 / 187Prob 0.1435p0 1.54± 38.45 p1 1.05± 31.87 p2 2.09± 18.53 p3 1.60± 92.74 p4 0.7± 103 p5 0.51± 24.89


h6568_led360nm_950V.asc ii

Individual ADCIndividual ADCspectra for eachspectra for eachchannelchannel

gain vs HV for eachgain vs HV for eacheach MAPMT anodeeach MAPMT anode



MAPMT GAIN AT HIGH RATEMAPMT GAIN AT HIGH RATEmean signal amplitude versus rate/pixelmean signal amplitude versus rate/pixelpulsed light source pulsed light source synchronussynchronus to trigger + random background from lampto trigger + random background from lamp

measured for single photoelectronmeasured for single photoelectron

Working HV Working HV

Goal Goal (for the future (for the future needs of COMPASS):needs of COMPASS):operate up tooperate up to5MHz/pixel5MHz/pixel single single photoelectron ratesphotoelectron rates

no rate limitation from no rate limitation from MAPMTMAPMT



SINGLE PHOTOELECTRON DETECTIONSINGLE PHOTOELECTRON DETECTION

a flat region (no photon loss), a flat region (no photon loss), good for safe threshold settinggood for safe threshold setting, is clearly identified , is clearly identified betweenbetween the the crosscross--talk regiontalk region and the and the region where detection loss startsregion where detection loss starts (third plot)(third plot)

Plots: Plots: hits /event hits /event vsvs threshold threshold

settingsetting

~ 90 fC~ 30 fC ~ 270 fC

cross-talk

plateauplateau

0 100 200 300 400 500 600

hEntries 250000

Mean 76.53

RMS 58.02

Underflow 0

Overflow 0

0 100 200 300 400 500 600

200

400

600

800

1000

1200

1400

freeEntries 250000

Mean 76.53

RMS 58.02

Underflow 0

Overflow 0

pedestal1 multiplication stage less

1 e

2 eall these photoelectrons all these photoelectrons must be detected for must be detected for good efficiency good efficiency

Single photoelectron : Single photoelectron : wide dynamic rangewide dynamic range

efficiency:efficiency:~ 95%~ 95%



SCHEDULE OF ASSEMBLINGSCHEDULE OF ASSEMBLINGPreliminary studies up to Preliminary studies up to October 2004October 2004Project design Project design November 2004 November 2004 –– March 2005March 2005Material procurement and constructions Material procurement and constructions April 2005 April 2005 -- March 2006March 2006Assembly Assembly AprilApril--May 2006May 2006Ready for beamReady for beam , , June 2006June 2006



The Upper Detector from insideThe Upper Detector from inside



The central part of the lower detector



Performances of RICH APV electronics

Amplitude spectrum for clusters associated with tracks

the average collected charge is ~9000 e- @ 2000V(noise level: ~680 e-)

time resolution (ns)versus amplitude:

almost dead-time free



ON LINE EVENT DISPLAY FOR THE CENTRAL AREA

10 ns time window



RINGSRINGS



photon time peakphoton time peak

M M (GeV/c(GeV/c22))



time resolution is useful for correctly assigning hits to rings



Number of detected photonsNumber of detected photons

Nph

Nph

θCh(mrad) θCh(mrad)

θCh(mrad) θCh(mrad)

in the four quarters of the central areain the four quarters of the central area

mean background counts per ring ~ 8mean background counts per ring ~ 8



theta(mrad) vs p (GeV/c) - pion, kaon

0

10

20

30

40

50

60

0 10 20 30 40 50 60 70

p (GeV/c)

thet

a (m

rad)

UPGRADED RICH PERFORMANCESUPGRADED RICH PERFORMANCES

NNphph / ring/ ring ~ 60 ~ 60 ((ββ ≈≈ 1) IN THE CENTRAL REGION1) IN THE CENTRAL REGION

σσringring ~ 0.3 ~ 0.3 mradmrad ((ββ ≈≈ 1) 1) (2004: (2004: σσringring = 0.6 = 0.6 mradmrad))

2 2 σσ ππ/K separation up to p > 55 /K separation up to p > 55 GeV/cGeV/c (2004:(2004: 2 2 σσ ππ/K p=43 /K p=43 GeV/cGeV/c))

effective Cherenkov threshold: effective Cherenkov threshold: see plotsee plot

Time resolution < 1 nsTime resolution < 1 ns

“ring reconstruction”only after the upgrade

PID capability extended with the upgrade

K

π



invariant mass (GeV/cinvariant mass (GeV/c22)) invariant mass (GeV/cinvariant mass (GeV/c22))

preliminary

preliminary2006 2004

Improved efficiencyImproved efficiency

Probability of correclty identify a kaon in the most delicate kiProbability of correclty identify a kaon in the most delicate kinematic regionnematic region isisestimated using kaons from decay of exclusively produced estimated using kaons from decay of exclusively produced φφ(1020) mesons(1020) mesons



preliminary

preliminary

invariant mass (GeV/cinvariant mass (GeV/c22)) invariant mass (GeV/cinvariant mass (GeV/c22))

2006

2004

Improved purityImproved purity

Probability of misidentification of a true pion as a kaon in theProbability of misidentification of a true pion as a kaon in the most delicatemost delicatekinematic regionkinematic region isis estimated using pions from decay of exclusively produced Kestimated using pions from decay of exclusively produced Kss



Improved PID performancesImproved PID performances

M M (GeV/c(GeV/c22))

2004 data2004 data

2006 data2006 data



ConclusionsConclusions

COMPASS RICHCOMPASS RICH--1 has undergone a major upgrade,1 has undergone a major upgrade,changing changing r/or/o electronics for electronics for CsICsI MWPC and implementing aMWPC and implementing a

fast photon detection system based on fast photon detection system based on MAPMTsMAPMTs in the central area.in the central area.

The design and construction took 1.5 y:The design and construction took 1.5 y: November 2004 November 2004 –– May 2006May 2006

During the COMPASS run in 2006 the upgraded RICHDuring the COMPASS run in 2006 the upgraded RICH--1 showed:1 showed:~60 detected photons, N~60 detected photons, N00 ~ 70, ~ 70, σσθθCC

~ 0.3 ~ 0.3 mradmrad, , σσtt < 1 ns.< 1 ns.

It can stand ~ 100 kHz trigger rate, it has high efficiencyIt can stand ~ 100 kHz trigger rate, it has high efficiencyand purity and 2and purity and 2σσ ππ--K separation at > 55 K separation at > 55 GeV/cGeV/c

COMPASS RICHCOMPASS RICH--1 has really outstanding performances1 has really outstanding performances



… that made this project a reality so effectively and so quickly

P.Abbon(11), M.Alekseev(12), H.Angerer(9), M. Apollonio(13), R.Birsa(13), P.Bordalo(7), F.Bradamante(13), A.Bressan(13), L.Busso(12), M.Chiosso(12), P.Ciliberti(13), M.L.Colantoni(1), S.Costa(12), T.Dafni(11), S.Dalla Torre(13), E.Delagnes(11), H.Deschamps(11), V.Diaz(13), N.Dibiase(12), V.Duic(13), W.Eyrich(4), D.Faso(12), A.Ferrero(12), M.Finger(10), M.Finger Jr(10), H.Fischer(5), S.Gerassimov(9), M.Giorgi(13), B.Gobbo(13), D.von Harrach(8), F.H.Heinsius(5), R. Joosten(2), B.Ketzer(9), V.N. Kolosov(3)*, K.Königsmann(5), I.Konorov(9), D.Kramer(6), F.Kunne(11), A.Lehmann(4), S. Levorato(13), A.Maggiora(12), A.Magnon(11), A.Mann(9), A.Martin(13), G.Menon(13), A.Mutter(5), O. Nähle(2), F.Nerling(5), D.Neyret(11), P.Pagano(13), S.Panebianco(11), D.Panzieri(1), S.Paul(9), G.Pesaro(13),C. Pizzolotto(4), J. Polak(6), P.Rebourgeard(11), E. Rocco(13), F.Robinet(11), P.Schiavon(13), C.Schill(5), P.Schoenmeier(4), W.Schröder(4), L.Silva(7), M.Slunecka(10), F.Sozzi(13), L.Steiger(10), M.Sulc(6), M.Svec(6), F.Tessarotto(13), A.Teufel(4), H. Wollny(5)

(1) INFN, Sezione di Torino and Universita’ del East Piemonte, Alessandria, Italy(2) Universität Bonn, Helmholtz-Institut für Strahlen- und Kernphysik, Bonn, Germany(3) CERN, European Organization for Nuclear Research, Geneva, Switzerland (4) Universität Erlangen–Nürnberg, Physikalisches Institut, Erlangen, Germany(5) Universität Freiburg, Physikalisches Institut, Freiburg, Germany(6) Technical University of Liberec, Liberec, Czech Republic(7) LIP, Lisbon, Portugal(8) Universität Mainz, Institut für Kernphysik, Mainz, Germany(9) Technische Universität München, Physik Department, Garching, Germany(10) Charles University, Praga, Czech Republic and JINR, Dubna, Russia(11) CEA Saclay, DSM/DAPNIA, Gif-sur-Yvette, France(12) INFN, Sezione di Torino and Universita’ di Torino, Torino, Italy(13) INFN, Sezione di Trieste and Universita’ di Trieste, Trieste, Italy

THE TEAMTHE TEAM

Alessandria BonnCERN (Geneve) ErlangenFreiburg TUM (Munich)Liberec LIP (Lisbon)Mainz PragueSaclay TorinoTrieste

the fast photon detection system of compass rich-1 · vienna, 23/02/2007 - the 11th vienna...

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