RICH 2007 highlights Antonis Papanestis RAL. Study of a Silica Aerogel for a Cherenkov Radiator Ichiro Adachi KEK representing for the Belle Aerogel RICH

RICH 2007 highlights

Antonis PapanestisRAL

Study of a Silica Aerogel for a Cherenkov Radiator

Ichiro Adachi

KEKrepresenting for the Belle Aerogel RICH R&D group

2007 October 15-20

RICH2007, Trieste, Italy

Silica Aerogel Production

• Production Method Sol-gel process

nSi(OR)4 + 4nH2O nSi(OH)4 + 4nH2O hydrolysisnSi(OH)4 (SiO2)n + 2nH2O condensation

Chemical treatment to make hydrophobic Supercritical drying

CO2 extraction method 31 degree Celsius and 7.5 MPa

• Optical Quality Transparency

T = T0*exp(-d/) where T is light intensity and d sample thickness Refractive index measured with Fraunhofer method These properties are strongly related to:

Chemical solvent Mixing ratio between them

3 dimensional network

History of Aerogel Production

20

50

tran

smis

sion

leng

th a

t 40

0nm

(m

m)

refractive index

1.010 1.040 1.070 1.100

1st generation:1970’s-1980’sTASSO/PETRA1.025 ~ 1.055

2nd generation:1992-2002Belle Aerogel counter/KEKB1.010 ~ 1.030new production methodhydrophobic

3rd generation:2002- A-RICH for Belle upgrade1.030 ~ 1.080new solventI

II

III

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

108 108.5 109 109.5 110 110.5 111 111.5

Angle

Inte

nsi

ty

Index Scan Study (1)

• Relative weight for each composition in an aerogel was examined with XRF (X-ray fluorescence) analysis

• X-ray tomography device was used to scan relative aerogel density difference

X-ray =0.156nm

beam spot < 1mm

element Si O C

weight(%) 43.4% 50.6% 6.0%

Si

Index Scan Study (2)

109mm

109mm

• density relative uniformity

Distance from edge(mm)

Den

sity

rat

io(%

)

edge

center

middle

(n-1)/(n-1) ~ +/-0.02

Index (Fraunhofer method at 405nm) = 1.0577 +/- 0.0006

10.7mmt

need further studies

preliminary value:

Block Size

• Large sample produced Can be used for real detector 150 x 150 mm2 cross section Thickness: 10 mm and 20 mm

0% 50% 100%

1.045

1.050

1.055

1.060

150x150x20

150x150x10

100x100x10

“crack-free” rate by visual scan

110x110x20mm3 150x150x20mm3

n =1.050

Machining Possibility

• Hydrophobic feature allows us to use “water-jet” cutter for machining

highly pressurized water injected via very small hole to a sample

hexagonal shape for two samples

110mm150mm

Multiple-Layer Sample

two-layer sample with 160x160x20 mm3 has been successfully producedone can use two aerogel layers as one unit

n = 1.045

n = 1.050

160mm

transmission length(400nm): 46mm

old new

stress inside a tile well controlled

Focusing Aerogel RICH Optimization

A.Yu.Barnyakov, M.Yu.Barnyakov, V.S.Bobrovnikov, A.R.Buzykaev, V.V.Gulevich, S.A.Kononov, E.A.Kravchenko, A.P.Onuchin

Budker Institute of Nuclear Physics, Novosibirsk, RussiaA.F.Danilyuk, V.L.Kirillov

Boreskov Institute of Catalysis, Novosibirsk, Russia

Presented by E.A.Kravchenko

Sodium fluoride radiatorSodium fluoride radiatorSuggested for RICH with a TEA/TMAE pad-photon detector byR. Arnold et al. [ NIM A273 (1988) 466 ]

• Good transparency in visible & near UV,• Almost no light scattering as compared with aerogel,• More firm and stable material, though toxic.

√2

NaF has the lowest refractive index among solids (except aerogel).

2n for λ >170 nm

Multilayer aerogelMultilayer aerogel

100x100x41 mm, Lsc = 45 mm at 400 nm

Xray measurement, density distributionXray measurement, density distribution

The increase in density at the internal borders is the result of the production procedure (diffusion).

Does it effect the performance?

Layer <n> n, (optimal)

n, (design)

h, mm

h, mm (design)

1 1.046 1.046 1.050 12.6 12.5

2 1.041 1.040 1.044 13.2 13.3

3 1.037 1.035 1.039 15.2 14.2

Monte Carlo simulation of longitudinal refractive index fluctuations

Monte Carlo simulation of longitudinal refractive index fluctuations

200 mm expansion gap

3 types of radiators 3layer as designed (ideal) Xray data avereged to 3 layers Xray data avereged to 14 layers

Simulation results, π/K separationSimulation results, π/K separation

Npe =14 σβ = 5∙10-4

‘optimal’ radiator → best resolution for 4 GeV/c pions ‘real’ experimental radiator → best resolution for 3.5 GeV/c kaons

π/K separation up to 8 GeV/c (>3σ)

Status of aerogel productionStatus of aerogel production ~2000 liters have been

produced for KEDR ASHIPH detector, n=1.05

14 blocks 20020050 mm have been produced for LHCb RICH, n=1.03

~200 blocks 11511525 mm have been produced for AMS RICH, n=1.05

n=1.13 aerogel for SND ASHIPH detector

n=1.008 aerogel for the DIRAC

3-4 layers focusing aerogel

High optical parameters (Lsc≥43mm at 400 nm)Precise dimensions (<0.2 mm)

KEKDTP

RICH2007 @Trieste Junji Haba, KEK

Status and perspectives of

solid state photon detectors for single photon detection Pixelated Photon Detector (PPD)

Junji Haba, KEK


顕微鏡写真

受光面に関して、 3mm と 1mmとはほぼ同じに見えている

H- １ｍｍ H- ３ｍｍ

3. TestInstallation of 4 MPPC in frontOf the MAGIC cameraTrigger by air shower C-lightComparison of signal in neighborPmt cells (9 cm**2)With 4 g-apd pixels (0.36 cm**2)Readout by 2 Ghz F-ADC

E. Lorentz @PD07For MAGIC collaboration


Future improvements expected

Larger PDE Wider Area Lower Noise Less crosstalk Wider dynamic range (and really cheaper price)


Larger PDE

Higher fill factor is a key MRS(Metal Resitive Semiconductor)

APD (CPTA) Backside illumination &Drift (MPI)


Wider area devices

1.3mm to 3 mm device test in progress at several places. Higher noise though, as

expected. Light collection. Drift type device

(MPI)

H.G. Moser @PD7

S. Korpar@this WS


Less noise

Thinner epi layer (compromise long sensitivity though)

Less defects. Epi quality or gettering technology.


Less crosstalks

Separation trenches can help to reduce crosstalk rate.There may be a side effect.

Yamamoto@PD07

C. Piemonte@FNAL seminar

Production and Tests of Hybrid Production and Tests of Hybrid Photon Detectors for the LHCb Photon Detectors for the LHCb RICH DetectorsRICH Detectors

Introduction Hybrid Photon Detectors Production Test results Conclusions

RICH 2007, Trieste, 17.10.2007RICH 2007, Trieste, 17.10.2007

Stephan Eisenhardt, University of EdinburghStephan Eisenhardt, University of EdinburghOn behalf of the LHCb experimentOn behalf of the LHCb experiment

RICH2RICH1

LHCb

HPD

RICH 2007, Trieste, 17.10.2007 Stephan Eisenhardt 26

PDTF – TestsPDTF – Tests Comprehensive test of every function and parameter of the HPD:

Readout ChipConnectionsCommunicationsDAC linearityReadout modesDead ChannelsNoisy ChannelsPixel maskingThresholdNoise

PhotocathodeDark CountResponse to lightQuantum Efficiency

HPD BodyDimensionsQuartz windowPin Grid ArraySensor position

Electron Optics /Tube VolumeImagingDemagnificationHV StabilityField DistortionsIon Feed BackVacuum Quality

Silicon SensorIV CurveDepletionBump-BondingEfficiency (Backpulse)


Testing Programme – SummaryTesting Programme – Summary

result:pass: 547 ~98%fail: 12 ~ 2%


Quantum Efficiency – DEP DataQuantum Efficiency – DEP Data Excellent sensitivity:

– increase due to process tuning at DEP

– single most helpful improvement to RICH performance

– <QE @ 270nm> = 30.8%

>> typical QE = 23.3%

<QE> @ 270 nm (per batch)

19

21

23

25

27

29

31

33

35

37

0 2 4 6 8 10 12 14 16 18 20 22 24batch no.

aver

age

QE

[%

] .

<QE> per batch

running <QE> (batch 0-25)

more tuning improvements:– fill of sensitivity dip between UV and

visible

– reduction of red sensitivity @ 800nm• anti-correlated to blue sensitivity• cause of thermal e--emission (dark count)

QE

[%

]

Wavelength [nm]

RMS ofbatch spread

<QE> per delivery batch

QE

[%

]

Batch number

<QE> (DEP Data): across delivery batches


QE – LHCb VerificationQE – LHCb Verification PDTF measurement:

– 7 wavelengths, 10nm bandpass filter

– error: 2%

– 76 HPD measured

PDTF QE measurements typically

matches DEP values within 3%

QE PDTF vs DEP

-0.050

0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.000 0.050 0.100 0.150 0.200 0.250 0.300 0.350 0.400

DEP QE, hq (no units)

PD

TF Q

E, h q

(no u

nits

)

.

270

340

400

440

520

640

800

y=x

PDTF measurements confirm

shape of spectra & absolute values full trust in DEP measurements

Quantum Efficiency - typical HPD sample

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0 100 200 300 400 500 600 700 800 900 1000

Wavelength / nm

QE

, hq , (n

o u

nits

)

.

H648005: DEP

H648005: PDTF

H612011: DEP

H612011: PDTF

H650003: DEP

H650003: PDTF

H545002: DEP

H545002: PDTF

4 tests across QE range

Q

E

wavelength [nm]

all tests: PDTF vs. DEP

Q

E –

PD

TF

QE – DEP

Commissioning of the LHCb RICH Detector

C. D’Ambrosio(CERN, Geneva, Switzerland)

on behalf of the LHCb – RICH CollaborationOutline

LHCb and its RICHes

What is Commissioning and Commissioning Strategy

RICH Commissioning, a (hi)Story

First Results

Conclusions and Outlook

•Regular Meetings (everyday coffees and weekly phone-conferences)

•Hard and soft interlocks enabled from the beginning

•Monitoring systems

•Vessel, HPD boxes, electronics and electrics temperature, pressure and humidity sensors

•Voltages and currents

•Distributed and smart alerts, alarms, feedbacks and reactions

•No development at the pit (at least we tried as much as we could…)

(see Mario)

Safety (…and more)

…or the so called “one click startup”… (well, two clicks at the moment!)

RICH Starting ProcedureRICH2 ECS panel

DCS

DAQ (L0 & L1)

HPD boxconditions

RICH2 Overview

High Voltage was ramped very slowly and with the full system on, in order to monitor in real time the HPDs behaviour.

FIAT LUX (first photons detected)

A red light emitting monomode fibre injects a controlled quantity of photons in the vesselNumber of photoelectrons

Excellent!

This is the distribution of the total number of phel per event (~2.4 Millions active channels).

Social programme

Ratio social activities/talks ~ about right (50:50)

Documents

RICH 2007 highlights Antonis Papanestis RAL. Study of a Silica Aerogel for a Cherenkov Radiator Ichiro Adachi KEK representing for the Belle Aerogel RICH