Mike AlbrowAll Experimenters, June 8 th 2009T979: Tests of Precision Timing Detectors @ MTest 1 Tests of Fast Timing Detectors in the Meson Test Beam (T979)

1Mike Albrow All Experimenters, June 8th 2009T979: Tests of Precision Timing Detectors @ MTest

Tests of Fast Timing Detectors in the Meson Test Beam(T979) MTest : May 27th – June 2nd

Mike Albrow, Sasha Pronko, Erik Ramberg, Anatoly Ronzhin, Andriy Zatserklyaniy+ detector simulations by Hans Wenzel & Earle Wilson (student)

Motivations for ~ ps / 10 ps timing detectors

Set-up and triggers etc.

Detector configurations:

A) A – B – C in lineB) A+B transverse bars – CC) Q-bar1(A) – Q-bar2(B) – CD) Aerogel(C) – BE) Si-PMTsF) Photonis1 – Photonis2 – C in lineG) Q-bar1(A) – Q-bar2(B) – 8.7 m flight path --- C in line

Thoughts about next steps

To be explained!

Only if you ask!


Motivations:Timing on single particles σ(t) typically >~ 100 psA factor 10 – 100 improvement likely to have unforeseen benefits.We know of some (foreseen), e.g.:

Particle ID in beamsE.g. at 25 GeV/c, over 15m:Δt(π-K) = 20 psΔt(K-p) = 50 psor at 10 GeV/c, over 30m:Δt(π-e) = 10 ps==================Areas ~few cm2, want thin.

Particle ID in large detectors(~CDF-like or ILC)E.g. at 6 GeV/c, over 1.5m:Δt(π-K) = 17 psΔt(K-p) = 43 ps==================Areas ~several m2, want thin.

Pile-up reduction e.g. in FP420:Extensions to CMS & ATLAS in prepn.p + p p + H + p + nothing elseMeasure p’s M(H), J, C, P, Γ

CMS

Hp p240m … 420m240m … 420m

Argonne-Chicago-(Henry Frisch et al.)

Fermilab group

3

21

PET-TOF β+e Δt = 10ps : Δ z = 3mm

4


to CMS Exec Board Summer 2008(ATLAS is also reviewing)

2.1mm/10psp)Δt(pc2

1TOF)Δz(pp,

?z(vertex) from pp == z(vertex) central

Pile-up reduction in FP420Want L ~ 10^34, <n> ~ 25/x

cf σ(z)vtx ~ 60 mm


At MTest, 120 GeV/c p, ~40,000/spill

Simple trigger (schematic):2mm x 2mm scint. VETO w/hole2 PMTs in AND 2 PMTs in OR

Calibrate electronics resolution with same pulse start & stop: σ ~ 3 ps Cerenkov light in Quartz window. HV ~ 4.5 kV, G ~ 5.10^5

Dark & shielded box

PHOTEK 2102 MCP, 10mm Φ

PHOTEK 2402 MCP, 40mm Φ

210

First A-B-C in line

MCP-PMT-A

ORTEC566, 567

TAC/SCA

ORTECAD114ADC

ATTENUATOR

ADC

ATTENUATORMCP-PMT-B

DAQ

ADC

CBA

Schematic DAQ :

T1


A-B-C in-line results: Cerenkov light in PMT windowsAll numbers “preliminary”, to be double-checked

ADC distributions: cut out tails and stragglers (~ 10%)T1 = tA – tBT2 = tA – tCT3 = tB – tC=======Check Ti(PH A,B)Make slewing corrections

Unfold:

A

BC

23

22

21

2

1TTTA

etc. PMT-1 (Photek-210, 4.7 kV)=12.0 psPMT-2 (Photek-210, 4.6 kV)=12.0 psPMT-3 (Photek-240, 4.2 kV)=7.7 ps

Cerenkov light in PMT windows


Double Q-barQuartz (fused silica) bars 6mm x 6mm x 90mm PHOTEK 210Mounted at Cherenkov angle θc ~ 48deg. on opposite sides.dz = 6mm/sin(48) = 8.1mm. Some light direct to PMT, ~1/2 TIR to PMTBlack “sock” over bars just to avoid light sharing

C

B

A

Unfold:σ(A) = 22.3 psσ(B) = 30.5 ps

Includes electronics (~3 ps)and 2 mm beam width smear (A,B)Δt = 2 mm x (10 ps/2 mm)

ps 28.71035.30

ps 9.711033.22

222

222

B

A

Combining [AB] removesbeam spread (later, tracking)


σ = 6.04 ch = 18.7 psUnfold C = 7.7 ps, σ(AB) = 17.0 ps

Resolution of double-Qbar

2 mm x-spread not to be subtracted(only 3 ps electronics)

Resolution of Double-Qbar as one device

T3)3T2(T14

1C

2

BA

*

* Derivation in back-up


Switched on, saw signals!

A = Aerogel

B

Corrected T2 = A-B = 10.8 ch = 33.5 ps (before unfolding)


Aerogel results:Unfolding indirect because only 2 PMTs in run.A (Aerogel on 240) and B(210 in beam)T1 = t(A) – t(B) corrected for smearing:10 mm aero σ(T1) = 43.7 ps20 mm aero σ(T1) = 45.3 ps30 mm aero σ(T1) = 33.5 ps Unfold with σ(1) = 12 ps from in-line

σ (Aerogel 30 mm) ~ 31 ps

<P.H.> = 46 ch. (10mm) 72 ch. (30 mm)

Aerogel + mirror ~ massless & short (~ 5 cm), simple.Can have several in line, independent √NBUT: have large 240 tube close to beamPossibilities to focus light : smaller tube farther away, to be simulated

AEROGEL

MCP-PMT


Tests of SiPMs = silicon photomultipliers

Eight Hamamatsu SiPMs, 3mm x 3mmIn beam with quartz Cherenkov radiatorsseveral thicknesses (4 – 12mm), mirrored and not mirrored.

Best conditions σ(t) ~ 33 – 37 ps

10-15 photoelectrons

Channels

Between SiPMs and C. Slewing correction applied


World’s Best Beamline Time-of-Flight System?

24 psec resolution positron peak,Using average of A & B times

Can measure momentum of a proton with 2 MCP-PMTs! (if you know it’s a proton!)

Start = Double-Q-barStop = Photek 240Start-stop dist. = 8.7 m Predictions of proton positions


Possible Next Steps

For FP420 a σ(t) = 10 ps edgeless detector we learnt a way including CMS-compatible electronics/DAQwith reference time signals (jitter <~ 5 ps)

θc = 48deg Q-bars onto PHOTEK 240 MCP-PMTs

40 mm diam. MCP

6mm x 6mm barsTIR: isolated

p

20mm

I

“beam” only 6mm vert.,20 mm horiz.

MCP

MCP

Should get < 8 ps

+ More aerogel? To test in Fall?


We thank:

PHOTEK Ltd (UK) for loan of MCP-PMTsAccelerator Division Ops for beam, and patience over many accessesJim Pinfold and Don Summers for gift of aerogelCarl Lindenmeyer and John Korienek for Q-bar supportRick Coleman for low energy beamsHogan Ngyuen & SiDet dept. for many things

From FP420 R&D doc.

LHC beam


T1 = A - BT2 = A - CT3 = B - C ------------T1 + T2 = A - B + A - C3 x T3 = 3B - 3Cso T1 + T2 + 3x T3 = A - B + A - C + 3B - 3C = 2A + 2B - 4Cand 1/4 ( T1 + T2 + 3x T3 ) = (A+B)/2 - C

Back Up

T3)3T2(T14

1C

2

BA

Why:

Mike AlbrowAll Experimenters, June 8 th 2009T979: Tests of Precision Timing Detectors @ MTest 1 Tests of Fast Timing Detectors in the Meson Test Beam (T979)

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