QUARTIC- A Precise ToF Detector for the FP420 Project James Pinfold For the QUARTIC Working Group...

QUARTIC- A Precise ToF QUARTIC- A Precise ToF Detector for the FP420 ProjectDetector for the FP420 Project

James PinfoldJames PinfoldFor the QUARTIC Working For the QUARTIC Working

GroupGroup

René Magritte: Empire of Light

http://www.users.cloud9.net/~bradmcc/GO/EmpireOfLight.jpg

The QUARTIC Working GroupThe QUARTIC Working Group

• University of Alberta: University of Alberta: Lars Holm, Lars Holm, James PinfoldJames Pinfold, , Drew Price, Jan Schaapman, Yushu YaoDrew Price, Jan Schaapman, Yushu Yao

• Fermilab:Fermilab: Mike Albrow Mike Albrow

• University of Texas at Arlington:University of Texas at Arlington: Andrew BrandtAndrew Brandt, , Chance Harenza, Joaquin Noyola, Pedro DuarteChance Harenza, Joaquin Noyola, Pedro Duarte

Associated GroupAssociated Group

• University of Louvain:University of Louvain: Krzysztof Piotrzkowski Krzysztof Piotrzkowski

James Pinfold Manchester Meeting December 2005James Pinfold Manchester Meeting December 2005

Initial Conception of QuarticInitial Conception of Quartic

• AIM: Use a precise ToF Cerenkov detector to match z(vertex) with AIM: Use a precise ToF Cerenkov detector to match z(vertex) with central track vertex and thus reduce backgrounds to, for example, central track vertex and thus reduce backgrounds to, for example, exclusive diffractive Higgs productionexclusive diffractive Higgs production

• Z of interaction = c(TR-TL)/2 where TR(TL) is the time measured in Z of interaction = c(TR-TL)/2 where TR(TL) is the time measured in the RHS(LHS) QUARTIC detectors (420m from IP) -the RHS(LHS) QUARTIC detectors (420m from IP) -

• We havez (mm) =0.21 t (psec) (2.1 mm for t=10 ps [ct/√2])

TL TR

TL

TR

z_vtx

z

t

X

We are aiming for We are aiming for ~10ps resolution ~10ps resolution (3mm at the speed (3mm at the speed of light)of light)


Where do the Protons Go?Where do the Protons Go?

y120 GeV120 GeVHiggsHiggs

x

3mm3mm

SDSDBackgroundBackground

X- cms X- m

120 GeV120 GeVHiggsHiggs

3mm

(420m+420m)(420m+420m)ALLALL


Initial Geometry for QUARTIC*Initial Geometry for QUARTIC*

MCP-PMTMCP-PMT

proton

oCerenk Cerenk

oi i

For quartz n(λ)~1.54

1 1cos(θ )= = = 0.65; θ =49.5

βn n

1For TIR sin(θ ) = = 0.65; θ = 40.5

n

Cerenkov Photons


20 fused silica bars 6mm20 fused silica bars 6mm22 x 100 mm x 100 mm NB fused silica is rad-hard NB fused silica is rad-hard

* From Mike Albrow

Achieved – a 10ps Timing Resolution Achieved – a 10ps Timing Resolution

The problem is we cannot put a PMT in a 7 TeV beam.


What is aWhat is a MCP-PMT?MCP-PMT?

Burle 2” MCP-PMT

The MCP-PMT is a micro channel plate equipped with a The MCP-PMT is a micro channel plate equipped with a photocathode & (usually) a multi-anode readoutphotocathode & (usually) a multi-anode readout


Geant4 SimulationGeant4 Simulation

• The detector simulation includes:The detector simulation includes:–Tracking and timing of Cerenkov photons to the MCP-PMT Tracking and timing of Cerenkov photons to the MCP-PMT

–Wavelength dependent refractive index, attenuation & reflectivity Wavelength dependent refractive index, attenuation & reflectivity

–Ability to study cladding (eg air) or a reflective layer (with a Ability to study cladding (eg air) or a reflective layer (with a possibility of including diffuse reflection)possibility of including diffuse reflection)

–The effects of coupling grease (if necessary)The effects of coupling grease (if necessary)

Al reflection (Cladding with NA=0.37)


Simulating the MCP-PMTSimulating the MCP-PMT

• Arrival time at the face of the MCP-PMT recordedArrival time at the face of the MCP-PMT recorded

• Simulate geometrical acceptance Simulate geometrical acceptance

• Implement wavelength dependence of the photo-cathode QE.Implement wavelength dependence of the photo-cathode QE.

• Simulate PMT transit-time jitter by adding a normally distributed Simulate PMT transit-time jitter by adding a normally distributed random time jitter with the appropriate standard deviationrandom time jitter with the appropriate standard deviation

• Simulate the layout of the anode pad readout of the MCP-PMT.Simulate the layout of the anode pad readout of the MCP-PMT.

• Assume that when the MCP-PMT o/p voltage reaches a certain Assume that when the MCP-PMT o/p voltage reaches a certain level it triggers the discriminator – this level corresponds to a level it triggers the discriminator – this level corresponds to a certain number of photons having arrived.certain number of photons having arrived.


Cerenkov Light in Fused Silica*Cerenkov Light in Fused Silica*

*UTA simulation

λ #PH QE #PH*Q E Θc n

180-250 1652.6 15.70% 259.5 49.6 1.544

250-350 1148.7 18.00% 206.8 47.8 1.490

350-450 624.7 19.90% 124.3 47.2 1.471

450-550 394.3 11% 43.4 46.9 1.464

550-650 271.1 1.50% 4.1 46.7 1.458

total 4100 638.0

22 2

1

# . 2 sin( ) 1/ ph L c d

UV is important! 640 total pe’s : ~130 pe’s/6mm rod (collection efficiency reduces this number to ~80 pe’s/bar)


Photon Arrival Times (1)Photon Arrival Times (1)

red = totally internally reflected lightgreen = extra light if aluminized

PicosecondsPicoseconds

QE not included

First 10ps 22 photonsFirst 10ps 22 photonsFirst 20ps 51 photonsFirst 20ps 51 photonsFirst 30ps 80 photonsFirst 30ps 80 photonsFirst 40 ps 107 photonsFirst 40 ps 107 photons

Half maximum rise time ~3psHalf maximum rise time ~3ps

Nu

mb

er o

f p

ho

ton

s


(From Ray Tracing)

Photon Arrival Times (2)Photon Arrival Times (2)

red = totally internally reflected lightgreen = extra light if aluminized

QE included

First 10ps 3 pe’sFirst 10ps 3 pe’sFirst 20ps 8 pe’sFirst 20ps 8 pe’sFirst 30ps 12 pe’sFirst 30ps 12 pe’sFirst 40ps 16 pe’sFirst 40ps 16 pe’s

Half maximum rise time ~3psHalf maximum rise time ~3ps

PicosecondsPicoseconds

Nu

mb

er o

f p

ho

toel

ectr

on

sN

um

ber

of

ph

oto

elec

tro

ns


(From Ray Tracing)

QUARTIC Background Rejection (1)QUARTIC Background Rejection (1)

A.A. 2 single diffractive 2 single diffractive protons overlapping protons overlapping a hard scatter a hard scatter

B.B. A hard scatter with A hard scatter with an overlapping double an overlapping double pomeron event pomeron event

C.C. A hard single diffractive A hard single diffractive event overlapping a event overlapping a soft diffractive soft diffractive eventevent

Rule of thumb: ~1% of interactions have a proton at 420mRule of thumb: ~1% of interactions have a proton at 420m

97.4% of events have primary (PV) vertex and fake vertex (FV) more than 2.1mm (1) apart.

PV

FV

97.8% of events have primary (PV) vertex and second vertex (SV) more than 2.1mm (1) apart.

95.5% of events have primary (PV) vertex and fake vertex (FV) more than 2.1mm (1) apart.

PV

PV

SV

FV


Background Rejection (2) Background Rejection (2)

A.A. Two single diffractive protons overlapping a hard scatterTwo single diffractive protons overlapping a hard scatterB.B. A hard scatter with an overlapping double pomeron eventA hard scatter with an overlapping double pomeron eventC.C. A hard single diffractive event overlapping a soft diffractive A hard single diffractive event overlapping a soft diffractive

eventevent

Background rejection


Frontend Readout (1Frontend Readout (1stst version) version)

• High precision Alberta CFD Aiming for 20-ps resolution.High precision Alberta CFD Aiming for 20-ps resolution.

• Using CERN HPTDC as key component. Using CERN HPTDC as key component.

– Dead time free.Dead time free.

– 32 channels/chip32 channels/chip 。。 SizeSize ～～ 2.7×2.7 cm2.7×2.7 cm22 。。– External clockExternal clock ：： 40MHz40MHz 。。 Synchronized to bunches.Synchronized to bunches.

• Time resolution (RMS)Time resolution (RMS) ：：– 70ps medium resolution mode 70ps medium resolution mode

– 35ps high resolution mode 35ps high resolution mode

– 15ps very high resolution mode (8ch per chip)15ps very high resolution mode (8ch per chip) 。。• Double pulse resolutionDouble pulse resolution ：： 5ns (typical); 10ns (guaranteed). 5ns (typical); 10ns (guaranteed).

Separate leading or trailing edge measurement; Separate leading or trailing edge measurement;

• Simultaneous measurement of leading edge and pulse width Simultaneous measurement of leading edge and pulse width (not true for very high resolution mode).(not true for very high resolution mode).


Test-beam at FermilabTest-beam at Fermilab

• Planned for summer of 2006 (beam starts in mid-June)Planned for summer of 2006 (beam starts in mid-June)• Test-beam manned by UTA and AlbertaTest-beam manned by UTA and Alberta• Online/DAQ development required for QUARTIC prototype Online/DAQ development required for QUARTIC prototype

readout.readout.• Optical pulser & scope (TDS6804) will be used to validate Optical pulser & scope (TDS6804) will be used to validate

electronics prior to test-beamelectronics prior to test-beam• Constant Fraction Discriminator+ HPTDC will be used to Constant Fraction Discriminator+ HPTDC will be used to

readout the detectorreadout the detector• Full sized prototype of detector available – but not all channels Full sized prototype of detector available – but not all channels

readoutreadout


• Design (Joint responsibility): Design (Joint responsibility): • Conceptual: geometry - Conceptual: geometry - barsbars, plates, block, fibers, other?), plates, block, fibers, other?)• OptimizationOptimization• EngineeringEngineering

• Simulation (Alberta + UTA):Simulation (Alberta + UTA):• full GEANT- 4 (Alberta), ray tracing (UTA)full GEANT- 4 (Alberta), ray tracing (UTA)

• Radiator (UTA + Fermilab):Radiator (UTA + Fermilab):• Fused silicaFused silica• Surface treatment: aluminization, cladding, ...Surface treatment: aluminization, cladding, ...

• Photodetector (UTA + Alberta)Photodetector (UTA + Alberta)• MCP-PMT: Hamamatsu, Burle, other? (Baseline solution)MCP-PMT: Hamamatsu, Burle, other? (Baseline solution)• SiPMT, Avalanche photodiode (APD)?, other ? SiPMT, Avalanche photodiode (APD)?, other ?

• Mechanics, Assembly and mounting (UTA, Alberta):Mechanics, Assembly and mounting (UTA, Alberta): • Engineering and manufacture (including motion control)Engineering and manufacture (including motion control)

• Electronics (Alberta + UTA)Electronics (Alberta + UTA)• Front end Read-outFront end Read-out• HV and slow controlsHV and slow controls

ResponsibilitiesResponsibilities


Funding InitiativesFunding Initiatives

UTA (with UofA listed as a collaborator):UTA (with UofA listed as a collaborator):Texas ARP $100K/2 years, TOF and Mechanics; Texas ARP $100K/2 years, TOF and Mechanics; passed University pre-proposal stagepassed University pre-proposal stage(12/79); proposal due Feb. 14, award May 15(12/79); proposal due Feb. 14, award May 15

DOE ADR $130k/2 years, TOF only, proposal dueDOE ADR $130k/2 years, TOF only, proposal dueDec. 15! Award date June. Burle is contributing Dec. 15! Award date June. Burle is contributing MCP-PMT’s 25MCP-PMT’s 25m pore (60 psec TTS), 10m pore (60 psec TTS), 10m porem pore(~30 psec expected), 10um, dropped face plate(~30 psec expected), 10um, dropped face plate(removes tail from recoil electrons), and high current (removes tail from recoil electrons), and high current capability versioncapability version

AlbertaAlbertaA small amount of initial funding is available(~$10K).A small amount of initial funding is available(~$10K).In kind contribution from small electronics and In kind contribution from small electronics and

machining costs (at 5CHF/hr!)machining costs (at 5CHF/hr!)


ConclusionConclusion

• The QUARTIC precision ToF detector offers the possibility of The QUARTIC precision ToF detector offers the possibility of reducing physics backgrounds to exclusive central Higgs reducing physics backgrounds to exclusive central Higgs production at ATLAS production at ATLAS

• ToF detector resolutions of ~10ps have been achieved ToF detector resolutions of ~10ps have been achieved previously and initial simulation studies indicate that we should previously and initial simulation studies indicate that we should be able to deploy a detector with resolution of better than 30ps be able to deploy a detector with resolution of better than 30ps at the LHCat the LHC

• This resolution will allow us to reduce the background from This resolution will allow us to reduce the background from events contributing central “activity” and two protons at 420m events contributing central “activity” and two protons at 420m (hard scatters + diffractive & double pomeron events) by more (hard scatters + diffractive & double pomeron events) by more than 90%.than 90%.

• The R&D effort to develop QUARTIC is well underway with the The R&D effort to develop QUARTIC is well underway with the first beam-test to take place in the summer of 2006.first beam-test to take place in the summer of 2006.


n=1 n>>1

Cerenkov EffectCerenkov Effect

Use this property of prompt radiation to develop a fast timing counterUse this property of prompt radiation to develop a fast timing counter

particle


Readout Electronics (1Readout Electronics (1stst take) take)


QUARTIC- A Precise ToF Detector for the FP420 Project James Pinfold For the QUARTIC Working Group...

Documents

Transcript of QUARTIC- A Precise ToF Detector for the FP420 Project James Pinfold For the QUARTIC Working Group...