specific interests of german groups

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Specific interests of German groups

General detector development plans

Aachen IIIA / IIIB and DESY collaboration

Associated work

First steps

Jens [email protected]. Physikalisches Institut ARWTH Aachen University

CMS Upgrade Workshop at FNAL, 2008/11/19 to 2008/11/21Muon Detector Working Group, Thursday, 2008/11/20 09:40

Hardware development for a scintillator based MTT

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Muon fast Track Tag

muon tag

muon system+ absorption by calorimeter and coil - tracks affected by multiple scattering + redundancy given by RPCs

tracker- huge number of tracks+ precise p

t measurement

(high resolution, less material, strong B-field)

calorimeter

tracker

idea: Bologna

one option: use scintillator based MTT

by A. M

ontanari

also Aachen III, DESY

use a new part of muon system (MTT) to select an interesting region in the

tracker in L1-trigger

general detector development plans

in addition to Bologna

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MTT design – German focus

based on the MTT idea including dimensions developscintillator detector

German groups focusing on detector development and building(long tradition in Aachen)


(slide 18 from Pierluigi`s talk)

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MTT hardware – dedicated technologyIdea: Scintillator based MTT readout by SiliconPhotoMultipliers

maintenance free no gas needed very fast any requested resolution

possible

no HV needed (Usupply

< 100 V) less power needed (< 0.2 mW/mm2) very good timing (100 ps to 1 ns) high photon detection efficiency (up to 65 %) but high noise rate (up to 1 MHz/mm2 at 0.5 PE threshold) and small active surface (up to 3 mm x 3mm at the moment)

Hamamatsu SiPM: 100 µm x 100 µm pixels

Best suited device for triggering at the moment:- highest photon detection efficiency - low noise - will soon be produced in CMOS technology (cheap)


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Aachen IIIA: - simulations about light collection /SiPM signal timing - combining MTT with muon chamber Aachen IIIB: - experience from tracker development - SiPM supply electronics development

Aachen IIIA + Aachen IIIB: (finally) building the MTT

DESY: HCAL group member, possible integration with HO


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MTT at Aachen IIIA – Scintillator designsTwo possible designs:

“Traditional” one:scintillator plates with embedded WaveLengthShifting fibers

+ light collecting in WLS fiber → more light/photon detector surface - mechanical efforto good time resolution

“New” one:SiPMs directly mounted to scintillator plates (was done with huge PMs)

o low light yield - but readout perhaps possible (high pde, large SiPMs (~ price as smaller ones)+ simple mechanical construction+ very good time resolution- maybe more readout channels, power consumption

scintillator (blue light)WLS fiber(green light)

photon detectors

Aachen


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diffuse reflection

“normal” reflection

total reflection

MTT at Aachen IIIA – Light collection studies


Aachen IIIA cosmics testing (student project)

- try to find best position of SiPMs, wrapping of scintillator, shape of WLS fiber

- have developed “standalone“ scintillator + SiPM simulation

- diploma student is working on GEANT simulation

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MTT at Aachen IIIBAachen IIIB brings in experience from tracker (petals) assembling / testing:

- one focus: development of compact SiPM readout electronics

- especially: development of a gain stabilization on a chip (SiPM gain is temperature and maybe time and radiation dose dependent)

Aachen IIIB SiPM-cosmics testing


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timing (kind of coincidence, time resolution)

(trigger) electronics tests

build large test detectors

tests together with other detectors (muon chamber, petal)

MTT test detector

muon chamber

tracker petal

cosmic m

uon

cosmic m

uon

MTT at Aachen – common Aachen IIIA/B parts

CMS silicon petal quality control at Aachen IIlB


SiPM mounted on Aachen pcb, first test with scintillator

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MTT at DESY


- DESY member of HCAL group (CASTOR)

- interested in combination MTT with HO

- change of HPD in SiPM for HO needed → exchange of initial two readout-boxes planned for this shut down → get experience with the longterm operation with SiPM (new detector technology, also at T2K starting 2009)

- further discussion between Muon and HCAL groups underway, need experiences with HO with SiPMs and for sure simulations everywhere

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Associated work

associated work

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Implementation of MTT into CMSSW

scintillator can probably not distinguish between kinds of particles

scintillator does not measure momenta

MIP produce less light than background (e.g. slow protons, electrons)

background rate of all (charged) particles including low momentum particles

timing of background (and signal)

momentum of background particles (absorbing / producing secondary particles)

Scintillator very sensitive to background !

associated work

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Absorber (thin, between 2 scintillator layers):Absorbs low momentum particles between the two layers.→ MTT gets too thick ? Two layers too expensive ?

Use multiple scattering/magnetic field deflection → Does not work with one MTT element.

Set time-of-flight gate:Reduce sensitivity to neutron background, slow pions and kaons → Need high time resolution, more electronics ?

Set pulse height amplitude (=amount of light) limit:(background produces mostly more light than MIPs)

Combination with HO

Strategies to limit sensitivity of MTT to background

associated work

MTT layer 1

MTT layer 2absorber (Pb)

slow e-

neutron induced proton

pion

new particles

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First steps

first steps

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Simplest scintillator based detector

100 mm

SiPMs (3 mm x 3 mm) in unconventional position

idea

: T.H

. for

SL

HC

+ very simple set up

+ thin construction

+ very good time resolution

- a lot of SiPMs needed

- many readout channels (but high resolution)

SiPMs directly coupled to front side of a piece of scintillator

Aachen

first steps

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Simulation results (2)

first steps

4 PE threshold

Assuming: - 90 % diffuse reflexion at surrounding 3M tape - 3 mm x 3mm detectors - 65 % photon detection efficiency (80 % coupling efficiency)

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Simulation results (2)

efficiency > 80 % for 10 mm thick scintillators

(gets ~ 100 % for 95 % reflective wrapping)

(to be tested with larger scintillators)

first steps

need 2 of 4 coincidence(4 PET for each SiPM)

noise rate < 1 Hz

no correlation with no correlation with SiPM position visibleSiPM position visible

position of SiPM

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Simulation for WLS fiber setup (1)

first steps WLS fiber simulation

100

100

10

piece of scintillator (BC-404)

WLS fiber (BCF-92)

SiPMs (Hamamatsu 100 pixels, 1 mm x 1 mm)

- uniform distributed, vertical particle transition- require coincidence (interval < 10 ns) between both SiPMs with 3 PET→ noise rate < 1 Hz

)

simulated 10000 muons traverses

µ

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first steps

Simulation for WLS fiber setup (2)

light collection effect of WLS fiber huge

more than 98 % detection efficiency (using 1 mm x 1 mm SiPMs)

time resolution of detector still good

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Conclusion MTT is a promising concept to include tracker data into L1 muon trigger: - DT and RPC can be kept as independent systems. - MTT can also solve DT occupancy problem (at L1-trigger).

Scintillator based MTT could be an easy and cheap solution: - It can be inserted in addition to existing detectors. - SiPMs are a very promising technology. - German groups can contribute to detector development and building. - MTT/HO: under discussion, several aspects to be clarified

At SLHC may need any kind of redundancy !

conclusion

specific interests of german groups

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