f. grancagnoloilc workshop valencia , 8 . 11 . 2006

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F. Grancagnolo ILC Workshop Valencia , 8 . 11 . 2006

ILC Workshop - ECFA and GDE Joint Meeting

Valencia, 5-13 November 2006

F. Grancagnolo, INFN - Lecce

The Muon System of

the 4th Concept Detector

at

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4th Concept Detector Layout

Triple-readout fiber calorimeter: scintillation/Cerenkov/neutron Muon dual-solenoid iron-free geometry

6.4 m

7.7 m

NOVEL FEATURES:

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TPC

- BARREL

-E CN AD P

Dual Solenoid B-fieldAlexander Mikhailichenko design

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-System basic element: drift tube

radius 2.3 cm filled with 90% He – 10% iC4H10 @ NTP gas gain few × 105

total drift time 2 µs primary ionization 13 cluster/cm ≈ 20 electrons/cm total both ends instrumented with:

• > 1.5 GHz bandwith• 8 bit fADC• > 2 Gsa/s sampling rate• free running memory

for a • fully efficient timing of primary ionization: cluster

counting• accurate measurement of longitudinal position with

charge division • particle identification with dNcl/dx

ASIC chipunder

developmentat INFN-LE

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Cluster Countingfull vertical scale = 30 mV (amplification x10)horizontal scale = 500 ns/divsampling rate = 2.5 Gsa/s

2 cm tube

gas:

90% He + 10% iC4H10

Ncl = 13./cm Nele = 20./cm

Max drift time

1.3 s

50 ns5 mVleft

right

trigger

Cosmic ray triggeredby scintillators telescope

and read out by adigital sampling scope:8 bit, 4 GHz, 2.5 Gsa/sAmplifier bandwith:1.8 GHz, gain ×10

t0 tlasttfirst

1.3 s


t0

tfirst

t0 = tlast tmax

bf = ∫ v(t) dt

(c/2)2 = r2 bf2

Ncl = c/(× sin

Nele = Ncl × 1.6

tlii=1,Nele ;trii=1,Nele

Alii=1,Nele ;Arii=1,Nele Pi(cl)i=1,Nele

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Cluster Counting Cluster Counting Performances (1)Performances (1)

b

b

from KLOE

Transverse spatial resolution In principle,given the time ordered sequence

of the drifting clusters, each cluster contributes to the

impact parameter with an independent estimate.

b = bi √Ncl

(saturated by other conributions,like position and sag of sense wire)

In reality,multiple electron clusters andsingle electron diffusion tend

to confuse the picture.

For Ncl = 13 /cm is reasonable to assume: xy ≈ 50 m


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≈ 200 mrad


Longitudinal spatial resolution

Estimate of dip angleNcl = c/ × 1./sinFor an average c and a minimum ionizing track, Ncl = 40

(a few mm extrapolation from one layer to next) extremely powerful tool for 3D track finding!


Matching left and right sides gives a very precise measurement of the signals transit timeon the wire(limiting factor for time-to-distance conversion) and enhances signal/bkgd.After matching, charge division can be applied to single electrons amplitudes A li and Ari.In principle: z/L = 0.5% / √Nele

Well below 1 mm/m of wire

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Transverse momentum resolution

Assume: l = 1.5 m b = 50 m B = 1.5 T n= 20 layers


Equal contribution at p=53 GeV/c, when p/p= 2%, or p= 1.2 GeV/cIn the end cap one would need the map of B-field and MC calculations.However, resolutions like:

p/p = 1.4 × 10-3 p 1.4 × 10-2

(end caps)are reachable

p/p = 3.0 × 10-4 p 1.6 × 10-2

(barrel)

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Cluster Counting Cluster Counting Performances (4)Performances (4)Particle identification

It might not be necessary in the -system. However, for a m.i.p.

(a m.i.p. track in the -system generates approximately 1200 clusters)(dNcl/dx)/(dNcl/dx)

≈ 3%

Example from test beam data: sepration @ 200 MeV/c

G.Cataldi, F.Grancagnolo and S.Spagnolo, INFN-AE-96-07, Mar. 1996, 23p.G.Cataldi, F.Grancagnolo and S.Spagnolo, NIM A386 (1997) 458-469


Equivalent to: separation ≿ up to 25 GeV/c, ; ≿ up to 55 GeV/c ; ≿ up to 100 GeV/c separation ~ up to 5 GeV/c

(CAVEAT: No data available!, Calculation based on Bethe-Block only!)

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beam test m

easurements

p = 200 GeV/c

gas mixture = 95%He+5%iC4H10 Ncl = 10/cm

atMeV/c

experiment:

theory: trunc. mean:


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tmax

(tmax) ~ 1 ns

Drift time of last arriving electroncorrected for t.o.f. and for transit time on the wire.Assumed 10 tracks with 100 hits each.

From tmax one gets t0 event by event,avoiding long and complicated calibration procedures.

Moreover,(t) ~ 1 ns identifies the trigger of the event


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Drit tube end plug detail

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×18

×36

×18

Modularity

650 tubes

26 cards

550 tubes

22 cards

1750 tubes

70 cards

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×3

10500 tubes

420 cards

1/3 barrel

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1440 tubes 1632 channels

76 cards

×6

1/3 end cap

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×2

End cap

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Full -system

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Channel count Barrel:

31500 tubes21000 channels 840 cards

End caps: 8640 tubes 9792 channels 456 cards

Total:40140 tubes30792 channels 1296 cards

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+ − at 3.5 GeV/c

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50 GeV jet with escaping

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80 GeV jet with escaping particles

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80 GeV jet with escaping particles

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Cluster CountingCluster Counting90% He + 10% iC4H10

91% Ar + 5% iCH4 + 4% N2

cylindrical tube r = 2 cm

at a gain = few × 105

time separation (MC) between

closest clusters as a function

of their distance from the sense wire for different

track impact parameters

In HeIn Ar

In He , provided that: rise (and fall) time of single electron signals < 1ns sampling frequency of electron signals > 2 Gsa/s single electron counting is possible. CAVEAT:Multiple electron clusters (30% in this He mixture) complicates the picture


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Cluster Counting Time separation (MC) between closest ionization

clusters along a track as a function of their distance from the sense wire for different track impact

parameters

In He , provided that: rise (and fall) time of single electron signals < 1ns

sampling frequency of electron signals > 2 Gsa/s

single electron counting is possible. CAVEAT: Multiple electron clusters (30% in this He mixture) complicates the picture

cylindrical tube

r = 2 cmgain = few ×

105

91% Ar + 5% CH4 + 4% N290% He + 10% i-C4H10


f. grancagnoloilc workshop valencia , 8 . 11 . 2006

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