GLC Detector Geometry

Y. Sugimoto

Introduction

Figure of merit : Main Tracker

samplings ofNumber :

length Tracking :

field Magnetic :

resolution Spatial : 4

7203.3/ )( 2

2

n

L

B

nBLtp

tp

Figure of merit : Calorimeter jet

2 = ch2 +

2 + nh2 + confusion

2 + threashold2

Separation of charged particles and /nh is important (See J.C. Brient’s talk at LCWS2004)

Charged particles should be spread out by B field Lateral size of EM shower of should be as small as possi

ble ( ~ Rmeffective: effective Moliere length)

Barrel: B Rin2/ Rm

effective

Endcap: B Z2/ Rmeffective

Rin : Inner radius of Barrel ECAL

Z : Z position of EC ECAL front face

(Actually, it is not so simple. Even with B=0, photon energy inside a certain distance from a charged track scales as ~R i

n2)

Simulation by J.C. Brient

SD (6T)

TESLA (4T)

e+e- ZH jets at Ecm=500GeV

Effective Moliere Length

Absorber W : Rm ~ 9mm Pb : Rm ~ 16mm

Gap : Sensor + R.O. elec + etc.

xa xg

Effective Molire Length = Rm (1+xg/xa)

B=0

Comparison of Detector Models

SD TESLA GLC LD JLC

Solenoid B(T) 5 4 3 3 2

Rin(m) 2.48 3.0 3.75 3.7 4.25

L(m) 5.8 9.2 6.8 9.4 9.1

Est(GJ) 1.4 2.3 1.0 1.7 1.1

Tracker Rmin (m) 0.2 0.36 0.45 0.5 0.45

Rmax(m) 1.25 1.62 1.55 2.0 2.3

m 7 150 85 150 100

Nsample 5 200 50 144 100

pt/pt2 3.9e-5 1.5e-4 2.9e-4 1.6e-4 1.3e-4

Comparison of Detector Models

SD TESLA GLC LD JLC

ECAL Rin(m) 1.27 1.68 1.6 2.0 2.5

ptmin 1.9 2.0 1.4 1.8 1.5

BRin2 8.1 11.3 7.7 12.0 12.5

Type W/Si W/Si Pb/Sci Pb/Sci Pb/Sci

Rm(mm) 18 24.4 25.5 21.3 21.3

BRin2/Rm 448 462 301 565 588

Z 1.72 2.83 2.05 3.0 2.9

BZ2/Rm 822 1311 494 1271 792

X0 21 24 27 29 29

Total 5.5 5.2 7.3 6.9 6.9

t (m) 1.18 1.3 1.8 1.7 1.5

Possible modification of GLC Detector Larger Rmax of the tracker and Rin of ECAL Keep solenoid radius same: Somewhat thinner CAL (but still 6), but does it matter? Use W/Sci(/Si) instead of Pb/Sci for ECAL

Effective Rm: 25.5mm 16.2mm (2.5mm W / 2.0mm Gap) Much smaller segmentation by Si pad layers

Put ECCAL at larger Z Longer Solenoid Preferable for B-field uniformity if TPC is used

If l*=4.3 (3.5) m is adopted, 10 cm thick W shield around the support tube is not necessary

Rmin of the tracker can be reduced It is preferable Zpole-tip < l* both for neutron b.g. and QC support

GLC B-field non-uniformity

mm

Z (m)

TESLA TDR Limit

R=0.1m

R=2.0m

TESLA TDR Limit: mm 2max

0

dzBz

Brz

by H.Yamaoka

Comparison of Detector Models

SD TESLA GLD LD JLC

Solenoid B(T) 5 4 3 3 2

Rin(m) 2.48 3.0 3.75 3.7 4.25

L(m) 5.8 9.2 8.4 9.4 9.1

Est(GJ) 1.4 2.3 1.2 1.7 1.1

Tracker Rmin (m) 0.2 0.36 0.40 0.5 0.45

Rmax(m) 1.25 1.62 2.05 2.0 2.3

m 7 150 150 150 100

Nsample 5 200 220 144 100

pt/pt2 3.9e-5 1.5e-4 1.1e-4 1.6e-4 1.3e-4

Comparison of Detector Models

SD TESLA GLD LD JLC

ECAL Rin(m) 1.27 1.68 2.1 2.0 2.5

ptmin (GeV/c) 1.9 2.0 1.9 1.8 1.5

BRin2 8.1 11.3 13.2 12.0 12.5

Type W/Si W/Si W/Sci/Si Pb/Sci Pb/Sci

Rm(mm) 18 24.4 16.2 21.3 21.3

BRin2/Rm 448 462 817 565 588

Z 1.72 2.83 2.8 3.0 2.9

BZ2/Rm 822 1311 1452 1271 792

X0 21 24 27 29 29

Total 5.5 5.2 6.0 6.9 6.9

t (m) 1.18 1.3 1.4 1.7 1.5

EM Calorimeters

Area of EM CAL (Barrel + Endcap) SD: ~40 m2 / layer TESLA: ~80 m2 / layer GLD: ~ 100 m2 / layer (JLC: ~130 m2 / layer)

Global Geometry

Global Geometry

Interaction Region

Summary

The LC detector optimized for “Energy Flow Algorithm” is realized with a “Truly large detector”

“Truly large detector” can be achieved with a minimal modification of GLC detector, and it can get better performance than any other detector models.

Compared with the present GLC detector, Rmin and Zmin of EM CAL should be increased Effective Moliere length of ECAL should be decreased Magnetic field and radius of the solenoid unchanged, but somewhat l

onger For TESLA detector, it is hard to make Rmin of ECAL larger bec

ause of the cost of the Si/W EMCAL The key is Calorimeter

Summary (Cont.)

Things to do: Design new (longer) solenoid magnet with better uniformity TPC: Determine the requirement for the B-field uniformity CAL: Simulations

Show the advantage of Large detector 4 cm2 granularity is good enough for EFA? If not, how many Si layers are necessary? Consider tungsten (W) instead of lead (Pb) Or still stick to hardware compensation rather than EFA? How many ’s needed?

Collaboration with US LD: GLC+LD = GLD