GLD Overview

May 29, 2007

Y. Sugimoto

KEK

Baseline Design Large gaseous central tracker; TPC Large-radius, high-granularity ECAL with W/Scinti sandwic

h structure Large-radius, medium granularity, thick (~6) HCAL with P

b(Fe)/Scinti. sandwich structure Forward CAL (FCAL and BCAL) down to 5mrad Precision Si micro-vertex detector Si inner tracker (barrel and forward) Si endcap tracker Beam profile monitor in front of BCAL Muon detector interleaved with iron plates of the return yok

e Moderate magnetic field of 3T

Baseline Design

Return yoke design modified from DOD to reduce the total size of the detector and exp-hall size

0.05

4.5 7.5

0.40.6

2.3 2.8 4.2

0.45

2.02.1

3.54.04.5

7.2

Main TrackerEM CalorimeterHadron CalorimeterCryostat

Iron YokeMuon DetectorEndcap Tracker

2.5

Baseline Design

TPC

FCAL

ECAL

VTX

ET

SIT

10 cm

10 cm

HCALcos=0.9

BCAL

Baseline Design

Back-scattering from BCAL should not hit

TPC directly

Q

TPC

CH2 Mask

BCAL

FCAL

R=45cm

Z=230cm

Z=450cm

Z=230cm

Pair Background

Detector Parameters VTX

6 layers (3 doublets) R=20(18) mm – 50 mm Fine pixel CCD as the baseli

ne design SIT

DSSD, 4 layers,R=9 - 30 cm 7 discs in forward region, Z=

15.5 - 101.5cm Bunch ID capability

TPC R=45 cm – 200 cm Z=230 cm

~5mm

z=350mmz=250mm

Core of Pair-Background

17mm

15mm 2mm

5mm

~2mm

Si wafer Beam PipeRVTX

ZVTX

RS

RBe Rcore

Detector Parameters ECAL

W/Scintillator/Gap = 3/2/1 mm 33 layers 1cmx4cm scintillator strips, w.l.s. fiber+MPPC (SiPM) readout 2cmx2cm scintillator tile as an option 26 X0, 1

HCAL Pb(Fe)/Scinti./Gap = 20/5/1 mm 46 layers 1cmx20cm scintillator strips + 4cmx4cm scintillator tile, w.l.s. fibe

r+MPPC readout 5.7

Muon detector 8/10 layers in 4-cm gaps between 25-30 cm thick iron slabs of ret

urn yoke X-Y scintillator strips with w.l.s.fiber+MPPC readout

Detector Parameters PFA

GLD LDC SiD

B (T) 3 4 5

RCAL (m) 2.1 1.6 1.27

ptmin in CAL (GeV/c) 0.95 0.96 0.95

B R2CAL (Tm2) 13.2 10.2 8.1

tHCAL () 5.7 4.6 4

Estore (GJ) 1.6 1.7 1.4

RFe (m) 7.2 6.0 6.45

Why is GLD large?

How much iron do we need? B-field calculation based on

a toy model using a FEA program was done

BR2, tECAL, tHCAL, G1, G2; fixed

Leakage field at Z=10 m was estimated as a function of B, and tFe

tFe to satisfy the leakage limit of 100G was obtained for each B

RCAL tECAL

tHCAL

G1+G2tFe

RFe

G1G2

5 cm

40 cm

Leakage B-field GLD-like

BR2=13.23 tECAL=0.17m

tHCAL=1.23m G1=G2=0.5m

tFe (m)

BZ

=10

m

Leakage limit Andrei put the limit to 50G, but 100G can be reduced to <50G by low cost Helmholtz coil

0

50

100

150

200

250

300

1.9 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3 3.1 3.2 3.3 3.4 3.5

2.5T3T3.5T4T4.5T5T5.5T

Leakage B-field LDC-like

BR2=10.24 tECAL=0.17m

tHCAL=1.13m G1=0.46m G2=0.49m

tFe (m)

BZ

=10

m

0

50

100

150

200

250

300

350

1.5 1.6 1.7 1.8 1.9 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3 3.1 3.2 3.3 3.4

2.5T3T3.5T4T4.5T5T5.5T

Leakage B-field SiD-like

BR2=8.06 tECAL=0.13m

tHCAL=1.09m G1=0.21m G2=0.63m

tFe (m)

BZ

=10

m

0

50

100

150

200

250

300

350

1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 2.1 2.2 2.3 2.4 2.5 2.6

2.5T3T3.5T4T4.5T5T5.5T

B and R

0

1

2

3

4

5

6

7

8

2 3 4 5 6

RcalRout

0

1

2

3

4

5

6

7

2 3 4 5 6

RcalRout

0

1

2

3

4

5

6

2 3 4 5 6

RcalRout

R (

m)

B (T)

GLD-like LDC-like SiD-like

For a given BR2, larger B (smaller RCAL) gives larger detector size

B and Cost

GLD-like detector model Unit cost assumption

ECAL: 6.8M$/m3

HCAL: 0.16M$/m3

Fe: 42k$/m3

Solenoid: 0.523x[Estore]0.662 M$

0

50

100

150

200

250

300

2.5 3.5 4.5 5.5

C-ECALC-HCALC- FeC- solC- total

B (T)

Cos

t (M

$)

B-field dependence of the total cost (CAL+Sol.+Fe)

is very small

Summary

GLD is the largest detector among the three PFA detectors

GLD is the largest NOT because it has the largest inner radius of the calorimeter, but because it has the largest BR2, the thickest HCAL, and the smallest leakage field