Thermal simulation, CERN, 11 Nov 2002 Børge Svane Nielsen, NBI 1

FMD: Silicon multiplicity detectors

FMD: Silicon multiplicity detectors

Thermal simulation meeting,

CERN, 11 November 2002Børge Svane Nielsen

Niels Bohr Institute

1. Geometry of FMD, T0 and V0 detectors2. Material constants for FMD3. Heat dissipation of FMD

Thermal simulation, CERN, 11 Nov 2002 Børge Svane Nielsen, NBI 2

FWD detectors layoutFWD detectors layout

Thermal simulation, CERN, 11 Nov 2002 Børge Svane Nielsen, NBI 3

Si1, T0_r & V0_r layoutSi1, T0_r & V0_r layout

Thermal simulation, CERN, 11 Nov 2002 Børge Svane Nielsen, NBI 4

Si2 layoutSi2 layout

Thermal simulation, CERN, 11 Nov 2002 Børge Svane Nielsen, NBI 5

Si3, T0_l & V0_l layoutSi3, T0_l & V0_l layout

Thermal simulation, CERN, 11 Nov 2002 Børge Svane Nielsen, NBI 6

CERN maquette 1:1CERN maquette 1:1

Si1 (inner)Si1(outer)

V0-R T0-R

Absorber

ITS-pixels

Thermal simulation, CERN, 11 Nov 2002 Børge Svane Nielsen, NBI 7

FMD ring layoutFMD ring layout

256

Inner:

Rin=4.2 cm

Rout=17.2 cm

Outer:

Rin=15.4 cm

Rout=28.4 cm

20x2x128=5120

10x2x256=5120

128Full FMD =Full FMD = 3 inner rings +3 inner rings + 2 outer rings2 outer rings

Thermal simulation, CERN, 11 Nov 2002 Børge Svane Nielsen, NBI 8

Si1 assemblySi1 assembly

Si detectors

Support plates

Read-out electronics card on support plate back side

Thermal simulation, CERN, 11 Nov 2002 Børge Svane Nielsen, NBI 9

Hybrid with Viking chipsHybrid with Viking chips

VA preamp+shaper: 128 ch

Connector(s) forpower, control, read-out

Other components

Other components

Hybrid cards contain: FE chips Bias voltages distribution Gate/strobe distribution Read-out clock distribution Detector bias connection

Read-out cards contain: Bias voltages generation Gate/strobe distribution Read-out clock generation Remote connections

Si detector

Thermal simulation, CERN, 11 Nov 2002 Børge Svane Nielsen, NBI 10

FMD Material constantsFMD Material constants

Material type and thickness of one Si detector ring:

Layer Material ThicknessHeat

conductivity

(W/m·K)

Density

(kg/m3)

Specific heat

(J/kgK)

Silicon detector

Si 0.3 mm 84 2330 678

Hybrid Al2O3 0.5 mm 35 3970 880

FE electronics

air + chips10 mm

(mostly air)

SupportCarbon fibre or aluminium honeycomb

20.5 mm C or Al

+ 10 mm air

C: 24

Al: 222

C: 2200

Al: 2700

C: 691

Al: 900

Thermal simulation, CERN, 11 Nov 2002 Børge Svane Nielsen, NBI 11

FMD Material constantsFMD Material constants

Material type and thickness of one Si detector ring:

Layer Material ThicknessInteraction

lengthRadiation

length

Silicon detector

Si 0.3 mm 0.6 · 10-3 0.3 · 10-2

Hybrid Al2O3 0.5 mm 2.0 · 10-3 1.0 · 10-2

FE electronics

air + chips10 mm

(mostly air)

SupportCarbon fibre or aluminium honeycomb

20.5 mm C or Al

+ 10 mm air

C: 2.6 · 10-3

Al: 2.5 · 10-3

C: 0.5 · 10-2

Al: 1.1 · 10-2

Total thickness of one Si ring: C: 5.2 · 10-3 I 1.8 · 10-2 X0 Al: 5.1 · 10-3 I 2.4 · 10-2 X0

Thermal simulation, CERN, 11 Nov 2002 Børge Svane Nielsen, NBI 12

FMD electronicsFMD electronics

FMD channel count

Note: We are looking into increasing the number of strips, but use more integrated FE chips - red values.

In the following, I assume the new numbers.

Segments (wafers)

Phi sectors

Radial sectors

HybridsChips/

hybridFE chips FE channels

Si1 inner 10 20 (256) 512 10 (16) 8 (160) 80 (5,120) 10,240

Si1 outer 20 40 (128) 256 20 (8) 4 (160) 80 (5,120) 10,240

Si2 inner 10 20 (256) 512 10 (16) 8 (160) 80 (5,120) 10,240

Si2 outer 20 40 (128) 256 20 (8) 4 (160) 80 (5,120) 10,240

Si3 10 20 (256) 512 10 (16) 8 (160) 80 (5,120) 10,240

Total system 70 140 70 (720) 360 (25,600) 51,200

Thermal simulation, CERN, 11 Nov 2002 Børge Svane Nielsen, NBI 13

Heat dissipationHeat dissipation

Heat dissipated by FE electronics of one Si detector ring:

VA1TA preamp chip (128 channels): 150 mW 80 chips = 12 W / ring

For simulation: assume uniform distribution on hybrid surface (towards support plate)

Read-out electronics and power distribution: 5 W / ring

For simulation: assume concentrated in 2 locations near outer radius