LHCC meeting, CERN, 22 Nov 2004 Børge Svane Nielsen, NBI 1

FMD: Forward multiplicity detectors

FMD: Forward multiplicity detectors

LHCC referees meeting, CERN, 22 November 2004

Børge Svane Nielsen

Niels Bohr Institute

1. Material in front of FMD: ITS services2. Material in FMD, in front of e.g. PMD3. Radiation tolerance of detector and electronics4. Recent progress on sensors and electronics5. Temperature environment of FMD

LHCC meeting, CERN, 22 Nov 2004 Børge Svane Nielsen, NBI 2

FMD2+3 layoutFMD2+3 layout

PMD acceptance limit

LHCC meeting, CERN, 22 Nov 2004 Børge Svane Nielsen, NBI 3

FMD material countFMD material count

Al honeycombsupport plate

Hybrid

Si sensor

Layer MaterialThickness

(cm)

Density

(g/cm3)Interaction

lengthsRadiation lengths

Silicon detector Si 0.03 2.33 0.7 · 10-3 0.3 · 10-2

Hybrid FR4 0.1 1.7 1.9 · 10-3 0.5 · 10-2

Digitizer card FR4 0.1 1.7 1.9 · 10-3 0.5 · 10-2

Support plate Aluminium 20.05 2.7 2.5 · 10-3 1.1 · 10-2

Total thickness of one Si ring: 0.7 10-2 X0 2.4 10-2 I

LHCC meeting, CERN, 22 Nov 2004 Børge Svane Nielsen, NBI 4

FMD in AliRoot FMD in AliRoot

LHCC meeting, CERN, 22 Nov 2004 Børge Svane Nielsen, NBI 5

AliRoot material simulationsAliRoot material simulations

Radiation length maps

LHCC meeting, CERN, 22 Nov 2004 Børge Svane Nielsen, NBI 6

AliRoot material simulationsAliRoot material simulations

Radiation length mapInteraction length map

... consistent with background conditions used in TDR

LHCC meeting, CERN, 22 Nov 2004 Børge Svane Nielsen, NBI 7

VA1 radiation hardnessVA1 radiation hardnessRadiation tests of VA1 by Belle collaboration:

Yokoyama et al, IEEE Trans Nucl Sci 48 (2001) 440

LHCC meeting, CERN, 22 Nov 2004 Børge Svane Nielsen, NBI 8

RCU locationRCU location

RCU

FMDD

DAQ

Patch panel

“TPC” Front-end busand Control bus

~ 3 m

LHCC meeting, CERN, 22 Nov 2004 Børge Svane Nielsen, NBI 9

Error estimates per run

High Energetic Hadron Flux (@ TPCin): 250 – 550 hadrons / sec •

cm2

Error rate per run (4 hours) per device

FEC 3•10-4

RCU 1.5•10-2

DCS 3•10-2

SEU in RCUSEU in RCU

L.Musa:

1–5•10-3 @ FMD

LHCC meeting, CERN, 22 Nov 2004 Børge Svane Nielsen, NBI 10

Measurements of VA1-ALICEMeasurements of VA1-ALICE

Linearity better than 2.5% in required dynamic range (70 fC). Possible tomeasure to at least 100 fC.

Setup not well shielded. Average noise level around 175e-.

Noise measurement, 128 channels

LHCC meeting, CERN, 22 Nov 2004 Børge Svane Nielsen, NBI 11

Hybrid and sensor layoutHybrid and sensor layout

IDEAS

Hamamatsu

LHCC meeting, CERN, 22 Nov 2004 Børge Svane Nielsen, NBI 12

Electronics integration test in progress

Electronics integration test in progress

Si-strip detector + VA1 read-out

VA1 read-out controller

Analog signal receiver

ALTRO test board

Digitized ALTRO output of 128 pulsed VA1 channels

BSN, 17/11/2004

128 VA1 channels into 1 ALTRO

First few VA1 channels. 8 digitizings per channel.

LHCC meeting, CERN, 22 Nov 2004 Børge Svane Nielsen, NBI 13

FMD heat dissipationFMD heat dissipation

Heat dissipated by FE electronics of one Si detector ring:

VA1_ALICE preamp chip (128 channels): 125 mW (measured) 80 chips = 10 W / ring

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

Total per ring: 15 W

Total per FMD2/FMD3: 30 W

LHCC meeting, CERN, 22 Nov 2004 Børge Svane Nielsen, NBI 14

Thermal simulationsThermal simulationsA. Mueller:

LHCC meeting, CERN, 22 Nov 2004 Børge Svane Nielsen, NBI 15

LHCC meeting, CERN, 22 Nov 2004 Børge Svane Nielsen, NBI 16

Signal/background in FMD Signal/background in FMD

FMD3 outer

FMD3 inner FMD2 inner

FMD1

Primaries

Beam pipe

ITS and services

T0, V0, Absorber, frames