AGENDA - ALICE Forward Detectors

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ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

1

Forward detector
overview


Si
-
FMD (Forward Multiplicity Detector) NBI+INR

o
Si
-
strip Ring counters (5) with >50.000 channels

o
-
5.1<



-
ㄮ㜻1
ㄮ㜼1


㰠㌮<

o
Precise off
-
line charged particle multiplicity for A+A, p+p

o
Fluctuations event
-
by
-
event, flow analysis


T0 (Beam
-
Beam Detector) Jyvæskyla + MEPhI, INR, Budker, Kurchatov

o
2 arrays of 12 Cerenkov radiators + PM tubes

o
-
5<



-
㐮㔻4㈮2



㰠㌮3

o
Fast timing LVL0 signal (

㴵ば猩s l楮i 癥牴數v摥瑥牭楮慴楯i

o
Main time reference and backup for MinBias trigger


V0 (Centrality and collision vertex) Lyon+Mexico

o
2 arrays of plastic scintillator tiles w. fiber+PMT

o
-
5.1<



-
㈮㔻2
ㄮ㜼1


㰠㌮<

o
Main LVL0 MinBias for p+p and A+A and centrality trigger A+A

o
Background rejection

ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

2

Forward detectors

T0
R

2.9 < |

| < 3.3

T
0

for the TOF (< 50 ps time res.) Two arrays of
12 quartz counters.

Also backup to V0

SI
-
FMD

Multiplicity and dn/d


1.7 <

< 3.4 and
-
5.1 <

<
-
1.7

Silicon pad detector disks (slow readout)

V0

1.7 < |
|
< 3.8

and

5.1 < |


| <
-
2.5

Interaction trigger, centrality trigger and beam
-
gas rejection. Two arrays of 72 scintillator tiles
readout via fibers

T0
L

PMD
pre
-
shower det.


ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

3

Integration in ALICE

Si
-
1

Si
-
2

Si
-
3

V0
-
R

T0
-
R

ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

4

FWD detectors

ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

5

CERN Maquette 1:1

Si1 (inner)

Si1(outer)

V0
-
R


T0
-
R


Absorber

ITS
-
pixels



ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

6

Si
-
FMD

Overall Geometry


-
5.1<


<
-
ㄮ㜠



3.4 <


㰠ㄮ7

Si3

Si2

Si1

ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

7

Si rings manufactured
of 6” wafers

256

Inner:

Rin=4.2 cm

Rout=17.2 cm

Outer:

Rin=15.4 cm

Rout=28.4 cm

10x2x256=5120

20x2x128=5120

128

ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

8

Coverage in
pseudorapidity

Constraints:

Vacuum tube outer envelope: 42 mm,

Outer radius, ITS, Absorber, cables

Background from secondaries(small angles)

Design criteria:

Largest possible


捯v敲eg攠

La牧敳琠symme瑲t 汥晴la湤⁲楧桴

Overlap between systems

Si1:

Out:

1.70<

㰲⸲.


In:

2.01<

㰳⸴.

卩S:

Out:

-
2.29<

<
-
1⸷

In:

-
3.68<

<
-
2⸲.

卩S:

In:

-
5.09<

<
-
3⸶.


Vertex shift
(10cm): |d

|


0.1



ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

9

Charged particle occupancy
including secondaries

20


sectors

256 strips each

5120 channels

20


sectors

256 strips each

5120 channels

40


sectors

128 strips each

5120 channels

May increase number of strips by factor of 2 or 3 using ’128 ch VA
-
prime’

PA chip at same cost !

ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

10

Multiplicity resolution

ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

11

Hybrid with Viking PA
chips

VA preamp+shaper: 128 ch

Connector(s) for

power, control, read
-
out

Hybrid cards contain:



FE

Preampl. chips



Bias voltages distribution



Gate/strobe distribution



Read
-
out clock distribution



Detector bias connection

Si detector

ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

12

Front end electronics

REQUIREMENTS:


Adapted for 5
-
25pF capacitance

(300

m 卩Ⱐ0⸵ 捭2㨠25灆Ⱐ
1MIP: 22.400 e
-
)

Dynamic range: 0
-
20 MIPS

Radiation hardness: >200kRad

Peaking time: 1
-
2

s

L潷 n潩o攠⡧潯搠⽎)

High integration

Sample/hold and serial read
-
out, 10 MHz clock

Moderate power consumption

Simple slow controls and power
reg.

Affordable cost


VA1 prime 2 (Viking
-
IDEAS):

Input capacitance: < 30 pF



0
-
20 MIPs

>1MRad (0.35

洠m散栮e

1
-


s

475 e
-

慴′a 灆p=> 匯丠S0㨱

128

10 Mhz clock


1.3 mW/ch

Test system available


OK

ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

13

FMD RO strategy

FMD Segment

ON DETECTOR

Digital serial


links

(15
-
20 m)

Trigger &
Slow Ctrl

IN CAVERN

IN

COUNTING

ROOM

Slow control

& Trigger

Detector
Data Link

(50
-
60 m)

FMD RCU

VA

1 ring: 10/20 segments 2 Digitizers 1 R
CU
per side 1 DDL per side

Full FMD: 70 segments 10 Digitizers

2

RCU’s 2 DDL’s

FMD Read
-
Out and Control Electronics

Analog serial link

(10 MHz)



0.5 m

噁牥a
-
o畴

捯湴nol

Local

Controller

DDL
-

INT

Slow
-
Control

Interface

TTC
-
RX

BOARD

CTRL

Data

receiver

FMD Digitizer

ALTRO

ALTRO

ALTRO

CTRL

Read
-
out CTRL

CTRL

CTRL

BSN, 21 Nov 2002

ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

14

FMD FEE test setup

BSN, 21 Nov 2002

FMD FEE test

CTRL

Power

Biases

Clock

10 MHz

Trig in

ALTRO tester

ALTRO

CTRL

Ext clock

Ext trigger

Si

detector

VA

Labview


DAQ

ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

15

Si
-
FMD timetable (1)

A

FRONT END (FE) READ OUT ELECTRONICS

Completed

1

Demonstrate functionality of conceptual layout of FEE

(Viking PA chip, control system, interface to ALTRO test board)

April 1 2003

2

Final choice of VA pre
-
ampl. chip. RO test

June 1, 2003

3

Test FEE system coupled to sample Si detector. Source and
electron beam tests.

June 1, 2003

4

Design, construction and test of prototype FMD digitizer card
(FMDD), RO test with ’mini’ FMD
-
RCU

October 1, 2003

5

Full Si detector element + electronics chain RO with realistic
RCU and DDL link to DAQ.

June 1 , 2004

B

MECHANICS AND INTEGRATION

Completed

1

Full scale model manufactured (Si1)

February 1, 2003

2

Cabling and Cooling issues resolved

April 1, 2003

3

Full integration sequence decided

June 1, 2003

ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

16

Si
-
FMD timetable (2)

C.

SILICON DETECTOR

Completed by

1

Complete market survey

February 1, 2003

2

Define final specs

March 1, 2003

3

Place order for prototype with industry

April 1, 2003

4

Delivery Si
-
wafer prototype

June 1, 2003

5

Start production of Si
-
hybrid FEE card

June 1, 2003

6

Delivery prototype hybrid

August 1, 2003

7

Si prototype test with FEE and BEE test RO setup

December 1,
2003

8

Place final order for Si with industry

April1, 2004

ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

17

V0 detector


Two segmented scintillator
hodoscopes on either side
of IP



Minimum bias trigger:

p
-
p
and Pb
-
Pb


Main on
-
line LVL0
centrality trigger:

Pb
-
Pb


Background filter
for the
dimuon spectrometer


Two arm for
beam
-
gas
rejection


Luminosity

control


Multiplicity
measurement
(high occupancy)



V0
-
R

Absorber

ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

18

V0 Segmentation


V0
-
L and V0
-
R: 5 rings each



Rings 1
-
4: 30
°

sectors (12)


Ring 5: 15
°

sectors (24)



Rings 1
-
3 are in the dimuon arm acceptance

Ring

V0L

V0R

η
max
/
η
min


max
/

min

η
max
/
η
min


浡x
/

min

1

-
5.1/
-
4.6

-
0.7/
-
1.2

3.8/3.4

2.6/3.8

2

-
4.6/4.2

-
1.2/
-
1.7

3.4/2.9

3.8/6.3

3

-
4.2/
-
3.7

-
1.7/
-
2.8

2.9/2.5

6.3/9.4

4

-
3.7/
-
3.2

-
2.8/
-
4.7

2.5/2.1

9.4/14.0

5

-
3.2/
-
2.8

-
4.7/
-
7.0

2.1/1.7

14.0/20.7

ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

19

V0 Ligth collection test

For 1 MIP:



Setup A:


light yield: 12 p.e. ;
time resolution (

⤺‱.6 湳



Setup B


Light yield: 33 p.e.; time resolution(

⤺ 1.2


ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

20

V0 Triggering


LVL 0 triggering with fast
electronics
(25 ns)


Dynamic range: 1
-

300 MIP’s


1 MIP efficiency > 97%


Three trigger signals to the
CTP corresponding to 3 sum
energy levels:


Low:MB for pp and Pb
-
Pb
(low)


High: central and


Medium: semi
-
central Pb
-

Pb

Simulations: AliRoot w/ PYTHIA 6.15 in pp at 7 TeV

L and R single efficiencies: 85%

L*R : 79%

Eff. of Inelastic component: 100%

HIJING in Pb
-
Pb at 5.5 ATeV (to be explored)

ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

21

V0 Timetable


Construction

in
2004/2005



V0L by Mexico



V0R by Lyon



Electronics by Lyon


Final system Commissionning




middle 2005




Ongoing work


Light optimization


geometry of the
counter/fiber elements with
beam
tests
-
>

end 2002 (
OK)



Electronics specification ongoing,


PM test and choice in Lyon



Tests of full quadrant w. Beam

-
> end 2003 (delayed from october
2002)



ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

22

T0 Beam
-
Beam counter


Precise event timing

(

=
50灳p


Start detector

for ALICE
-
TOF


Main
LVL0 event trigger


Pre
-
trigger

for TRD


Rough
on
-
line vertex

determination <1.5 cm


Beam
-
gas

suppression



Output Signals:


T0 = (t
r
+t
l
)/2+t
d


T0v = t
r
-
t
l


T0
-
L, T0
-
R, Coinc


Time and energies


3 levels of sum energy (low,
medium, high)



ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

23

T0 Full scale model

ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

24

T0 elements and beam
test


PM tubes: fine mesh


Hamamatsu R3432
-
01 (26 mm
Ø) or FEU
-
187 (30 mm Ø)


30 mm thick radiator (Lucite)



Time resolution with broad
1.28GeV/c pion beam
measured to 55ps.



Set threshold at 200 photons


(1 MIP gives 600 Photons)





Photons in T0
-
R

Photons in T0
-
L

ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

25

T0 efficiency


ALIROOT and Pythia
simulations for MB p+p


200 photon threshold applied


Coinc. eff (L*R) = 83%


Left array:

=71 慮搠a7 %


Right array:

=78 慮搠94 %




T0
-
R * T0
-
L

T0
-
R

T0
-
L

94%

87%

83%

ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

26

T0 timetable


R&D of Cerenkov detector units

-
HV divider


2 prototypes ready,


3
rd

under const. (OK)

-
Quartz radiators


waiting for


final dimensions (no concern)


R&D of fast electronics unit

-
R&D trigger generation unit (CAMAC


prototype ready)

-
prototype I of CFD (failed, high


cross
-
talk but problem solved)

-
prototype II of CFD (ready, very good


test results)

-
prototype III of CFD (ready, very good


test results)

-
prototype IV of CFD (DTD) (theo.stud.)

-
time meaner (2 options) (1 prototype
ready)


Responsibilities: Jyvæskylæ, MEPhI, INR, Budker, Kurchatov.


R&D: laser calibration system


Market survey and purchase
(manufacturer located but the
purchase is delayed to assure the best
configuration)


Development of the calibration
system (still in study)


R&D: DAQ and trigger electronics


Collaboration with TOF to guarantee
the required performance (TOF is only
sub
-
detector requiring high
-
precision
off
-
line T0)


Athens has expressed the wish to
join. Funding situation should be clear
within a few months.


Mechanical construction


1:1 prototype


ready


TDR



progressing as planned

ALICE Si
-
FMD,T0,V0

25/11 2002

Jens Jørgen Gaardhøje, NBI, gardhoje@nbi.dk

27

Summary


FWD detectors baseline defined


Physics role defined


FWD detectors will supply basic
day 1 physics (LVL0 trigger,
global reaction information)


Main detector parameters
specified


Concrete prototyping and
industrial bids started


Projects on track


Aim at TDR by mid
-
2002




Main open issues: integration and
installation procedures, materials
budget (bgd)
, cooling, Back End
Electronics and DAQ integration,
analysis software

Si
-
FMD

T0

V0