A1258689907tNxJr

1
P326
E. Iacopini, CSN1 Napoli 20 Sett. 2005
2
Abstract

• Stato della Collaborazione
• (A. Ceccucci)
• Disegno dellapparato sperimentale
• (N. Doble, L. Gatignon)
• Stato della simulazione
• (G. Ruggiero)
• Dove siamo con i detectors

3

• Proposal submitted to SPSC on
• June 11, 2005
• We propose to measure the very rare decay K ?
  p nn at the CERN SPS to make a decisive test of
  the Standard Model by extracting a 10
  measurement of the CKM parameter Vtd.
• The open presentation to the SPSC is scheduled on
  September 27, 2005

4
Recent developments in the rare kaon decay
community

• A few months ago the Fermilab Directorate
  endorsed the PAC recommendation not to pursue K
  ? p nn at the Main Injector
• The physics of K ? p nn was considered very
  important but a potential conflict for protons
  between the kaon and the neutrino possible
  programmes at Fermilab lead to this
  recommendation
• Very Recently the RSVP program was terminated
• The m to e conversion experiment (MECO) and the
  K0 ? p0 nn experiment, ready to start
  construction at BNL, will not be built
• This leaves CERN and Japan (JPARC) as the only
  places where an ultra-rare kaon decay experiments
  are currently envisaged
• However, to be completely fair, one should also
  mention
• Plans at Protvino as mentioned at KAON2005
• Plans at Frascati to study KS at an upgraded phi
  factory

5
Strengthening P326

• The demise of the US kaon program has triggered
  negotiations with members of KOPIO/CKM to join
  P326
• The following groups have signed up since the
  proposal submission
• S Louis Potosi (Mexico, J. Engelfried)
• Bolotovs group (Moscow, INR)
• Interest to join has been expressed by the
  following groups
• Fermilab (P. Cooper)
• BNL (L. Littenberg)
• British Columbia (D. Bryman)
• However, a possible participation of US groups is
  subject to
• DOE support towards a strong contribution to the
  construction of the detector (notably the RICH
  counter)
• The involvement of US Universities in addition to
  National Labs (at least for BNL)

6
Endorsement of P326 RD by SPSC

• From the draft minutes of the July 05 meeting
• "The SPSC considers it important that an RD
  programme continues concerned with the
  possibility of an experiment to measure the rare
  decay K?p n n"

7
CERN Program and Plans introduction to Round
Table discussion on The Future of High Energy
Physics ECFA-EPS Joint Session at HEPP-EPS
2005 International Europhysics Conference on High
Energy Physics Lisbon, July 21 -27, 2005
Jos Engelen CERN
8
From Medium Term Plan, CERN/2615

• Will determine the future course of high energy
  physics
• Detector completion/upgrade/in particular for
  luminosity upgrade (? 1035)
• (2014) requires RD, machine and detectors

• Very limited neutrino programme (in scope)
• New initiatives include K???? why not
  K0??0??..?
• New initiatives may include a long term neutrino
  programme
• CERN working groups Proton Accelerators for the
  Future (PAF)
• and Physics Opportunities at Future Proton
  Accelerators (POFPA)
• New initiatives to appear in Budget Plan from
  2006 (or maybe 2007)
• onwards

EURISOL Design Study (including beta beams)

• Accelerator RD includes EU funded networks,
  joint projects, design
• studies
• Linear colliders Eurotev (generic) and CLIC
  (CERN and partners,
• collaboration, feasibility proof by 2009)

No fully-fledged Neutrino Factory Design Study
yet (2008 if EU support)
9
P326 oggi
Slides from Niels Doble Lau Gatignon
10
Choice of K momentum
(for 400 GeV/c proton momentum)
11
(2 RMS)
12
(No Transcript)
13
Il Detector
1.5
p
K
n
n
800 MHz (p/K/p)
10 MHz Kaon decays
Solo i rivelatori upstream sono esposti a 800 MHz
di fascio (8.6 K)
14
(No Transcript)
15
(No Transcript)
16
Il RICH ...
17
(No Transcript)
18
La simulazione MC del fondo e del segnale
Thanks to Giuseppe Ruggiero
19
Background kinematically constrained
Decay BR
Km2 0.634
pp0 0.211
ppp- (p0p0) 0.070
92 of total background
pp0 forces us to split the signal region
20
Background not kinematically constrained
Decay BR
Ke3 0.049
Km3 0.033
Km2g 5.510-3
pp0g 1.510-3
Ke4 410-5
Km4 110-5
Spoils the signal region
8 of total background
21
Background rejection

• Goal of P326 S/B 10 10-12
  rejection
• 2-steps background rejection
• 1) Kinematical rejection
• Region I 0 lt m2miss lt 0.01 GeV2/c4
• Against Km2, pp0
• Region II 0.026 lt m2miss lt 0.068 GeV2/c4
• Against pp0, ppp-, pp0p0
• 2) Veto and Particle ID
• g, m, charged particles
• m p - e separation

22
Sources of background

• Kinematical rejection inefficiency
• Resolution effects
• Non gaussian tails
• Beam pile up
• Veto and particle ID inefficiency
• RICH
• m veto
• g veto

Simulated using Flyo Simulated using
GEANT4 Simulated using Flyo
Simulation (Jurgen) Simulation (Oleg) Parameteriza
tion (Simulation in progress by Rome) (Data in
progress LKr by NA48/2, ANTI by Frascati)
23
Resolutions (Flyo MC)

• Gigatracker
• 300 x 300 mm pixels
• 0.4 X0 per Spibes
• Simple reconstruction
• 2 inefficiency per station
• Double Spectrometer
• 80mm resolution in X and Y hits (125 mm per view)
• 0.5 X0 per chamber
• Track momentum from fit
• Angle from first 2 chambers
• Fully efficient

• Results
• s(PK)/PK 4.2 x 10-3
• s(qK) 16.7 mrad
• s(Pp)/Pp 0.23 0.005 Pp (GeV/c)
• s(qpK) 60 20 mrad (Pp 10 50 GeV/c)

pp0 m2miss resolution
qpK
qK
qp
PK
Ptrack
24
Not gaussian tails (GEANT4)
pp0 30-35 GeV/c

• Simulation
• Toy simulation of the Double Spectrometer, based
  on GEANT4
• Interactions
• Electromagnetic, Hadronic
• Reconstruction
• Average material 0.5 X0 (no straws geometry)
• d-ray production allowed
• No digitization, coordinates smeared with
  gaussians
• Effects
• Tails in the reconstructed momentum and angle
  smearing of the m2miss
• Spoiling of the rejection power for the
  kinematical constrained background

• Approximation
• Non gaussian effects in the Gigatracker not
  taken into account

25
Beam pile-up (Flyo)

• Simulation
• Accidental track superimposed in Gigatracker to
  the kaon track
• Accidental track generated according to the beam
  momentum bite, dimension and divergence
• Rate 800 MHz
• SPIBES time resolution 200 ps, inefficiency 2
  
• HODOSCOPE time resolution 80 ps

• Effect
• The downstream track can be matched with the
  wrong track danger expecially for p p0

• Analysis
• Only upstream tracks within 500 ps from the
  downstream track are considered good upstream
  tracks 32 of events have gt1 good track in Giga
• Track choice based on c2 from DT and CDA
• About 1.7 of events matches the wrong track

26
Veto and particle ID

• RICH (Simulation by Jurgen)
• 17 m long, 1.0 atm Ne
• m Veto (Geant4 simulation by Oleg)
• hm-veto 10-5

• g Veto
• g inefficiency parameterization

E range Inefficiency
ANTI lt 50 MeV 1
ANTI (0.5, 1) GeV 10-4
ANTI gt 1 GeV 10-5
LKR lt 1 GeV 1
LKR (1,3) GeV 10-4
LKR (3,5) GeV 10-4 - 10-5
LKR gt 5 GeV 10-5
IRCsSAC All 10-6
JURGEN
27
Some general remarks

• Kaon Flux 4.81012 decay/year in the fiducial
  region
• Detector Layout as described in the proposal
• Straw chambers 5cm inner radius displaced in x,
  according to the positive beam deflection in the
  spectrometers
• Magnets of the double spectrometer
• MNP33 1 Ptkick 270 MeV/c
• MNP33 - 2 Ptkick -360 MeV/c
• All the expected background given per 1 year of
  data taking

28
Selection (1)

• Number of tracks
• 1 positive downstream track (hit in all the 6
  chambers)
• Choice of the upstream track using minimum c2
  (Dt, cda)

• Detector geometry
• Downstream track inside of the detector
  acceptance
• Straws 10 cm lt Rtrack lt 85 cm (centered on the
  hole of the chamber)
• RICH 12 cm lt Rtrack lt 120 cm (both on front and
  back surfaces)
• LKr Octagonal outer shape and Rtrack gt 15 cm
• MAMUD square shape, 260x260 cm outer, 36x30 cm
  inner (front and back)

• Particle ID
• Not muons in RICH or MAMUD
• Not electrons in RICH or LKr (LKr with 10-3
  inefficiency of e ID)

29
Selection (2)

• Fiducial decay region
• 5 m lt Zvertex lt 65 m (from the final collimator,
  Zvertex defined as the Z coordinate of the point
  closest to both the tracks)

• Cut on momentum
• 15 GeV/c lt Ptrack lt 35 GeV/c

• Specific cuts
• DPtrack/Ptrack lt 2.5s(P)/P (against the not
  gaussian tails)
• CDA lt 0.8 cm (against the tails from the beam
  pile up)

• Kinematics
• REGION I 0 lt m2miss lt 0.01 GeV2/c4
• REGION II 0.026 lt m2miss lt 0.068 GeV2/c4

30
m n

• Acceptance after all the cuts Acc(8 2) 10-6
• Same procedure as for pp0 to extract the
  acceptance

• Muon veto inefficiency
• hMAMUD (m) 10-5 (MAMUD)
• hRICH (m) 5 10-3 (RICH) (conservative)
• Assumption MAMUD and RICH rejection
  inefficiencies independent

• Expected events
• N(Km2) Fkaon BR Acc hRich (m) hMAMUD
  (m) (1.2 0.3) / year
• Region I 1.1 / year
• Region II lt0.1 / year
• Nngaus 0.4 / year, Npileup 0.8 / year

31
pp0

• Acceptance after all the cuts Acc (1.3 0.1)
  10-4
• Assumption independence between kinematical
  rejection inefficiency (hkin) and selection
  acceptance
• NI,II hkinNsel(Flyo)Npileup(Flyo)
• NI,II Number of expected events in regions I
  and II after all the cuts
• Nsel(Flyo) number of events selected in Flyo
  before the cut on m2miss
• Npileup(Flyo) number of events in Regions I and
  II due to the beam pileup
• Acc NI,II / Ngen(Flyo)

• Photon veto inefficiency
• h(p0) 2 10-8

• Expected events
• N(pp0) Fkaon BR Acc h(p0) (2.7 0.2)
  / year
• Region I 1.7 / year
• Region II 1.0 / year
• Nngaus 0.5 / year, Npileup 2.2 / year

32
Two body background vs Spibes performances
2 body background events
2 body background events
Total
Total
pp0
pp0
Km2
Km2
h Spibes ineff
s(t) Spibes ns
33
Other backgrounds

• Ke3
• Acceptance 12 (Flyo)
• hp0 310-8
• Positron ID hLKr hRICH lt 10-3 10-3
  (conservative)
• NEGLIGIBLE
• Km3
• Acceptance 17 (Flyo)
• hp0 310-8
• Muon ID hRICH hMAMUD lt 10-5 10-2
  (conservative)
• NEGLIGIBLE
• pp0p0
• High suppression from kinematics and g veto
• NEGLIGIBLE

34
Signal Acceptance

• Selection applied on pnn events generated with FF
  (from CMC)
• Effects not taken into account
• Random veto
• Accidental loss due to hit multiplicity cuts
• Straw inefficiency
• Loss due to cuts in MAMUD for muon ID
• BR(pnn)810-11 (SM)

35
Signal Acceptance

• Results
• REGION I (4.10 0.03) 10-2
• REGION II (12.88 0.05) 10-2
• Total (16.98 0.06) 10-2
• Acceptance normalized in the region 5 m lt
  Zvertex lt 65 m

• Most important cuts
• Ntrack1 cuts 8 of events
• Geometry cuts 10 of events
• Momentum cuts 50 of events
• Pile Up cuts 12 of events

36
Signal and backgrounds / year
Total Region I Region II
Signal 65 16 49
pp0 2.70.2 1.70.2 1.00.1
Km2 1.20.3 1.10.3 lt0.1
Ke4 22 negligible 22
ppp- and 3-tracks 11 negligible 11
pp0g 1.30.4 negligible 1.30.4
Km2g 0.40.1 0.20.1 0.20.1
Ke3, Km3 negligible - -
Total bkg 93 3.00.2 63
37
Results S/B

• S/B (Total) 7.6 2.0
• S/B (Region I) 5.2 1.1
• S/B (Region II) 8.9 3.6
• Some S/B dependence on detector parameters

uncorrelated errors
Hodo time resolution
Spibes time resolution
Spibes inefficiency
80 ps
200 ps
2
38
Responsabilità
39
Tentative sharing of construction responsibility
(sept. 05)

• Beam Line (CERN)
• CEDAR (CERN)
• GIGATRACKER (CERN, INFN, Saclay kabes)
• VACUUM TANK (Common fund)
• ANTI Counters (INFN)
• STRAW TRACKER (DUBNA, MAINZ)
• MNP33/2 (Common Fund)
• CHOD (INFN)
• RICH (US? Mexico)
• LKR (CERNINFN)
• MAMUD (INRProtvino)
• SAC IRC (Sofia)
• Trigger DAQ (CERNINFN?)

A. Ceccucci August 31 2005 - Cambridge
40
... Una stima dei costi
Element Cost (MCHF) Comments
BEAM LINE 0.4 Modified K12 line
CEDAR 0.5 Replacement of photon detectors
GIGATRACKER 2.7 (1.4) Assuming 0.13 mm CMOS technology
VACUUM 1.0 Addition of 20 large diffusion pumps
ANTI 4.2 (4.2) CKM estimate 40 for the electronics
STRAW TRACKER 2.4 6 straw chambers
MNP33/2 2.5 (1170 prolongation of He tank)
CHOD 0.9 (0.9) MGG-RPC
LKR 2.0 !!! New supervision system and R/O
RICH 4.0 Indication
MAMUD 1.5 Cost of iron 0.5 MCHF
SAC, IRC1 IRC2 0.4 Shashlik or PbWO4
Trigger DAQ 1.5 (0.7) L0 HW, L1 SW
TOTAL 24.0 (7.2)
41
Il contributo INFN prevedibile per la costruzione
dei sottorivelatori
Gigatracker 0.7-1.0 M (assumendo 50
sharing) Anticounters 2.8-3.4 M Chod
0.50.7 M Trigger 0.5-0.8 M
(assumendo 40 sharing) TOTALE
4.5-5.9 M
(Nella proposta sono quotati 7.2 MCHF 4.8 M )
42
Come contiamo di procedere ...

• Abbiamo, molto schematicamente, due problemi
• Politico
• la Collaborazione ha bisogno di rinforzarsi.
• Ci sono stati notevoli passi in avanti nel 2005,
  come discusso
• allinizio, e comunque noi continueremo su questa
  strada
• Tecnico
• siamo in grado di installare i rivelatori che ci
  servono?
• Per questo abbiamo un programma di RD per tutti
  i nuovi rivelatori
• e per validare quanto resta dei vecchi (il LKr )

43
RD 2006 Il Run ...
Il 27 settembre, verrà presentata allSPSC,
insieme alla Proposta P326, una contestuale
richiesta di 30 gg di run per il 2006, sulla
solita linea di fascio K12, principalmente
per  - misurare linefficienza di osservazione
dei fotoni con il LKr  - misurare il fondo da
p/K interagenti con il gas residuo  -
determinare l'alone del fascio  - effettuare i
tests necessari sui prototipi dei nuovi
rivelatori (Cedar, hodo, sensori gigatracker
)
44
RD sui rivelatori di nostra pertinenza Hodosc
opio Veto dei g Gigatracker
45
The fast hodoscope
FI-PG
Lidea è quella di usare Glass Multigap RPCs,
sullo stile di quanto realizzato in ALICE A
questo rivelatore infatti è richiesto di essere
efficiente (gt99) e di avere unottima
risoluzione temporale (50ps) in modo da ridurre
al massimo la possibilità di associazioni accident
ali fra il pione di decadimento ed il K che lo
origina.
46
ALICE detector layout

• 13x120 cm2 area for each module
• 7x120 cm2 active area for each module

• 2 anode and 1 chatode PCB with picup pads
• 55 250 mm gaps filled with gas mixture
• 1 cm honeycombs panel for mechanical stability
• 96 pads per module readout with 32 flat cable
• Differential signal send to interface card

• Greater number of gaps
• Lower HV (6.5 kV, -6.5 kV)
• Signal amplitude greater of a factor 2

47
Front-End electronics
ALICE has developed for this purpose, fast (1ns
peaking time) front-end amplifier/discriminator
(NINO). Each NINO can handle 8 channels. The
input is low impedance (40-75 ?) differential,
and the output standard is an open-collector
LVDS (Low Voltage Differential Signal). NINO
can respond to another signal immediately (few
ns) after the end of a previous signal (almost no
dead time). On each front end card 3 NINO chip
are mounted so the card can handle 24 channels
The NINO ASIC bonded to the PCB
48
MRPC performance
Efficiency gt 99Time resol. lt 50 ps
Test performed with the ALICE TOF rate 50 Hz
49
Rate tests at GIF

• The MRPC were tested for efficiency up to a rate
  of 1.6 kHz
• The performance seem to be stable only using an
  effective voltage of 11.4 kV

• The MRPC were tested for time resolution up to
  a rate of 1.6 kHz
• The time resolution seem to decrease a little
  bit
• The resolution at 1.6 kHz is well above 100 ps
• This performance are very suitable for P326

• New high rate test are mandatory to validate
  performance up to 5 kHz

50
Ageing test at GIF

• The performances seem to remain stable in time
• The total amount of irradiated charge is
  equivalent to only 140 days of P326 run

51
G MRPC for P326
We stick as much as we can to the Alice design,
however to reduce material, we are planning a
single stack layer. The time resolution,
according to experts, should go from 40 ps to
80 ps
52
The new PCB for P326

• The PCB design used by ALICE is not suitable for
  P326
• The connectors on each side introduce too much
  dead space between two modules
• Itis very difficult to bring signals out of the
  detector using ALICE configuration
• The material budget would not be uniform due to
  connectors and cables
• We are working on a new PCB layout, assuming
• Connectors only at the end of each module
• Each module is single-layer

53
Where we are

• First prototype assembly foreseen in late
  november
• Cosmic ray test will be done, hopefully,
  within 2005
• Test of efficiency and time resolution at high
  rate
• are mandatory to validate the possible use of
  such a
• detector in P326
• test envisaged with NA48 test-run facility in
  2006.
• We are now investigating the possibility of
• performing the rate test, using some existing
  ALICE
• modules at some beam facility, to be found.

54
The gamma veto
55

• Must achieve inefficiency lt 10-5 to detect
  photons above 1 GeV, and this
• has to be tested in 2006.
• It has also to be evaluated the effect on the
  inefficiency of the material in front of the
  calorimeter (RICH, hodoscope, windows, etc)
• Advantages
• It exists
• Homogeneous (not sampling) ionization calorimeter
• Very good granularity (2 ?2 cm2)
• Fast read-out (Initial current, FWHM70 ns)
• Very good energy (1, time 300ps and position
  (1 mm) resolution
• Disadvantages
• 0.5 X0 of passive material in front of active
  LKR
• The cryogenic control system needs to be updated
• Needs a new readout

Il LKr ...
56
Large angle vetoes
LNF, NA, PI, RM1

• The detector must be able to veto p0s, with
  energy in the range
• 40-65 GeV, at the 10-8 level.
• This means that it must possess an average
  veto power on the single photon of the order 10-4
  

Two technologies are to be compared Tiles a
la CKM Spaghetti a la KLOE Extensive
Geant4 simulation started to study both solutions
as far as punch-through, inefficiency dependence
from the hitting angle, energy and position,
are concerned. But also to be compared Costs Mech
anical design of the support
57
Tile and KLOE geometry
1 cm
1 mm
29.9 cm
58
The CKM prototype at FNAL
Former CKM physicists interested in joining
us. A lot of R/D was already done for CKM
vetoes. A prototype (2 sectors, 80 layers,
1mm/5mm) exists at FNAL, tested in an electron
beam. Results are published Inefficiency for
electrons _at_ 1.2 Gev/c 310-6 In 2006 we would
like to arrange in Frascati a comparative test
with it and a KLOE prototype, to be built.
59
The Protvino prototype

• Protvino has the know-how for scintillator
  production
• They have bought all the manufacturing equipment
  for scintillator from Uniplast (in Vladimir)
• Extruded scintillator
• Molded scintillator
• Intended to be used for CKM (Kplus) and KOPIO
• Interested to collaborate.
• A 20 layer prototype already available,
• Full prototype under consideration
• Opportunity to use this facility for P326
• Need discussion, inspection, agreement, control,
  etc..

60
Test con elettroni del prototipo KLOE già
iniziati

• Presa dati con Elettroni da 480 MeV, alla BTF
  dei LNF, dal 18 al 22 luglio, in modalità
  parassita alle normali operazioni per KLOE.

61
Setup

• VME DAQ
• Charge integrating ADC, gate200 ns
• trigger dal sistema di timing del fascio

Fascio ottimizzato sx ? sy ? 2 mm Bassa
intensità ltngt0.5 1
62
Inefficienza (preliminare !)

• CAVEAT
• Prototipo realizzato nel 1992, e strumentato su
  
• un solo lato
• Qualche canale mostra un guadagno più basso
  (accoppiamento ottico guida/fotomoltiplicatore?)
• I canali non erano equalizzati né calibrati (run
  di cosmici in corso)
• La Statistica é limitata
• e lanalisi é ancora in corso

63
Piano di lavoro 2006

• Test alla BTF con elettroni e fotoni (quando
  disponibili)
• Misura dellinefficienza in funzione di
• Energia
• Posizione/angolo di impatto (studio degli effetti
  di bordo)
• Misura della risoluzione temporale
• Misura della risoluzione in energia
• Studio dei segnali
• Ottimizzazione dellelettronica di readout
• Ottimizzazione del guadagno

In particolare, vorremmo poter confrontare i
risultati ottenuti sul prototipo CKM e
Protvino con quelli avuti su un prototipo a
la KLOE da costruire. in modo che, entro il
2006 si possa giungere alla scelta della
tecnologia
64
FE-TO (CERN)
Gigatracker
Premessa Il Gigatracker consta di 2
stazioni di Pixel posizionate nella regione del
secondo achromat, dove il fascio viene deviato di
-40mm in direzione verticale e riportato in
posizione dopo circa 6 metri. Le due
stazioni di pixel dovranno misurare la posizione
e il tempo di passaggio delle particelle del
fascio. Dalla seconda
stazione e da una terza, equipaggiata con una
FastTPC (KABES), ci si attende la misura della
direzione di tali particelle, minimizzando la
deviazione dovuta al multiple scattering.
Bump bonding
65
Caratteristiche
La dimensione del fascio alle stazioni di pixel
e' di circa 36x48mm2, con un rate massimo di
1.9MHz/mm2, 0.6MHz/mm2 in media, e in totale
circa 1 GHz, di cui solo circa il 6 sono K.
Dal decadimento del K in p n nbar non si
avra' alcuna informazione sulla posizione del
vertice di decadimento (solo il p viene
rivelato). Le informazioni dal Gigatracker
dovranno permettere la coincidenza di un p visto
nel rivelatore (tempo dal hodo e direzione e
momento dallo spettrometro) con un K passato nel
GT. Questo impone ai pixel
risoluzioni, sia spaziali che temporali,
piuttosto stringenti, tali da avere, sulla
traccia
Dt 150ps,
Dp/p lt0.4, Dq 17mrad
mantenendo minimo il materiale posto su fascio
(X0ltlt1).
66
86.731m from T0
99.051 m from T0
80.681m from T0
204.850m from T0
- Ottimizzazione spessore 300mm Si 100
(chip) 200 (rivelatore)
150 (chip) 150 (rivelatore)
supporto segnale! Da
testare segnale, fragilita', danneggiamento
da radiazione
(12 Mrad in 100 gg)
- Ottimizzazione dimensioni pixel sX 200
(300) mm /v12 -gt sX 58 (87) mm, MultSc Si
spessore 200mm13mrad ? sxMSP1 136.05
80mm V pixel size ? mom resol (P1,P2) (
sXv2 sxMSP1 )/40mm
? 200mm (300) 0.3 (0.4)

H pixel size
? Angular resol(P2,K3 skab80mm)
(sX skab ) /12.3m sMSP1

? 200mm (300) 15mrad (16mrad)
35000 canali/stazione
67
R/O chip

• Per la realizzazione dell'elettronica di
  lettura dei rivelatori a pixel si stanno
  studiando due opzioni tecnologiche
• la CMOS 0.25 mm e la CMOS 0.13 mm.
• La tecnologia 0.25 mm è ben conosciuta e
  caratterizzata nei suoi aspetti di prestazioni
  analogiche e di radiation tolerance ed i costi
  sono relativamente contenuti.
• Di contro le prestazioni che offre sono
  nettamente inferiori e queste potrebbero non
  essere sufficienti per l'esperimento.
• Inoltre il supporto e l'aggiornamento del
  design kit per il progetto di circuiti
  tolleranti alle radiazioni si e inoltre
  interrotto nel 2002.
• La 0.13 mm è attualmente in fase di
  caratterizzazione per quanto
• riguarda sia le prestazioni analogiche che
  la tolleranza alle radiazioni.
• Trattandosi poi di una tecnologia di punta
  i costi saranno superiori di un
• fattore 2 rispetto alla 0.25 mm (2 M
  invece di 1 M)

68
E per il sensore, da dove si parte?

• Le richieste di P326 sul sensore al Si sono
• spessore 200mm (min X0)
• pixel dim 300mm x 300mm OK
• (risoluzione su P e q)

Convenzione INFN-ITC/IRST cfr delibere
8610,8649 Lavorazione gratuita solo spese
materiale es maschere, sensori Non solo
business... anche ricerca e su vari substrati
(n,p-type) di varia produzione (epi, FZ,
CZ...) cfr es Boscardin _at_ Scuola LNL 4-8/04/2005

• Esperienza Alice SPD
• Sensore Si CANBERRA
• high resistivity FZ
• p pixel su substrato n
• spessore 200mm
• pixel size 50mmx425mm
• r/o chip CMOS 250nm
• spessore Si supporto 150mm
• (nativo 750mm)
• bump bonding SnPb VTT Finlandia best of the
  best
• yield 99

Test produzione lavorazione bb VTT al chip di
Alice con aggiunta strutture test ad hoc Vincoli
layout chip Alice
69
Dove siamo?
3 wafer (200mm-ex300A/B, 200ex600B) sent _at_ VTT
for bb with Alice's chip --gt expected back at
CERN soon Alice's standard test on the
Ladder Diodes and pixel arrays tests and dicing
---gt Legnaro for irradiation studies
with protons (bulk damage) - measure Vfd,
Ileak vs fluence and - find equivalent
fluence inversion point -
monitoring vs time and temperature
Example of n-type inversion on 300mm thick test
structures for Alice, R.Wundstorfs thesis
p n n
Toward the working point in P326... - Feq
inversion point and Vbias --gt replacement every
xxx days? - cooling (e.g. ATLAS, CMS -8C
Ileak)
69
70
Programma 2006

• Sensor
• Test on
• - Alice-like ladders and singles bb at VTT
• - diodes structures dicing
• --gt Legnaro, monitoring
• Investigation on wafer bow causes and
• how to reduce it
• Cooling
• investigation just started

Chip RD ongoing simulation design first
hints if 0.25mm not possible expected by
January06 (dimensions, consumption...) If OK --gt
2006 build and test a chip with the
various functional blocks and
architecture options
70