Transcript November 17th, ‘99 Charged Kaons

s
d
n n
K   
+
E. Iacopini, CSN1 Napoli 20 Sett. 2005

• Stato della Collaborazione
(A. Ceccucci)
• Disegno dell’apparato sperimentale
(N. Doble, L. Gatignon)
• Stato della simulazione
(G. Ruggiero)
• Dove siamo con i detectors
• Proposal submitted to SPSC on
June 11, 2005:
“We propose to measure the very rare decay
K+  + 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
Recent developments in the
rare kaon decay community
• A few months ago the Fermilab Directorate endorsed the PAC
recommendation not to pursue K+  + nn at the Main Injector
The physics of K+  + 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  0 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
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)
– Bolotov’s 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)
Endorsement of P326 R&D
by SPSC
• From the draft minutes of the July 05
meeting:
"The SPSC considers it important that
an R&D programme continues
concerned with the possibility of an
experiment to measure the rare
decay K++ n n"
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
From Medium Term Plan, CERN/2615
Legend:
Approved
Under Consideration
2004 2005 2006 2007 2008 2009 2010
LHC Experiments
PS and SPS Shutdown
•Will determine the future course of high energy physics
•Detector completion/upgrade/in particular for luminosity upgrade ( 1035)
(~2014); requires R&D, machine and detectors
ALICE
ATLAS
CMS
LHCb
TOTEM
Other LHC Experiments
(e.g. MOEDAL, LHCf)
Non-LHC Experimental Programme
•Very limited neutrino programme (in scope)
SPS
COMPASS
•New initiatives include K++nn; why not K00nn..?
NA48
NA60
Neutrino / CNGS
New initiatives
•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)
OTHER
FACILITIES
EURISOL
Design to
Study
(including
beta
beams)
•New
initiatives
appear
in Budget
Plan
from 2006 (or maybe 2007)
AD
ISOLDE
onwards
n-TOF Neutron
CAST
DIRAC
Test Beams
•Accelerator R&D includes EU funded networks, joint projects, design
studies
North Areas
West
Areas
•Linear colliders: Eurotev
(‘generic’)
and CLIC (CERN and partners,
No fully-fledged NeutrinoEast
Factory
Design
Study yet (2008 if EU support)
Hall
‘collaboration’, feasibility proof
by 2009)
R&D
(Detector & Accelerator)
Slides from Niels Doble & Lau Gatignon
13
12
+
K decays in 50 m
12
11
/ 3 10
10
+
inc. p
+
K / 
6
x10
9
-2
x 10
8
7
6
Choice of
K+
momentum:
K+ / Total beam
-2
x 10
5
-3
(for 400 GeV/c proton momentum)
4
x 10
3
x 10
+
-14
+
K decays in 50 m
/ Total beam
+
K flux
12
/ 3 10 inc.p)
Acceptance
2
8
x 10
1
-1
x 10
0
40
50

Acc. K to  nn
/ Total beam
60
70
+
80
90 100 110 120 130 140 150
K momentum [GeV/c]
(2 RMS)
1.5
K+
+
n
n
800 MHz
(/K/p)
10 MHz Kaon
decays
Solo i rivelatori upstream sono esposti
a 800 MHz di fascio (8.6% K) …
Thanks to Giuseppe Ruggiero
Background kinematically
constrained
Decay
BR
Km2
0.634
+0
0.211
++- (00)
0.070
92% of total background
+0 forces us to split the signal region
Background not kinematically
constrained
Decay
Ke3
Km3
Km2g
+0g
Ke4
Km4
BR
0.049
0.033
5.5×10-3
1.5×10-3
4×10-5
1×10-5
8% of total background
Spoils the signal region
Background rejection
Goal of P326: S/B ≈ 10
~10-12 rejection
2-steps background rejection:
1) Kinematical rejection
Region I: 0 < m2miss < 0.01 GeV2/c4
Against Km2, +0
Region II: 0.026 < m2miss < 0.068 GeV2/c4
Against +0, ++-, +00
2) Veto and Particle ID
g, m, charged particles
m –  - e separation
Sources of background
Kinematical rejection inefficiency
Resolution effects
Non gaussian tails
Beam pile – up
Simulated using Flyo
Simulated using GEANT4
Simulated using Flyo
Veto and particle ID inefficiency
RICH
m – veto
g – veto
Simulation (Jurgen)
Simulation (Oleg)
Parameterization (Simulation in progress by Rome)
(Data in progress: LKr by NA48/2, ANTI by Frascati)
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(P)/P = 0.23% + 0.005% P (GeV/c)
s(qK) = 60 – 20 mrad (P = 10 – 50 GeV/c)
+0 m2miss resolution
qK
qK
q
Ptrack
PK
Veto and particle ID
g – Veto:
RICH (Simulation by
Jurgen):
g inefficiency parameterization
17 m long, 1.0 atm Ne
JURGEN
E range
Inefficiency
< 50 MeV
1
ANTI (0.5, 1) GeV
LKR

m – Veto (Geant4 simulation
by Oleg):
hm-veto = 10-5
IRCs
SAC
10-4
> 1 GeV
10-5
< 1 GeV
1
(1,3) GeV
10-4
(3,5) GeV
10-4 - 10-5
> 5 GeV
10-5
All
10-6
Some general remarks …
Kaon Flux: 4.8×1012 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
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 < Rtrack < 85 cm (centered on the hole of the chamber)
RICH: 12 cm < Rtrack < 120 cm (both on front and back surfaces)
LKr: Octagonal outer shape and Rtrack > 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)
Selection (2)
Fiducial decay region
5 m < Zvertex < 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 < Ptrack < 35 GeV/c
Specific cuts
DPtrack/Ptrack < 2.5×s(P)/P (against the not gaussian tails)
CDA < 0.8 cm (against the tails from the beam pile – up)
Kinematics
REGION I: 0 < m2miss < 0.01 GeV2/c4
REGION II: 0.026 < m2miss < 0.068 GeV2/c4

m
n
Acceptance after all the cuts: Acc=(8 ± 2) × 10-6
Same procedure as for +0 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: <0.1 / year
Nngaus ~ 0.4 / year, Npileup ~ 0.8 / year
+0
Acceptance after all the cuts: Acc = (1.3 ± 0.1) × 10-4
Assumption: independence between kinematical rejection inefficiency
(hkin) and selection acceptance
NI,II = hkin×Nsel(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(0) = 2 × 10-8
Expected events:
N(+0) = Fkaon × BR × Acc × h(0) = (2.7 ± 0.2) / year
–
–
–
Region I: 1.7 / year
Region II: 1.0 / year
Nngaus ~ 0.5 / year, Npileup ~ 2.2 / year
Two body background vs
Spibes performances
2 body background events
2 body background events
Total
Total
+0
Km2
s(t) Spibes ns
+0
Km2
h Spibes ineff
Other backgrounds
Ke3:
Acceptance ~12% (Flyo)
h0 ~ 3×10-8
Positron ID: hLKr × hRICH < 10-3 × 10-3 (conservative)
NEGLIGIBLE
Km3:
Acceptance ~17% (Flyo)
h0 ~ 3×10-8
Muon ID: hRICH × hMAMUD < 10-5 × 10-2 (conservative)
NEGLIGIBLE
+00:
High suppression from kinematics and g veto
NEGLIGIBLE
Signal Acceptance
Selection applied on nn 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(+nn)=8×10-11 (SM)
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 < Zvertex < 65 m
Most important cuts
Ntrack=1:
cuts 8% of events
Geometry: cuts 10% of events
Momentum: cuts 50% of events
Pile – Up: cuts 12% of events
Signal and backgrounds / year
Signal
+0
Km2
Ke4
++- and 3-tracks
+0g
Km2g
Ke3, Km3
Total bkg
Total
~65
2.7±0.2
1.2±0.3
2±2
1±1
1.3±0.4
0.4±0.1
negligible
9±3
Region I
~16
1.7±0.2
1.1±0.3
negligible
negligible
negligible
0.2±0.1
Region II
~49
1.0±0.1
<0.1
2±2
1±1
1.3±0.4
0.2±0.1
3.0±0.2
6±3
Tentative sharing of construction
responsibility (sept. 05)
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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 (CERN+INFN)
MAMUD (INR+Protvino)
SAC + IRC (Sofia)
Trigger & DAQ (CERN+INFN+?)
A. Ceccucci August 31 2005 - Cambridge
Abbiamo, molto schematicamente, due problemi:
• Politico:
la Collaborazione ha bisogno di rinforzarsi.
Ci sono stati notevoli passi in avanti nel 2005, come discusso
all’inizio, e comunque noi continueremo su questa strada …
• Tecnico:
siamo in grado di installare i rivelatori che ci servono?
Per questo abbiamo un programma di R&D per tutti i nuovi rivelatori
e per validare quanto resta dei vecchi (il LKr …)
Il 27 settembre, verrà presentata all’SPSC, insieme alla
Proposta P326, una contestuale richiesta di 30 gg di run per
il 2006, sulla solita linea di fascio K12, principalmente per
- misurare l’inefficienza di osservazione dei fotoni con il LKr
- misurare il fondo da /K interagenti con il gas residuo
- determinare l'alone del fascio
- effettuare i tests necessari sui prototipi dei nuovi rivelatori
(Cedar, hodo, sensori gigatracker …)
R&D
sui rivelatori
di nostra pertinenza:
Hodoscopio
Veto dei g
Gigatracker
FI-PG
L’idea è quella di usare Glass Multigap RPCs, sullo stile di
quanto realizzato in ALICE
A questo rivelatore infatti è richiesto di essere efficiente
(>99%) e di avere un’ottima risoluzione temporale (50ps)
in modo da ridurre al massimo la possibilità di associazioni
accidentali fra il pione di decadimento ed il K che lo origina.
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
 5+5 250 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
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 Ω) 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).
The NINO ASIC
bonded to the PCB
On each front end card 3 NINO chip are mounted so the card can
handle 24 channels
MRPC performance
Efficiency > 99%
Time resol. < 50 ps
Test performed with the
ALICE TOF rate 50 Hz
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
Ageing test at GIF
Irradiation with 7∙109 particles/cm2
The performances seem to remain stable in
time
 The total amount of irradiated charge is
equivalent to only 140 days of P326 run:
7  109
1

 P326RUN ( days)
2
rate / cm * 86400 duty - cycle
G MRPC for P326
Signal electrode
Cathode -10 kV
(-8 kV)
(-6 kV)
(-4 kV)
(-2 kV)
Anode 0 V
Signal electrode
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
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
– It’is 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
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.
•
Must achieve inefficiency < 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,
FWHM~70 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
•
Large angle vetoes
The detector must be able to veto
0s, 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 punchthrough, inefficiency dependence from
the hitting angle, energy and position,
… are concerned.
But also to be compared
Costs
Mechanical design of the support …
LNF, NA,
PI, RM1
Tile and KLOE geometry
1 cm
1 mm
30 cm
2/16
29.9 cm
2.5 m
1 cm
42.5 cm
Beam Axis
Aluminum
Lead
Scintillator
1 mm
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
@ 1.2 Gev/c 3*10-6
In 2006 we would like to
arrange in Frascati a
comparative test with it
and a KLOE prototype, to
be built.
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..
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.
13
Setup
11
8
10
5
12
7
2
9
4
6
1
3
0
H finger
V finger
Vista Y
• VME DAQ
• Charge integrating ADC, gate=200 ns
• trigger dal sistema di timing del fascio
Vista X
Fascio ottimizzato: sx  sy  2 mm
Bassa intensità: <n>=0.5 ÷1
Inefficienza (preliminare !)
Eventi
CAVEAT
Tutti
Con tag
• Prototipo realizzato nel
1992, e strumentato su
un solo lato
Etotale
• Qualche canale mostra
un guadagno più basso
(accoppiamento ottico
guida/fotomoltiplicatore?)
Inefficienza
• I canali non erano
equalizzati né calibrati
(run di cosmici in corso…)
 11000 eventi con tag
• La Statistica é limitata …
e l’analisi é ancora in corso
(ADC)
70
140
210
280
350
Soglia
(MeV)
Piano di lavoro 2006
Test alla BTF con elettroni e fotoni (quando disponibili):
• Misura dell’inefficienza 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
In particolare,
vorremmo poter
confrontare i risultati
– Ottimizzazione
dell’elettronica
diottenuti
readout
sul prototipo “CKM” e “Protvino” con quelli avuti su un
prototipo
“a la KLOE” da costruire.
– Ottimizzazione
del guadagno
… in modo che, entro il 2006 si possa giungere alla
scelta della tecnologia
Premessa:
FE-TO
(CERN)
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
R/O chip
Sensore
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  n nbar non si avra' alcuna informazione
sulla posizione del vertice di decadimento (solo il + viene rivelato).
Le informazioni dal Gigatracker dovranno permettere la coincidenza
di un + 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 <0.4%,
Dq ~17mrad
mantenendo minimo il materiale posto su fascio (X0<<1%).
12.32m
fascio
rate ~1GHz
maggior parte
, solo 6.5% K
final collimator,
decay volume,
detector
6.05m
40mm
Pixel2
86.731m
from T0
Pixel 1
80.681m
from T0
Kabes
99.051 m
from T0
87m
Ch1
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 /√12 -> sX= 58 (87) mm,
MultSc Si spessore 200mm~13mrad
 sxMSP1= 13*6.05 ~80mm
V pixel size  mom resol (P1,P2) ( sX√2 & sxMSP1 )/40mm
 200mm (300) = 0.3% (0.4%)
H pixel size  Angular resol(P2,K3 skab=80mm)
(sX & skab ) /12.3m & sMSP1
 200mm (300) = 15mrad (16mrad)
≈35000 canali/stazione
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€…)
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)
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
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
@ Scuola LNL 4-8/04/2005
Dove siamo?
3 wafer (200mm-ex300A/B, 200ex600B) sent @ VTT
for bb with Alice's chip
--> expected back at CERN soon
Example of n-type inversion on 300mm thick
test structures for Alice, R.Wundstorfs thesis
Alice's standard test on the Ladder
Diodes and pixel arrays: tests and dicing
---> Legnaro for
irradiation studies with protons (bulk damage)
- measure Vfd, Ileak vs fluence and
- find equivalent fluence inversion point
- monitoring vs time and temperature
p+
n
n+
Toward the working point in P326...
- Feq inversion point and Vbias --> replacement every xxx days?
- cooling (e.g. ATLAS, CMS ~ -8°C : Ileak)
69
Programma 2006:
Sensor:
Test on
Chip:
- Alice-like ladders and singles bb at VTT
R&D ongoing
- diodes & structures dicing
simulation & design
●
--> Legnaro, monitoring
●
Investigation on wafer bow: causes and
how to reduce it
first hints if 0.25mm not possible
expected by January06
(dimensions, consumption...)
If OK --> 2006 build and test
a chip with the various
functional blocks and
Cooling:
architecture options
investigation just started
70