Stato dell’esperimento MEG
•Stato dell’esperimento (LXe, T.C., Trigger a
parte)
• Schedule
• Budget
• MoU
• Richieste finanziarie
A. Baldini 23 sett
CSN I Lecce
1
Detector overview
“espulsione” dei positroni
FWHM resolutions
• Liquid Xe e.m. calorimeter
• Magnetic spectrometer
• Timing counter
A. Baldini 23 sett
CSN I Lecce

 ( Eγ , pγ / Eγ , t γ )

 pe

 ( pe / Ee , te )
2
Ee
E
 γ
 eγ
t
 eγ
 4 π
0.7  0.9%
4%
17  20.5 mrad
150 ps
9%
La collaborazione
INFN & Genova University S. Dussoni, F. Gatti, P. Ottonello, D. Pergolesi, R.
Valle
INFN & Lecce University S. Spagnolo, C. Chiri, P. Creti, G. Palama’, M. Panareo
INFN & Pavia University A.de Bari, P. Cattaneo, G. Cecchet, G. Nardo’, M.
Rossella
INFN & Pisa University A. Baldini, C. Bemporad, F.Cei, M.Grassi, F. Morsani,
D. Nicolo’, R. Pazzi, F. Raffaelli, F. Sergiampietri, G. Signorelli
INFN Roma I D. Zanello
ICEPP, University of Tokyo T. Mashimo, S. Mihara, T. Mitsuhashi, T. Mori, H.
Nishiguchi, W. Ootani, K. Ozone, T. Saeki, R. Sawada, S. Yamashita
KEK, Tsukuba T. Haruyama, A. Maki, Y. Makida, A. Yamamoto, K. Yoshimura
Osaka University Y. Kuno
Waseda University T. Doke, J. Kikuchi, H. Okada, S. Suzuki, K. Terasawa, M.
Yamashita, T. Yoshimura
PSI, Villigen J. Egger, P. Kettle, H. Molte, S. Ritt
Budker Institute, Novosibirsk L.M. Barkov, A.A. Grebenuk, D.G. Grigoriev, B,
Khazin, N.M. Ryskulov
A. Baldini 23 sett
CSN I Lecce
3
Magnet: Construction finished!
• Construction was finished!
• Excitation test has started on June.
Superconducting coil in cryostat
Potentiometer
A. Baldini 23 sett
Support frame
CSN I Lecce
4
Compensation coils
Jan 2002:
COBRA Magnet schedule
2002
Design
Winding & Cryo.
2003
Ass.
2004
2005
Test
Platform
Deliv.
Test
PSI
Field
Measurement
Jan A.
2003:
Baldini 23 sett
CSN I Lecce
Design
Manufactoring
5
Assembly
Test
Milestone
Platform design status (June 24th)
A. Baldini 23 sett
CSN I Lecce
6
Area Layout
Trigger & DAQ
optional wall
electronics
HV
small rail
LXe
storage
A. Baldini 23 sett
CSN I Lecce
compressor
7
“Z-Branch” Measurements April/May2003
Measurements:
Phase B – post Triplet 2 & Collimator
Phase C – post Solenoid
Several unexpected problems encountered & Solved !!!
A. Baldini 23 sett
CSN I Lecce
8
Phase C Post Solenoid
Trip.
µ++
e
1
WIEN
Colli.
Triplet 2
µ+
Solenoid
e+
Filter
Remember !!! PSC only a Test Solenoid
PSC-Solenoid 20cm Bore
Beam Line 32 cm Bore
Single Node SNM
Integrated Rate
After Solenoid
4cm Tg.E @ 1800µA
Nµ~6.1·107 µ+/s
(1.1·108 µ+/s 6cm Tg.)
Beam Spot:
Double Node DNM
Previous Excitation
Curve DNM confirmed
DNM focus Z0 14.53 A
Previous U-Branch
14.56 A
A. Baldini 23 sett
CSN I Lecce
σX ~ 5.3 mm
σY~ 6.5 mm
Transmission Factor
Solenoid
TSol= 71 %
With larger Bore i.e. BTS T>71%
9
Degrader & Stopping Distribution Measurements
Target Thickness vs. NaI Rate
Michel Range Curve using NaI:
e+
Foils CH2
at focus
µ+
Solenoid
AIR
VAC
CH2 Tg
Fix Degrader
Var. Tg
R ~ 870 µ CH2
Degrader
Target
Target
88% stopped
in 400µ CH2 Tg.
Measurement  Simulation
Fix Degrader 600 µ Geant say 580µ
Nearly all Stopped in 400µ
A. Baldini 23 sett
CSN I Lecce
Gives RMean = 1150µ
Equiv GEANT + TRIM
88% STOP in 400µ Tg !!!
10
Beam
Jan 2002
2002
2003
2004
2005
Studies
Quadrupoles
Solenoid
Target
Jan A.
2003:
Baldini 23 sett
CSN I Lecce
Design
Manufactoring
11
Assembly
Test
Milestone
Drift chambers
•Prototypes of cathodes supporting structure
•Print foils meeting the experimental requirements found
•Tests at M1: drift time measurements and cathodes readout
•First studies on pattern recognition (Pisa + Lecce)
A. Baldini 23 sett
CSN I Lecce
12
Example of reconstructed tracks
A. Baldini 23 sett
CSN I Lecce
13
Algorithm performances
Michel positrons in the solid angle covered by the spectrometer
or isotropically over the whole detector; no significant
differences; positron momentum > 30 MeV;
# of correctly reconstructed tracks
Efficiency = ———————————————
# of generated tracks
Mixing
Mean number of
Efficiency on
Efficiency on
mixed tracks
first turn
second turn
1
5
5
10
10
98.2
95
95.8
91
92.1
98.5
98.4
98.1
97.5
97.5
None
Poisson
Fixed
Poisson
Fixed
A. Baldini 23 sett
CSN I Lecce
14
Jan 2002:
Positron Tracker
2002
2003
2004
2005
Medium Prototype Charge division & Cosmics
Full Prototype
FP
FP
Full Detector (18 DC)
A. Baldini 23 sett
CSN I Lecce
Design
Manufactoring
15
Assembly
Test
Milestone
Timing Counter
Jan 2002:
2002
2003
2004
PMT Evaluation
2005
PMT
Design
•Tests of fine mesh PMTs (even in
magnetic fields) and of counter
prototypes (M1) going on
•Good solution for transverse detector:
scintillating fibers + APDs
A. Baldini 23 sett
CSN I Lecce
Design
Manufactoring
16
Assembly
Test
Milestone
Photon Detector schedule
2002
Large Prototype
2003
Beam Test
2004
Beam Test
2005
Engineering runs
Vessel Design
Manufactoring
PMT Delivery + Testing
Refrigerator
Manufactoring
Assembly & Test
Assembly
Test
Assembly
Liq. Purification
A. Baldini 23 sett
CSN I Lecce
Design
Manufactoring
17
Assembly
Test
Milestone
Electronics
•Need of at least two prototypes (both for the trigger and the
DRS)
•First trigger prototype is being tested
•Second DRS design is being designed
A. Baldini 23 sett
CSN I Lecce
18
Trigger
Jan 2002
2002
2003
2004
2005
Prototype Board
2nd Prototype
Full System
A. Baldini 23 sett
CSN I Lecce
Design
Manufactoring
19
Assembly
Test
Milestone
DRS (DAQ)
Jan 2002
2002
1st Prototype
2003
2004
2005
Tests
2nd Prototype
Boards & Chip
A. Baldini 23 sett
CSN I Lecce
Design
Manufactoring
20
Assembly
Test
Test
Milestone
Jan 2002:
Complete Detector
2002
2003
2004
2005
Platform
Engineering
Runs
Detector
Integration
•Start of the experiment in 2006
•All possible engineering runs in 2005
A. Baldini 23 sett
CSN I Lecce
Design
Manufactoring
21
Assembly
Test
Milestone
Calorimeter PMT
Lxe
Vessel
Various items
Xe system
Cobra Magnet
1756
845
400
271
369
1175
Timing counter
Trigger
700
400
Drift Chambers
Muon transport
DAQ Electronics
Detector
HV
149
184
405
172
39
Budget (K€)
6865
Japan
Italy
PSI
2529
2200
1299
Approved in april
Approved in may
MoU
6028
Running costs - 2008
1303
2003-2005
Deficit per 350 PMT
A. Baldini 23 sett
CSN I Lecce
22
Stime di costo aggiornate
LXenon
Trigger
• PMT(300)
550 K€
• Secondo prototipo
20 K€
• Criostato
400 K€
• Sistema completo
430 K€
Timing counter
Splitters
• APD + fibre (interno)
160 K€
• PMT (100: esterno)
315 K€
• Sistema completo
TOTALE
115 K€
2190 K€
• Scintillatore
50 K€
• Calibrazione
100 K€
1095 K€
50 K€
545 K€
675 K€
550 K€
• Meccanica
A. Baldini 23 sett
CSN I Lecce
23
Preventivo globale
A. Baldini 23 sett
CSN I Lecce
24
Preventivo 2004
Tot
38
315
66
Settembre 2003
• PMT LXe
20
261
• APD
80 K€
Prima meta’ 2004
• Scint T.C.
50 K€
• PMT T.C.
• fibre
• Criostato
• Splitters 1
315 K€
80 K€ Seconda meta’ 2004
400 K€ • Trigger 1
50 K€
• Calibr. T.C.
845 K€ • Mecc. T.C.
215 K€
100 K€
65 K€
380 K€
A. Baldini 23 sett
CSN I Lecce
2536
Proposta ...
550 K€
680 K€
1836
25
2005
• Trigger 2
• Splitters 1
215 K€
50 K€
265 K€
Milestones 2004
A. Baldini 23 sett
CSN I Lecce
26