Stato dell

1
Stato dell esperimento MEG

• A - In costruzione
• LXe test PMT, costruzione criostato,
  calibrazioni
• TC
• trigger
• (Beam line, DC, Elettronica)
• Ritardi in alcune parti O(mesi)
• B - Risultati finali dei test dello scorso anno
  ?Stima della sensibilita
• C - Schedule

A.M. Baldini
2
A) Costruzione 1. Calorimetro LXe
Test dei PMT

• Test of ½ of the PMTs for the final experiment
• Three steps
• Measurement of the gain at 800 Volt (ggt106)
• Rate dependence test (linear up to 4 uA)
• QE and timing resolution measurement to classify
  PMTs

3
Test dei PMT

• 130 PMTtested at Pisa (rate of about 3/day)
  (iniziato ad agosto al PSI) a fine luglio

n. di PMT/giorno dominato dalla purezza dello
Xenon
4
Misure di efficienza quantica
QE in f. della purezza (correggibile)
QE per varie misure successive (stabilita)
different Xe purity
rms 3.2
Confronto con la misura nel LP (Ottobre 2004)
5
Confronto con misure Hamamatsu

• We have QE measurements from Hamamatsu for 30
  PMTs, made at 175 nm and room temperature.

175 nm, room temperature
LXe spectrum, -107 C
6
Timing resolution

• The timing resolution of each PMT is measured
  with alpha source
• Quite well reproduced by data

7
Lotto attuale

• 60 110 PMTs
• Visual inspection showed bad gluing of quartz
  window for several PMTs (gt10)
• Will be replaced by Hamamatsu together with
  out-spec.

8
Criostato

• Gara organizzata in quattro parti
• Vessel caldo e freddo
• Finestre sottili
• Guarnizioni fredde
• Supporto PMT

9
Stato attuale

• Criostato e finestre sottili
• SIMIC (CN)
• Materiale a bassa perm. magnetica arrivato
• Non ancora concordata una schedule ! (questa
  settimana definizione)
• Guarnizioni
• Garlock (2 mesi)
• Struttura di supporto
• Galli Morelli (LU) (5/6) (2 mesi)
• Parte frontale in fase di definizione (2 mesi)
• (delrin/peek)

Nuovo ingegnere 100 per MEG !!! Borsa PL...
10
Calibrazioni

• Acceleratore di protoni int. su Li (17.6 MeV ?)
  50 INFN 250 K nella seconda meta di agosto
  il DOE ha garantito il finanziamento a UCI (MECO
  e KOPIO definitivamente affossati)
• Ordine (a fornitore unico) a breve (impegno
  fondi)
• Nuova possibilita per una calibrazione con ??
  conversione di uno dei fotoni in un convertitore
  e misura nelle camere camere a drift

11
2. Timing Counter final desing review
Scintillator Slab ? 20rotation increase response
uniformity and timing performance achievable by
using the coincidences ? Positron Path-Length (5
cm)enough for the required Timing Res. ?
Maximal Matching Scintillator-PM -gt Note cut
of upper edge(5mm in radial direction in order to
avoid TC-D.C. contact -gt lower edge is also
cut away in order to have symmetrical shape ?
Optimal compromise between PM field gain
suppression factor availabe space. PM tilted of
20º respect to the Mag.Field, 10º respect to
the axis
Scintillator Cross Section
5mm
5mm
PM active diameter 39 mm
Sectional view
PM outer Diameter 52 mm
0.75 T
1.05 T
Long. view
12
Re-shaped Scintillating Slab
Curved Scintillating Fiber
Scintillating Slab
Hollow adapter and Slab black cover
13
TC Final Design
A PLASTIC SUPPORT STRUCTURE ARRANGES
THE SCINTILLATOR BARS AS REQUESTED THE BARS
ARE GLUED ONTO THE SUPPORT INTERFACE ELEMENTS
ARE GLUED ONTO THE BARS AND SUPPORT THE FIBRES
FIBRES ARE GLUED AS WELL TEMPORARY ALUMINIUM
BEAMS ARE USED TO HANDLE THE DETECTOR DURING
INSTALLATION PTFE SLIDERS WILL ENSURE A SMOOTH
MOTION ALONG THE RAILS
14
APD comparison PSI(blue), new Hamamatsu (red)
I 50 nA
15
APD read-out final design
16
Final design of N2 bag(Saran He input in the TC
bag few x 10-5 mbar/day)
17
Laser

• Purposes MONITORING of
• timing calibration of longit. TC,
• timing inter-calibration TC-LXe,
• timing resolution of TC (and LXe?)
• Needed High Power picosecond pulse laser at
  350-530 nm
• Single bar test 405nm, 5mW, 100ps laser -gt final
  10.000 ph/pulse
• Loss at fiber injection 0.1, bar acceptance
  0.04, Q.E. PMT 0.15 (total about 6x10-4) -gt ½ W
  laser for 50-100 fibers
• If pulse duration larger than timing resolution,
  in order to reduce first photon spread, needed
  larger power
• HW NdVanadate SS laser 1064nm r.rate0.1MHz,
  frequency converter to 532 or 355,Beam expander,
  fiber injector, 50um fiber.
• PICONOVA (High Q Laser) 1W/8ps
• PICOLAS (ALFALAS) 5W/12ps
• RAPID (LUMERA LASER) 2W/10ps

18
3. Trigger system structure
2 boards
2 VME 6U 1 VME 9U Located on the platform
LXe inner face (216 PMTs)
2 x 48
92 boards
. . .
1 board
LXe lateral faces back (216 PMTs) 4 in 1 lat.
(144x2 PMTs) 4 in 1 up/down (54x2 PMTs) 4 in 1
9 x 48
2 x 48
1 board
2 x 48
Timing counters curved (640 APDs) 8 in 1 u/d
stream (30x2 PMTs)
1 board
2 boards
Drift chambers 1616 channels
2 x 48
19
Ancillary boards
Trigger Event counter Trigger pattern
to DRS
Busy Error
from DAQ
Start Stop
Start Stop Sync CLK
ANCILLARY Mother
. . .
CLK 20 MHz
VME
ANCILLARY Daughters
Acq start Acq end Trigger conf. Sync Res
CLK
to DRS
20
Trigger test

• Test sulla scheda Type1 in corso
• Test sulla scheda Type2 a meta ottobre
• Test del sistema entro fine ottobre
• Lieve ritardo di un mese sulla milestone 2005
• Scheda Ancillary semplice
• Ancillary prototype correttamente funzionante e
  pronto per il test del sistema
• Splitter (Lecce)
• disegno definitivo pronti per la produzione

21
4. AOB Beam line BTS _at_ PSI
Dear colleagues! BTS progress report for
18.07.2005 morning - replace the Helium
transfer line 1100   - the Helium temperature
is achieved, coil is superconducting          
but Helium dewar is empty 1320   - receive full
Helium dewar 1530   - the BTS cryostat is full
1620   - ramp up current up to 30A, the field
in BTS is observed by           deflection of
steel screw, which hangs on wire at cryostat edge
...     - test and adjust quench protection
circuit 2000   - the current of 283 A is
reached The maximal current is limited by power
the supply maximal voltage and the power cable
resistance now. The BTS was tested up to 300 A at
Novosibirsk with another power supply. with
best regards,                     Dima
22
Beam line separatore pronto area sperimentale
sempre piu (piattaforma, COBRA, barracca...)
23
Drift chambers

• Materiale (catodi) ok. In corso la definzione
  delle procedure di costruzione

Elettronica di readout

• DRS in fase di investigazione la dipendenza
  dalla temperatura. DRS3 pronto nel 2006
  sostituira il DRS2

24
Measured timing resolution averge 91 ps FWHM
B) Risultati dei test del 2004
25
Comparison of MEG TC with other timing detectors

• MEG TC 4x4x90 BC404 R5924 270 38

Table form E.Nappi / Bari
26
Timing resolution
p-

• T TDC - Tref
• TDC correction for time-walk and position
• TL, TR by weighted average of Ti
• ltTgt (TL?TR)/2

TL
?ir.m.s. of Ti cut on Qigt 50 pe
Left
Right
g
TR
27
Absolute timing resolution, Time reference (LYSO)
(TLYSO(R) -TLYSO(L))/2
s64 psec
PMT1
PMT2

• LYSO PMT1 2
• Coorected for x-coord. (not for y)
• Corrections applied for time walk (negligible at
  high energy deposit)

with 1cm slit
28
Absolute timing, Xe-LYSO analysis
high gain
normal gain
110 psec
103 psec
55 MeV
s LYSO Beam L-R depth reso.
110 64 61 65 56 33 psec
103 64 61 53 43 31 psec
Normal gain
High gain
O(150 ps FWHM) we had lt230 ps
29
Beam spot on target

• Beam profile
• sH 13.2 mm
• sV 9.9 mm
• (as measured by P. Kettle)
• ?? sp 62.3 ps

30
Fondo e sensibilita
Jan 2004 Jan 2005 Gamma Energy
() 4.5-5.0 e Timing (nsec) 0.1 0.09 Gamm
a Timing lt0.23 0.15 Gamma Position
(mm) 4.5-9.0 Gamma acceptance gt0.4 Muon rate
(108/sec) 0.2-0.3 0.25-0.35 Running Time
(107sec) 4.0 Accidental Rate (10-14) 2.3-3.5 1.9-3
.0 Accidental Events 0.6 0.6 90 CL Limit
(10-13) 1.2-1.7 0.9-1.4
Measured w/ new PMTs
Detailed calculations necessary
31
Xenon Delivery

• Additional grant 656 kCHF
• Last 50l subject to negotiation

575 kCHF granted
1 MCHF
Japan
32
2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005
J J J J F F F F M M M M A A A A M M M M J J J J J J J J A A A A S S S S O O O O N N N N D D D D
Beam Time Shutdown Shutdown Shutdown Shutdown Shutdown Shutdown Shutdown Shutdown Shutdown Shutdown Shutdown Shutdown MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG Gotta Gotta Gotta Gotta Gotta Gotta Gotta Gotta MEG MEG MEG MEG MEG MEG MEG
COBRA Tests Tests Platf. Platf.
Beam Line BTS Tests BTS Tests BTS Tests BTS Tests Comm. Comm. Comm. Comm.
Drift Chamber Proto Inst Proto Inst Proto Inst Proto Inst
Timing Counter Test Test
LPT PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration PMT Test and Calibration
Full Calorimeter Cryogenics Installation Cryogenics Installation Cryogenics Installation Cryogenics Installation Cryogenics Installation Cryogenics Installation Cryogenics Installation Cryogenics Installation
Trigger
DAQ DC Electr. DC Electr. DC Electr. DC Electr. TC Tst TC Tst
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2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006 2006
J J J J F F F F M M M M A A A A M M M M J J J J J J J J A A A A S S S S O O O O N N N N D D D D
Beam Time Shutdown ? Shutdown ? Shutdown ? Shutdown ? Shutdown ? Shutdown ? Shutdown ? Shutdown ? Shutdown ? Shutdown ? Shutdown ? Shutdown ? Shutdown ? Shutdown ? Shutdown ? Shutdown ? MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG MEG
COBRA Field Map Field Map Field Map Field Map
Beam Line
Drift Chamber Full Installation Full Installation Full Installation Full Installation Full Installation Full Installation Full Installation Full Installation
Timing Counter Full Installation Full Installation Full Installation Full Installation Full Installation Full Installation Full Installation Full Installation
LPT
Full Calorimeter Installation Installation Installation Installation Installation Installation Installation Installation Installation Installation Installation Installation
Trigger Inst Inst Inst Inst
DAQ Inst Inst Inst Inst
34
Conclusioni

• Consideriamo LHC come il nostro competitore
• Cercheremo di ottenere risultati significativi
  il prima possibile