CMS Frascati
L.Benussi, M.Bertani, S.Bianco, A.Brotzu,M.A.Caponero,
S.Colafranceschi, D.Colonna , D.Donisi, F.L.Fabbri, F.Felli, M.Giardoni,
T.Greco, B.Ortenzi, M.Pallotta, A.Paolozzi, L.Passamonti, D.Pierluigi,
A.Russo, B.Ponzio,
C.Pucci,
1
12-07-2007
S.Bianco CMS Frascati
- Incontro G.Saviano
Referee
Attivita` 2007 CMS Frascati
1.
Sviluppo e realizzazione del Gas Gain Monitoring System
S.Bianco on behalf of the CMS RPC
Collaboration, “The gas gain monitoring system for the CMS RPC detector”, IEEE06, San Diego (USA)
http://arxiv.org/pdf/physics/0701014.
Sistema di 12 RPC 50cm x 50cm per il monitoring con cosmici delle variazioni del punto
di lavoro dovute alle variazione nella composizione del gas e alla presenza di
contaminanti. In un unico telescopio tre sottosistemi alimentati da fresh Mix, prePurifiers, post-Purifiers
•
Il sistema e` funzionante ed in corso di commissioning a Frascati
•
Scrittura di programmi xDAQ e, successivamente, PVSS iniziata (S.Colafranceschi)
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La gas room @ SX5 non sara’ pronta prima di settembre 2007 --> installiamo il
sistema al Closed Loop dell’ISR, schedule:
•
24 LUGLIO Inizio installazione elettronica, cavi, PC, derivazione gas etc
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3 SETTEMBRE trasporto sistema al CERN, installazione, inizio commissioning
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31 DICEMBRE (milestone) sistema operativo al CERN
Studi del Closed Loop e test all’ISR M.Abbrescia et al., Proposal for a detailed study of Closed Loop…
•
2.
Frascati Preprint LNF 06/27 (IR) available at http://www.lnf.infn.it/sis/preprint/
Iniziata una campagna di studio del Closed Loop con prelievi sistematici di materiale dei
filtri e di gas, e analisi chimiche a largo spettro. Risultati mostrano che le procedure di
rigenerazione vanno capite meglio, e che va studiato il possibile rilascio di elementi dai
filtri.
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In preparazione nuova serie di analisi chimiche piu` mirate
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Test del Closed Loop attualmente operativo con poche camere di vecchia produzione,
nuove gaps attese a fine settembre.
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Person power: laureando Frascati (luglio-agosto-settembre) + summer student.
Installazione e commissioning, shifts
Studi di ageing delle RPC
•
3.
4.
12-07-2007
S.Bianco CMS Frascati - Incontro Referee
2
Gas Gain Monitor (conceptual design)
VENT
RPC TRIG1
RPC TRIG2
Slow Ctrl
GC, p/T/RH/Ph
MONITOR
C2H2F4/SF6 /i-C4H10 /H2O
PURIFIERS
RPC PAD MON1
RPC PAD MON2
RPC PAD MON3
12-07-2007
VENT
VENT
RPC PAD MON4
RPC PAD MON5
RPC PAD MON6
USC5
CMS
REFERENCE
SGX Bldg
UXC5
half wheel lines
RPC PAD REF1
RPC PAD REF2
VENT
RPC TRIG3
RPC TRIG4
VENT
S.Bianco CMS Frascati - Incontro Referee
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Gas gain monitoring chambers
Monitoring della purezza del gas attraverso il controllo
del punto di lavoro di 12 piccole gaps 50cm x 50cm, doppio pad readout
@ GT
STREAMER
12-07-2007
AVALANCHE
-200
knee
CMS RPC preliminary
@ Frascati, test in ambiente
umidita` controllata
S.Bianco CMS Frascati - Incontro Referee
4
Closed loop Studies Summary
• Closed loop filters determined in 2001 at GIF by
looking at GC peaks
• Purifiers in CMS will need daily regeneration, optimize
purifier materials is a must
• Rigorous sampling of purifiers performed:
– New materials
– Used materials
– Regenerated materials
• A broad-spectrum analysis campaign (reference) to
single out problems and to design more focussed
analyses.
• Test ongoing now at ISR with 20 Double-gap RPC’s to
characterize purifiers
12-07-2007
S.Bianco CMS Frascati - Incontro Referee
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La rigenerazione non rimuove S e F dai filtri
S F trend in Ni-Al Filter
S no flux
0.2
F fluxF regener
S flux
0.05
S flux
S regenr
S regenr
0.1
S no flux
%
0.15
F no flux
S IR regener
S Ir flux
F regener
0
Ni-Al
12-07-2007
F flux
Ni Al filter
S.Bianco CMS Frascati - Incontro Referee
S IR no flux
S Ir flux
S IR regener
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Elementi in traccia nelle bacheliti
Il gas riduce la presenza di metalli
sulle bacheliti
Trace Elements Trend (Oiled)
140
120
ppm
100
Cu
80
Ni
60
As
Br
40
Cr
20
Sb
0
0
1
2
3
1(No Flux) 2 (Flux)
12-07-2007
S.Bianco CMS Frascati - Incontro Referee
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Andamento di Cu Zn Pb Ni nelle
zeoliti
La rigenerazione non rimuove i
metalli dalle zeoliti
Zeolite trend pollutants
35
ppm
30
25
Cu
20
15
Ni
10
5
Zn
Pb
0
0
1
2
3
4
1(Unused) 2(fluxed)3(Regenerated)
12-07-2007
S.Bianco CMS Frascati - Incontro Referee
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MOF-B richieste 2008
Le richieste si riferiscono al sistema di gas gain monitoring descritto in [1], e alle analisi per lo studio sistematico
di filtri e gas del Closed Loop
(rif.[2]) attualmente in corso all'ISR e vengono meglio dettagliate come segue:
1) ANALISI CHIMICHE ................ 6.0kEURO
Analisi chimiche (INAA, Fluorescenza, ICP-MS) da effettuarsi esternamente a completamento della prima fase di
caratterizzazione dei filtri [2]. Materiali di consumo e reagenti per il completamento dello studio delle
caratteristiche dei filtri dopo il filtraggio e le operazioni di rigenerazione degli stessi da effettuarsi a cura del
gruppo di Frascati.
2) POOL AFFITTO ELETTRONICA GAS GAIN MONITORING ........ 8.0kEURO
Elettronica di HV, LV, preamplificazione e logica di trigger per le camere del gas gain monitoring. Si propone di
mantenere nel 2008 il sistema finanziato a Frascati ed utilizzare affitto di materiale per il sistema al CERN.
3) SPARE PER GAS GAIN MONITORING ................. 7.0kEURO
Acquisto di n.15 gaps 50cm*50cm come spare delle n.12 camere del gas gain monitoring. Gli spare saranno
realizzati nei primi mesi del 2008, approfittando delle ultime possibilita di produzione prima della chiusura
degli impianti della General Tecnica. Il costo e` lo stesso sostenuto per l acquisto delle n.12 camere del
sistema attualmente in uso.
•
BIBLIOGRAFIA
[1] M.Abbrescia et al., The Gas Gain monitoring system of CMS RPC, http://arxiv.org/pdf/physics/0701014
[2] M.Abbrescia et al., Proposal for a Systematic Study of the CERN Closed Loop Gas System Used by the RPC Muon Detectors in CMS,
Frascati preprint LNF - 06 / 27(IR).
12-07-2007
S.Bianco CMS Frascati - Incontro Referee
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Papers 2006-2007
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Preprints and Conferences
–
–
–
–
–
–
–
S.Bianco on behalf of the CMS RPC Collaboration, “The gas gain monitoring system
for the CMS RPC detector”, IEEE06, San Diego (USA)
http://arxiv.org/pdf/physics/0701014.
C.Pucci “CMS RPC gas gain system”, Annual Congress of Italian Physical Society,
Torino 2006
D.Colonna “Use of FBG sensors for high precision silicon detectors”, Annual
Congress of Italian Physical Society, Torino 2006
M.Abbrescia et al., Proposal for a detailed study of Closed Loop… Frascati Preprint
LNF 06/27 (IR) available at http://www.lnf.infn.it/sis/preprint/
M.Caponero et al., “On the use of FBG sensors in CMS” Siena conference on adv.
Detectors Nov 2006 (to appear on NIM)
A.Paolozzi et al., “Performances of FBG sensors for application at LHC experiments”,
Vienna conference Feb 2007 (to appear on NIM)
S.Bianco et al., Omega-Like Fiber Bragg Grating Sensors as Position Monitoring
Device: A Possible Pixel Position Detector in CMS? Frascati preprint LNF06/13(NT)
Masters and PhD Theses
•
•
•
C.Pucci Analisi dei materiali nelle RPC di CMS Frascati preprint LNF - 06 /
31(Thesis)
D.Colonna Applicazione dei sensori FBG in HEP e nelle strutture Marzo 2007
12-07-2007
S.Bianco CMS Frascati - Incontro Referee
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CMS Frascati Activity in 2008
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•
•
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Commissioning, data taking
Commissioning of gas gain monitoring
Study of closed loop at ISR
Physics studies: Channels with muon pairs (from J/psi,
Upsilon(4s), Z0), profiting of knowledge of RPC and DT
muon detectors
–
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Spectroscopy of Bc-->J/psi , B--> 
Primi pensieri su S-LHC (gems, thin gap rpc, etc)
12-07-2007
S.Bianco CMS Frascati - Incontro Referee
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CMS Frascati 2008
Ricercatori & Tecnologi
Bertani 20%, Bianco 80% Caponero 50%, Colafranceschi 100%
Donisi 100%, Fabbri 70%, Felli 100%,
Giardoni 60%, Pallotta 30%, Paolozzi 30%,
Piga 100%, Pucci 100%, Saviano 100%
TOT=9.4 FTE
Tecnici
Ortenzi 100%, Passamonti 20%
Collaborano: B.Ponzio D.Pierluigi, A.Russo
Laureandi
Greci
12-07-2007
S.Bianco CMS Frascati - Incontro Referee
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SPARE SLIDES
12-07-2007
S.Bianco CMS Frascati - Incontro Referee
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SEM-EDS STUDY OF
IRRADIATED RPCs
We opened RPCs irradiated at the GIF and observed defects on the inner
surfaces.
Anode
Cathode
SEM image of a defect with two magnifications
We performed SEM-EDS and XRD analyses on- and
off-defect…
12-07-2007
S.Bianco CMS Frascati - Incontro Referee
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CLOSED LOOP GAS
RECIRCULATION
Purifiers are THE crucial component
12-07-2007
S.Bianco CMS Frascati - Incontro Referee
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GAS STUDIES
• Resistive Plate Chambers (RPC) detectors are widely used in HEP
experiments for muon detection and triggering at high-energy, highluminosity hadron colliders, in astroparticle physics experiments for the
detection of extended air showers, as well as in medical and imaging
applications.
• While gain and efficiency stability are always a must, in the case of RPC
detectors in high-rate experiments which use freon-based gas mixtures,
utmost care has to be paid also for the possible presence of gas
contaminants.
•The RPC detector of experiment CMS at the LHC proton collider (CERN,
Switzerland) will employ a gas analysis and monitoring system for the online
monitor of the freon-based gas mixture used.
• The gas monitoring system is based on small RPC detectors whose
working point (gain and efficiency) is continuously monitored online. The gas
monitoring system is designed to provide fast and accurate determination of
any shift in working point conditions.
• Quantitative gas chemical analysis is then performed online by a complete
system which includes gas-chromatography, pH sensors and contaminants
(notably HF) detectors.
12-07-2007
S.Bianco CMS Frascati - Incontro Referee
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SEM / EDS analysis of defects inside
irradiated RPC
F peak
Reference bakelite
Off-defect
On-defect
On-defect
Peaks of defects
Na peak
Peaks of NaF
12-07-2007
S.Bianco CMS Frascati - Incontro Referee
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CERN Closed Loop Gas System
• We proposed to study presence of contaminants
and their type of accumulation in the Closed
Loop Gas system (same for CMS and ATLAS)
• Current values in ISR Test Chambers decrease
as the gas circulation changes from a closed to
an open loop
• We are coordinating a three-phase study of CL
– Phase 1 September 06 - study contemporaneous to
chamber testing. Limited by current values.
– Phase 2 March 07 - Dedicated testing of DG’s and
SG’s
– Phase 3 ? - Dedicated testing at GIF possibly synergy
with ATLAS
12-07-2007
S.Bianco CMS Frascati - Incontro Referee
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CERN Closed Loop Gas system
• All system components should be
characterized:
–
–
–
–
Bakelite (all different types of bakelite)
Zeolite (all different zeolite filters)
Other filters based on Cu and Zn and oxides
Gas
by means of a systematic sampling of the
different parts during all of the system work
phases
12-07-2007
S.Bianco CMS Frascati - Incontro Referee
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Phase 1: ISR sampling
September 2006
• Samples (unused, contaminated, regenerated)
have been collected:
– Purifiers:
• Zeolite
• Ni Al2O3;
• Cu, Cu Zn
– Pipes Cu
– Neither oiled nor used bakelite
– Unused bakelite oiled with graphite
12-07-2007
S.Bianco CMS Frascati - Incontro Referee
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Table of analyses
12-07-2007
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Zeolites characterization now used in CL
•
•
•
•
•
•
Different zeolite filters have been
used : 3A, 5A.
They differ in their grain size
dimensions, framework pores
amplitude and chemical
composition
4A (4 Å, Na)
3A (3 Å, K)
5A (5 Å, Ca)
Grain size distribution has been
performed on zeolite filters :
3Å (25 gr)
1,4 mm (8 gr)
1 mm (17 gr)
5Å (25 gr)
2,8 mm (16 gr) 2 mm (9 gr)
12-07-2007
S.Bianco CMS Frascati - Incontro Referee
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Type A zeolites
• Framework of Linde
Type A zeolites
• 4A (4 Å, Na)
• 3A (3 Å, K)
• 5A (5 Å, Ca)
12-07-2007
S.Bianco CMS Frascati - Incontro Referee
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Linde Type A zeolite
(Na96(H2O)216[Si96Al96O384]
REFERENCE
XRD performed at University of Rome “La Sapienza” on a sample of unused zeolite. On the right, the
reference pattern for standard Linde Type A zeolite.
12-07-2007
S.Bianco CMS Frascati - Incontro Referee
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RACKS LAYOUT IN SGX5
Only gas, no electronics
12
1 and 1/2 racks
For gas gain monitor
12-07-2007
Gas quality here +
piping,valves,GC ?
11
MinimizeS.Bianco
signal
cables lengths
CMS Frascati - Incontro Referee
Lateral access
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Integration of Gas Gain Monitoring gaps with
the CERN gas system
12-07-2007
S.Bianco CMS Frascati - Incontro Referee
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GAIN MONITORING SYSTEM
Foam
12-07-2007
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GAS GAIN MONITORING - DOUBLE PAD
Pads 45x45cm2 positive and negative
READOUT
Cosmic ray event
triggered by
scintillation
counters
hodoscope
Sum pulse
12-07-2007
DEVELOPING DIFFERENTIAL AMPLIFICATION SCHEME
TO REDUCE COHERENT NOISE
S.Bianco CMS Frascati - Incontro Referee
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Our FEE options under test
1/6
Several amplification schemes are being explored. Even a simple passive
sum of positive and negative pads and feeding to standard LRS612AM ampli
improves the S/N ratio.
Type A0 - LM6172 - Dual High Speed, Low Power, Low Distortion Voltage Feedback Amplifiers
Gain Bandwidth 100 MHz
Slew Rate 3000 Volts/usec
SupplyCurrent Per Channel 2.3 mA
Supply Min 5.5 Volt
Supply Max 36 Volt
TRASFORMATORI (Zero centrale)
Tipo A
Ferrite Diametro 30mm spessore 6mm
Type A1 - Max 435 Differential, High Speed Op Amp
Gain Bandwidth 275 MHz
Tipo B
Ferrite Diametro 30mm spessore 12mm
Slew Rate 800 Volts/usec
Tipo C
SupplyCurrent Per Channel 18 mA
Miniatura diametro 6mm spessore 3mm
Supply Min 5 Volt
Pad +
Supply Max 12 Volt
Out
Type A2 - LMH6550 Differential, High Speed Op Amp
Pad -
Gain Bandwidth 400 MHz
Slew Rate 3000 Volts/usec
SupplyCurrent Per Channel 20 mA
Supply Min 5 Volt
Supply Max 12 Volt
12-07-2007
S.Bianco CMS Frascati - Incontro Referee
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AMPLI Option
Filtro
PassaBanda
100KHz –
80MHz
Pad +
Oscilloscopio
Lecroy / Tektronix
Pad -
CMS RPC preliminary
10pF
10nF
12-07-2007
<- PEDESTAL
HV=9700V
100uH
4uH
S.Bianco CMS Frascati - Incontro Referee
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