1. GAS
S.Bianco Colafranceschi Benussi Piccolo, …
2. SENSORS4UPGRADE
S.Bianco S.Buontempo Caponero Breglio…, …
Stefano Bianco per CMS Frascati
s.bianco (frascati) CMS RPC Italia 12 maggio
1
GAS
Gas review al cern sull’incident della rottura del flussimetro
SF6 (0.30% --> 0.39%) piuttosto produttiva:
https://indico.cern.ch/conferenceDisplay.py?confId=137611
1.
e minute di Pigi
s.bianco (frascati) CMS RPC Italia 12 maggio
2
SF6 Mass Flow Controller – follow-up
15/4
possible problem concerning the RPC gas mixture composition reported
the SF6 mass flow controller (MFC).
MFC changed (19:30) and to start preparing the gas chromatograph (GC).
17/4
17:00 after discussion with RPC group, I put back the old MFC
Analyses results: the old MFC is delivering about 30% more SF6 with respect the new.
SF6
C2H2F4
iC4H10
s.bianco (frascati) CMS RPC Italia 12 maggio
3
SF6 Mass Flow Controller
18/4
20:00 New MFC again in use
19/4
New analysis confirmed the 34% difference between the two MFCs (i.e. 0.4 % instead of 0.3 % of SF6 in the
mixture).
20/4
21:50 SF6 concentration in the return mixture from the detector: 0.325%
old MFC verified on the our Bronkhorst calibration stand: 35% difference in the output flow confirmed.
21/4
12:00 SF6 concentration in the return mixture from the detector: 0.323%
21:00 SF6 concentration in the return mixture from the detector: 0.322%
25/4
21:00 SF6 concentration in the return mixture from the detector: 0.314%
3/5
Old MFC reinstalled after recalibration
21:00 SF6 concentration in the return mixture from the detector: 0.312%
Regular analysis (1-2 per week  Beatrice) will be performed until when the CMS GC will be
fully operational
s.bianco (frascati) CMS RPC Italia 12 maggio
4
GGM on wrong mix problem
The GGM HV scan confirms shift of WP
due to wrong mix
In progress analysis of charge ratios
timeline to spot (wrongMix->goodMix)
transition which should have occurred
delayed in clean and (after/before) gas
mixtures. A small transient effect
possible.
s.bianco (frascati) CMS RPC Italia 12 maggio
5
PRELIMINARY
GGM down :-((((
+-10%
after down
2,500
charge ratio
2,000
1,500
1,000
0,500
0,000
1301000000
-0,500
1301500000
1302000000
1303000000
1302500000
1303500000
1304000000
1304500000
time
APRIL 2011
s.bianco (frascati) CMS RPC Italia 12 maggio
HV scans
6
after down
0.30%-->0.39% SF6
1,500
1,300
charge ratio
1,100
0,900
0,700
0,500
0,300
1302840000
1302940000
1303040000
1303140000
1303240000
1303340000
1303440000
1303540000
time
s.bianco (frascati) CMS RPC Italia 12 maggio
7
after down
14
12
10
adc
8
6
4
2
0
1302840000
1302940000
1303040000
1303140000
1303240000
1303340000
1303440000
1303540000
1303340000
1303440000
1303540000
time
clean down
charge ratio
ADC
20
15
10
5
0
1302840000
1302940000
1303040000
1303140000
1303240000
time
s.bianco (frascati) CMS RPC Italia 12 maggio
8
after down
20
adc
15
10
5
0
1301000000
1301500000
1302000000
1302500000
1303000000
1303500000
1304000000
1304500000
1303500000
1304000000
1304500000
time
charge ratio
ADC
clean down
20
15
10
5
0
1301000000
1301500000
1302000000
1302500000
1303000000
time
s.bianco (frascati) CMS RPC Italia 12 maggio
9
CONCLUSIONS 0/3
1.
2.
Il gas group effettuera’ misure di GC con il
sistema CMS in USC 1/2 volte a settimana
(Beatrice)
Il GC INFN verra’ installato in SGX5 e
operato da RPC
s.bianco (frascati) CMS RPC Italia 12 maggio
10
CONCLUSIONS 1/3
• GGM :
– Stable operation, performance up to specs.
• INFN GC :
– Install and operate in SGX5 gas room
– Issues: automatize & integrate DCS/PVSS
– runs : ~2 days frequency
s.bianco (frascati) CMS RPC Italia 12 maggio
11
CONCLUSIONS 2/3
•The GGM is not designed for detecting overall gas mixture changes
•Studies in progress to verify the feasibility of detecting gas mixture changes
via the transient in the charge ratios. Small effects.
• We propose to widen the scope and performance of GGM in order to
provide an additional mean of monitoring for the RPC gas mixture
• GGM+ :
– HV feedback. Change HV supply to gaps as a function of p and
T. Monitor charge and ratios
•
•
•
•
PVSS changes including PVSS integration… 0.5 month
Unix data analysis… 1.5 month
Commissioning and debugging…….. 0.75 month
Value added: Gain experience for a CMS RPC feedback
– HV scans. Every 10 days
•
•
•
•
PVSS changes …0.5 month
Auto scan tool C++/ROOT … 2.0 months
XDAQ changes… 0.5 month
Commissioning and debugging 0.5 month
• Need 6.5 months support for a Frascati engineer (R.Aurilio or
C.Vendittozzi).
s.bianco (frascati) CMS RPC Italia 12 maggio
12
CONCLUSIONS 3/3
1.
Abbiamo trovato e capito alcuni GGM
analysis bugs
2. Il transiente si vede
3. A Frascati stiamo facendo HVSCAN con
twin GGM
•
SF6 = 0.30/0.39/0.33/0.30/0.25
•
Circa altri 10 giorni
4. A CERN abbiamo iniziato serie di HV scan
con GGM per studiare sistematica e
alternative al fit con la sigmoide
s.bianco (frascati) CMS RPC Italia 12 maggio
13
TASKS & RICHIESTE
1. Install INFN GC and operate in SGX5
•
1 mese … Beatrice (PV) oppure Vendittozzi
(Frascati)
2. GGM+
•
6.5 mesi … Vendittozzi (Frascati) o Aurilio
(Frascati) o ??? Altra risorsa RPC
(Pakistan/India etc)
s.bianco (frascati) CMS RPC Italia 12 maggio
14
POSSIBILE RIORGANIZZAZIONE GAS
•
GAS ()
1.
2.
3.
4.
Gas quality …. GC ()
Gas calibration ….GGM (Frascati)
Liason to gas group (Benussi)
Detector (leak tests + ???) ()
s.bianco (frascati) CMS RPC Italia 12 maggio
15
SENSORS4RPC
Frascati + Napoli
• Installare sensori ottici FBG per temperatura
camere endcaps nuove +esistenti
• 2013 ma vogliamo iniziare a comprare,
certificare, saldare sensori al polipo ASAP
• Oggi distribuito primo draft di specifiche tecniche
gara
• Next: riunioni frascati/napoli
• Lab Frascati pronto per test accettazione, Napoli
anche disponibile
s.bianco (frascati) CMS RPC Italia 12 maggio
16
SPARE SLIDES
s.bianco (frascati) CMS RPC Italia 12 maggio
17
RPC GAS MONITORING
1.
Gas Gain Monitoring (GGM)
•
Monitoring of working point for changes
due to differences among clean, afterpurifiers, before-purifiers gas mixtures.
Monitoring of charge ratios
(afterPurifiers/clean, beforePurifiers/clean)
allows cancellation of p,T,H effects
2. Gas Quality Monitoring
•
Monitoring of chemical composition of gas
mixtures
s.bianco (frascati) CMS RPC Italia 12 maggio
18
RPC GAS SYSTEM AND
MONITORING
Gas quality monitoring
Purifiers
GC+others
(half wheel pickup points)
GC
FpH
other
Mixer
Gas gain monitoring
Humidifier
RPCs #1
Fresh gas
RPCs #2
Before purifiers
CMS
UXC55
USC55
SGX5
s.bianco (frascati) CMS RPC Italia 12 maggio
RPCs #3
After purifiers
DAQ
Performance
detector
monitoring
ENV.
CONTROL
gas parameters
Ambient parameters
19
19
GGM
• Eight single gap RPCs with charge
readout in a cosmics telescope
• Three sets of gaps: clean gas, beforepurifier gas, after-purifier gas.
Cancellation of p,T by ratioing.
• fully integrated in DCS/PVSS
•In operation and shift monitoring since
2009 https://twiki.cern.ch/twiki/bin/view/CMS/RPComm
s.bianco (frascati) CMS RPC Italia 12 maggio
20
GGM

s.bianco (frascati) CMS RPC Italia 12 maggio
21
GGM
s.bianco (frascati) CMS RPC Italia 12 maggio
22
Gas Gain Monitoring Performance
Avalanche Streamer
Anode charge in avalanchestreamer
transition region monitors shifts in
working point.
SENSITIVITY ~ 20V
0% SF6
+-3%rms
Coherent effects cancel out due to system
redundancy. The two-gap ratio cancels out
0.3% SF6
s.bianco (frascati) CMS RPC Italia 12 maggio
LONG-TERM ENVIRONMENTAL
EFFECTS
AT THE +-3% LEVEL
23
GGM on PVSS
s.bianco (frascati) CMS RPC Italia 12 maggio
24
GGM TWIN IN FRASCATI CMS LAB
T,H controlled hut
Gaschromatograph
DAQ system
s.bianco (frascati) CMS RPC Italia 12 maggio
+-1%
+-0.5 C
25
GAS QUALITY MONITORING
• Gaschromatograph (GC) with columns
optimized for RPC gas mixture components
• Purchased in ~2007 by the INFN group and
used by CERN gas group so far
• Nicely complement to the CMS GC
presently operated by the CERN gas group in
USC.
s.bianco (frascati) CMS RPC Italia 12 maggio
26
STATUS OF GGM AND
GAS QUALITY
•GGM
•Fully integrated in DCS/PVS
•In operation and shift monitoring since 2009
https://twiki.cern.ch/twiki/bin/view/CMS/RPComm
•Stable operation
•Loss of efficiency in 1 gap, to be replaced
• The GGM is performing up to specs
• INFN Gaschromatograph
•Not periodically used
•No procedures for shifter use available yet
s.bianco (frascati) CMS RPC Italia 12 maggio
27
OUTLOOK & GGM+
We propose actions to improve the
monitoring of CMS RPC gas mixture:
1. Review of alarms on gas parameters
(see G.Polese’s talk)
2. Integrate in the gas monitoring the
INFN GC located at SGX5 gas room.
3. GGM+
• p,T correction via HV feedback
• HV scans
s.bianco (frascati) CMS RPC Italia 12 maggio
28
GGM HV feedback test with twin
system in Frascati
With p,T correction on HV
Without p,T correction on HV
s.bianco (frascati) CMS RPC Italia 12 maggio
29
TYPICAL GGM HV SCAN
s.bianco (frascati) CMS RPC Italia 12 maggio
30
GGM preliminary results
on wrong mix problem
April 29th, 2011 - March 3rd, 2011
Good mix
Wrong mix
s.bianco (frascati) CMS RPC Italia 12 maggio
April 29th, 2011 - January 2010
Good mix Good mix
31
RESOURCES
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
M. Abbrescia et al., Gas analysis and monitoring systems for the RPC detector of CMS at the LHC,
[physics/0701014] LNF-06-34-P (Jan 2007) 9p. Presented by S.Bianco at the IEEE2006, S.Diego
(USA).
M.Abbrescia et al., The gas monitoring system for the resistive plate chamber detector of the CMS
experiment at LHC. 2008. 4pp. 18th Hadron Collider Physics Symposium 2007 (HCP 2007) 20-26
May 2007, La Biodola, Isola d'Elba, Italy. Published in Nucl.Phys.Proc.Suppl.177-178:293-296,2008.
CMS Collaboration, The CMS experiment at the CERN LHC, 2008 JINST 3 508004.
L.Benussi et al., Sensitivity and environmental response of the CMS RPC gas gain monitoring system,
JINST 4:P08006,2009,. [arXiv:0812.1710]
L.Benussi et al., The CMS RPC gas gain monitoring system: An Overview and preliminary results.
Nucl.Instrum.Meth.A602:805-808,2009,. [arXiv:0812.11].
L.Benussi et al, Sensitivity and environmental response of the CMS RPC gas gain monitoring system,
LNF-08-27(P), JINST 4:P08006,2009. e-Print: arXiv:0812.1710.
S.Bianco et al., Chemical study of the CMS RPC closed loop gas system, CMS note 2010 - 007
L.Benussi et al., Study of gas purifiers for the CMS RPC detector. [arXiv:1012.5511] (Dec 2010)
L.Benussi et al., A New approach in modeling the response of RPC detectors. [arXiv:1012.5508] (Dec
2010) 13p.
S.Colafranceschi et al., Operational experience of the gas gain monitoring system of the CMS RPC
muon detectors. Nucl. Instrum. Meth.A617:146-147,2010,.
L.Benussi et al., A new approach in modeling the response of RPC detector, presented by
S.Colafranceschi at RPC10, Darmstadt, to appear on NIM (2011)
G.Saviano (for the CMS RPC Collaboration) Results on chemical analysis in the CMS RPC closed
loop, presented at RPC2010, Darmstadt (Germany). To appear on NIM (2011).
https://twiki.cern.ch/twiki/bin/view/CMS/RPComm
https://twiki.cern.ch/twiki/bin/view/CMS/MuonRpcPrivate
s.bianco (frascati) CMS RPC Italia 12 maggio
32
SPARES
s.bianco (frascati) CMS RPC Italia 12 maggio
33
GGM-related studies
on purifiers
•
•
•
1.
2.
3.
•
Study of RPC purifiers at the scaleddown closed loop system located in
the ISR area
Release of contaminants in gas is
correlated to currents increase
Results available at
S.Bianco et al., Chemical study of the CMS RPC closed loop gas system, CMS note 2010 - 007
L.Benussi et al., Study of gas purifiers for the CMS RPC detector. [arXiv:1012.5511] (Dec 2010)
G.Saviano (for the CMS RPC Collaboration) Results on chemical analysis in the CMS RPC closed loop, presented
at RPC2010, Darmstadt (Germany). To appear on NIM (2011).
Currently running, expect run ending
in about 2 months, move test to GIF
s.bianco (frascati) CMS RPC Italia 12 maggio
34