s.bianco (frascati) CMS RPC Italia 12 maggio 1 Stefano Bianco per CMS Frascati 1. GAS S.Bianco Colafranceschi Benussi Piccolo, … 2. SENSORS4UPGRADE S.Bianco S.Buontempo Caponero Breglio…, …

s.bianco (frascati) CMS RPC Italia 12 maggio 2 GAS 1. 1.Gas review al cern sull’incident della rottura del flussimetro SF6 (0.30% --> 0.39%) piuttosto produttiva: e minute di Pigi

s.bianco (frascati) CMS RPC Italia 12 maggio 3 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 Mass Flow Controller – follow-up SF 6 C2H2F4C2H2F4 iC 4 H 10

s.bianco (frascati) CMS RPC Italia 12 maggio 4 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% SF6 Mass Flow Controller 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 5 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 6 PRELIMINARY APRIL %-->0.30% SF6 0.30%-->0.39% SF6 +-10% GGM down :-(((( HV scans

s.bianco (frascati) CMS RPC Italia 12 maggio %-->0.30% SF6 0.30%-->0.39% SF6

s.bianco (frascati) CMS RPC Italia 12 maggio 8 ADC

9 ADC

10 CONCLUSIONS 0/ Il gas group effettuera’ misure di GC con il sistema CMS in USC 1/2 volte a settimana (Beatrice) 2. 2.Il GC INFN verra’ installato in SGX5 e operato da RPC

s.bianco (frascati) CMS RPC Italia 12 maggio 11 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 12 CONCLUSIONS 2/3 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…… 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). 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

s.bianco (frascati) CMS RPC Italia 12 maggio 13 CONCLUSIONS 3/ Abbiamo trovato e capito alcuni GGM analysis bugs 2. 2.Il transiente si vede 3. 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. 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 14 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 15 POSSIBILE RI- ORGANIZZAZIONE GAS GAS () 1.Gas quality …. GC () 2.Gas calibration ….GGM (Frascati) 3.Liason to gas group (Benussi) 4.Detector (leak tests + ???) ()

s.bianco (frascati) CMS RPC Italia 12 maggio 16 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 17 SPARE SLIDES

s.bianco (frascati) CMS RPC Italia 12 maggio 18 RPC GAS MONITORING 1. 1.Gas Gain Monitoring (GGM) Monitoring of working point for changes due to differences among clean, after- purifiers, before-purifiers gas mixtures. Monitoring of charge ratios (afterPurifiers/clean, beforePurifiers/clean) allows cancellation of p,T,H effects 2. 2.Gas Quality Monitoring Monitoring of chemical composition of gas mixtures

s.bianco (frascati) CMS RPC Italia 12 maggio 19 USC55UXC55 SGX5 RPCs #1 Fresh gas Purifiers Mixer Humidifier GC F-F- pH other RPCs #2 Before purifiers RPCs #3 After purifiers Gas quality monitoring Gas gain monitoring GC+others (half wheel pick- up points) CMS DAQ Performance detector monitoring - ENV. CONTROL gas parameters Ambient parameters 19 RPC GAS SYSTEM AND MONITORING

s.bianco (frascati) CMS RPC Italia 12 maggio 20 GGM Eight single gap RPCs with charge readout in a cosmics telescope Three sets of gaps: clean gas, before- purifier gas, after-purifier gas. Cancellation of p,T by ratioing. fully integrated in DCS/PVSS In operation and shift monitoring since

s.bianco (frascati) CMS RPC Italia 12 maggio 21 GGM 

s.bianco (frascati) CMS RPC Italia 12 maggio 22 GGM

s.bianco (frascati) CMS RPC Italia 12 maggio 23 Gas Gain Monitoring Performance Avalanche Streamer 0.3% SF 6 0% SF 6 Anode charge in avalanche- streamer transition region monitors shifts in working point. SENSITIVITY ~ 20V Coherent effects cancel out due to system redundancy. The two-gap ratio cancels out LONG-TERM ENVIRONMENTAL EFFECTS AT THE +-3% LEVEL +-3%rms

s.bianco (frascati) CMS RPC Italia 12 maggio 24 GGM on PVSS

s.bianco (frascati) CMS RPC Italia 12 maggio 25 GGM TWIN IN FRASCATI CMS LAB +-1% C T,H controlled hut Gaschromatograph DAQ system

s.bianco (frascati) CMS RPC Italia 12 maggio 26 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 27 STATUS OF GGM AND GAS QUALITY GGM Fully integrated in DCS/PVS In operation and shift monitoring since 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 28 OUTLOOK & GGM Review of alarms on gas parameters (see G.Polese’s talk) 2. 2.Integrate in the gas monitoring the INFN GC located at SGX5 gas room GGM+ p,T correction via HV feedback HV scans We propose actions to improve the monitoring of CMS RPC gas mixture:

s.bianco (frascati) CMS RPC Italia 12 maggio 29 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 30 TYPICAL GGM HV SCAN

s.bianco (frascati) CMS RPC Italia 12 maggio 31 GGM preliminary results on wrong mix problem April 29th, January 2010 April 29th, March 3rd, 2011 Good mix Wrong mixGood mix

s.bianco (frascati) CMS RPC Italia 12 maggio 32 RESOURCES 1. 1.M. Abbrescia et al., Gas analysis and monitoring systems for the RPC detector of CMS at the LHC, [physics/ ] LNF 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 pp. 18th Hadron Collider Physics Symposium 2007 (HCP 2007) May 2007, La Biodola, Isola d'Elba, Italy. Published in Nucl.Phys.Proc.Suppl : , CMS Collaboration, The CMS experiment at the CERN LHC, 2008 JINST L.Benussi et al., Sensitivity and environmental response of the CMS RPC gas gain monitoring system, JINST 4:P08006,2009,. [arXiv: ] L.Benussi et al., The CMS RPC gas gain monitoring system: An Overview and preliminary results. Nucl.Instrum.Meth.A602: ,2009,. [arXiv: ] 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: S.Bianco et al., Chemical study of the CMS RPC closed loop gas system, CMS note L.Benussi et al., Study of gas purifiers for the CMS RPC detector. [arXiv: ] (Dec 2010) 9. 9.L.Benussi et al., A New approach in modeling the response of RPC detectors. [arXiv: ] (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: ,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)

s.bianco (frascati) CMS RPC Italia 12 maggio 33 SPARES

s.bianco (frascati) CMS RPC Italia 12 maggio 34 GGM-related studies on purifiers Study of RPC purifiers at the scaled- down closed loop system located in the ISR area Release of contaminants in gas is correlated to currents increase Results available at 1. 1.S.Bianco et al., Chemical study of the CMS RPC closed loop gas system, CMS note L.Benussi et al., Study of gas purifiers for the CMS RPC detector. [arXiv: ] (Dec 2010) 3. 3.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