370 likes | 516 Views
ATLAS RPC phase-2 proposal. Completion of the detector for the barrel muon trigger via the installation of new trigger stations in the inner layer of the spectrometer (currently equipped only with MDTs) Increase the number of measurement stations from 2 3
E N D
ATLAS RPC phase-2 proposal • Completion of the detector for the barrel muon trigger via the installation of new trigger stations in the inner layer of the spectrometer (currently equipped only with MDTs) • Increase the number of measurement stations from 2 3 • Increase the number of independent layers from 6 9 RPC3 RPC2 RPC1 RPC0 (BI) D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
ATLAS RPC phase-2 proposal • The inner layer was already considered in the original project of the barrel trigger detector, but at that time the need for the 3rd station was not stringent and it was cancelled • Trigger performance improvements with the new RPC inner layer: • larger acceptance • The new chambers will substantially increase the trigger coverage by filling the acceptance holes due to the barrel toroid support structures • increased selectivity • The larger lever arm and the improved spatial and time resolution of the new RPCs will allow to apply a sharper momentum cut • increased chamber redundancy and longevity • the new layer will increase the redundancy well above the current 3/4 low-pt majority. This will also allow tooperate the middle chambers at lower voltage, decreasing theintegrated charge, without loss in the overall trigger efficiency D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
Barrel trigger coverage LVL1 barrel • High-Pt trigger acceptance currently limited at ~72% • due to non-instrumented regions in: • feet + elevators (partial recovery in LS1) • toroid (and ribs) in BM chambers of small sectors • Holes are not projective and 3/3 RPC chambers • are required in the trigger • with RPC BI chambers use 3/4 request η=0.0 0.4 0.75 1.0 D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
Barrel trigger coverage Single muon MC study for different trigger options current trigger logic D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
Redundancyexploitation The produced charge, responsible for the detector aging, can be reduced by decreasing the operating voltage (this is equivalent to work at lower rate and much lower current) The detector efficiency will consequently decrease - the loss in efficiency is compensated by a less stringent requirement in low-pt trigger: 3/4 2/4 majority - the rejection power would be guaranteed by the additional RPC in the BI chambers 2/4 3/4 D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
Requirements on the new RPCs • According to Atlas requirements the qualification tests were done taking as reference luminosity L=1034 cm-2 s-1, assuming 10 years of running at max background rate of 100 Hz/cm2(including a safety factor of 5 wrt simulation) • Expected max rate in new inner layer ~1 kHz/cm2: • need to improve the long term RPC rate capability to sustain the LHC luminosity in phase-2 • Limited space available for the installation in the inner layer: ~5cm • Reduced gas gain: • thinner gap 2 1 mm • thinner electrodes 1.8 1.2 mm • increased amplification in front-end electronics • Improved spatial and time resolution: • timing is improved by reducing the gap thickness • use ToT and charge centroid to improve spatial resolution • Reduced detector thickness • higher-quality mechanical structures D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
CMS RPC phase-2 proposal Two types of upgrades proposed for the CMS RPC muon system: Aging and longevity: built in 2003 and installed in 2007, must continue to operate without significant degradation degradation (<eff> = 95%, CS < 3, noise < 1 Hz/cm2) well beyond the design expectations of the LHC; in particular, with respect to a large integrated radiation dose and also a very long time period of operation. • Upgrade of high eta region: keep performance of trigger and low pT<20GeV threshold even at an increased luminosity • Background rejection and muon reconstruction • Costant trigger rate with PT < 20 GeV • HZZ*2m, 4m; Ht+t-mX; etc • NEW STATIONS RE3/1 and RE4/1 Technical Proposal in progress due July 2014 D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
RE3/1 & RE4/1 • Proposed to cover the very forward region (1.6< |h| <2.4) • 144 chambers (about 1.5-2.0 m2 area) for the inner (ring n.1) region of disks 3 and 4 • Rate: 1-2 kHz/cm2 • x5 limit tested for existing RPC chambers • Integrated charge: 1-2 C/cm2 @ 3000fb-1 Barrel muon system is covered with 8 layers of chambers (58 hits max) Endcap region is covered with 8 layers (28 hits max) High eta region is covered with 4 layers (24 hits max) D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
CMS RPC in muon reconstruction • Recovery of efficiency thanks to RPC tracking During RUN1 the stability of the muon system has been assured thanks to the 2 independent trigger/detector systems. A major CSC faults occurred in the 2012 (7 chambers off in ring1) but thanks to the RPC (ring 2) we were able to recover part of the inefficiency even in this region. With a full coverage the system will be stable in case of any trouble. D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
CMS RPC in muon trigger • All 3 muon triggers (RPC, DT, CSC) contribute to the stability of the muon trigger efficiency and to the control of the rate. • From the 2016 all the muon data will be used in a unique algorithm in order to have more robust system in the view of the lumi/background increment foreseen. D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
Joint ATLAS-CMS phase 2 R&DCMS-specific • Operation at 1-2kHz/cm2, 1-2 C/cm2 @3000fb-1 • Improved time resolution (10-100)ps • Background reduction • Secondary vertices • iRPC • Large area, improved, multigap RPC • with HPL / glass electrodes D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
1. Electrodes • Lower resistivity materials will be investigated • construction of low resistivity HPL electrodes higher rate • construction of low resistivity glass electrodes higher rate + multigap (timing) • Thinner electrodes will be tested to improve the S/N ratio and the spatial resolution • construction of gas volumes with thin HPL electrodes D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
2. Chamber prototypes • construction of reduced size prototype • construction of module -1 prototypes D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
3. High performance FEE CMS production chamber • Prototype developed by R.Cardarelli • Tests on 2mm gaps • CMS • turn-on efficiency curve shifted by ~460V • ATLAS • comparison in lab with the ATLAS FE • at the same efficiency: x7 reduced charge; • fully efficient up to 7 kHz/cm2 at GIF Preliminary results ATLAS lab Total charge vsHVeff Highlighted points at 90% efficiency Red: ATLAS FE/ Blue: new Si FE D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
The block diagram of the preamplifier The same scheme can be used for both Si and SiGe technology for a comparison Si technology SiGe technology D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
Signal and noise from Si-amplifier and SiGe-amplifier Pulses recorded from a 500 micron diamond sensor irradiated by 241Am source SiGe amplifier Silicon amplifier Signal amplification x1.4 improvement (same scale) Noise comparison (same scale) D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
Costestimation • Il presente progetto mira a realizzare, in forma di multi-project presso la ditta Europractice, 40 circuiti full custom da 8 canali ciascuno • Il programma prevede i passi seguenti • Dis.+Test circuito analogico: 1 giro di fonderia, 15 kE • Dis +Test Circuito analogico+digitale: “ “ 50 “ • Ottimizzazione “ “ “ “ 50 “ • Produzione di 40 prototipi “ “ 50 “ • I primi tre punti sono già coperti da altri progetti-finanziamenti. Si richiede il finanziamento di un giro di fonderia dedicato alla produzione dei prototipi da utilizzare nel proposto R&D D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
4. The Quest for ecogases • The European Community has prohibited the production and use of gas mixtures with Global Warming Power > 150 (GWP(CO2) = 1) • This is valid mainly for industrial (refrigerator plants) applications • Scientific laboratories would be excluded • CERN could require to stick to these rules anyhow • C2H2F4 is the main component of the present RPC gas mixture: • GWP(C2H2F4) = 1430, GWP(SF6) = 23900, GWP(iC2H10) = 3.3 • C2H2F4and SF6Crucial to ensure a stable working point in avalanche • Similar problem for CF4(GWP = 5800) used in GEMs for time resolution • On the physical and chemical properties of this components we: • Designed FE electronics and chambers • Did all performance, ageing and calibration tests D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
4. The Quest for ecogases: Plan • Test moleculessimilar to C2H2F4 but with lower GWP • C3H2F4– tetrafluoropropene (GWP=4) • Should replace C2H2F4 as automotive air-conditioning refrigerant • C2H4F2– difluoroethane (GWP=120) • Also studied to replace C2H2F4 as a refrigerant • C2HF3Cl2 (GWP=93), • others… • Plan to measure all the detector response parameter (time, charge spectrum, streamer separation, noise, efficiency, possibly drift velocity, etc) • HUGE PARAMETER SPACE, NEED TO DIVIDE MEASUREMENTS BETWEEN FACILITIES • Test at the GIF++ will follow on a short list of candidates ecogases to measure the performance in a realistic environment • Rate capability, performance under stress, HF yield already being setup at GIF • New ageing tests (to be performed also at GIF++) D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
RPC standard gases and their candidate ecoreplacements D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
First results on new gas mixturesforRPCs Gas mixturestested: Ar/C4H10/TP 83-3-15 withincreasing % of SF6 Preliminary Ref: B.Liberti et al, RPC2014 Beijing • TFP has a strong effect both in quenching and in keeping the charge at low level • mixtures are promising even for avalanche working mode with an appropriate FEE and a dedicated chamber layout A long R&D program is needed to analyze all the proposed gases and variants First with cosmics, then at GIF Single-gap ATLAS prototype, read on the oscilloscope, averagecharge vs. efficiency D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
The Quest for ecogases: ATLAS Tor Vergata lab Spazio per foto e qualche riga sul laboratorio di Tor Vergata D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
The Quest for ecogases: CMS Frascati lab TIME&CHARGE WAVEFORM 12 RPC IN CR TELESCOPE AND T, H CONTROLLED HUT 2 independent gas mix lines for event-by-event comparison (photo) digitizer 2 independent gas mixing lines Plot adc charge distrib VME adc+tdc gaschromatograph D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
The Quest for Ecogasescharacterizing interaction of candidate ecogases with RPC materials • Chemistry • Reactivity • Outgassing • Production of HF ? • Production of other contaminants? • Ex.: CF3I under discharge releases CF3 strong acid and corrosive • Before and after irradiation D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
The Quest for Ecogascharacterizing interaction of candidate ecogases with RPC materials manalysis at CMS Frascati and associates (SapienzaIngegneriaMateriali, ENEA, Politecnico Torino) • Photo GC-MS • (photo) XRD • Photo) FTIR • (photo) SEM-EDS • Optical sensors for RPC • M.Caponero et al., Use of fiber op4c technology for rela4ve humidity monitoring in RPC detectors JINST 8 (2013) T03003 • S.Grassini et al., Gas monitoring in RPC by means of non-‐invasive plasma-‐coated POF sensors JINST 7 (2012) P12006 • Gas mixtures for RPC • S.Colafranceschi et al., A study of gas contaminants and interac4on with materials in RPC closed loop systems JINST 8 (2013) T03008 • S.Colafranceschi et al., Performance of the Gas Gain Monitoring system of the CMS RPC muon detector and effec4ve working point fine tuning INST 7 (2012) P12004 • L.Benussi et al., A New approach in modeling the response of RPC detectors Nucl.Instrum.Meth. A661 (2012) S182-‐ S185 • L.Benussi et al, Study of gas purifiers for the CMS RPC detector Nucl.Instrum.Meth. A661 (2012) S241-‐S244 • Materials for gaseous detectors • G.Saviano et al., A study of film and foil materials for the GEM detector proposed for the CMS muon system upgrade accepted by JINST (2014) D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
The Quest for Ecogascharacterizing interaction of candidate ecogases with RPC materials • Optical sensors for gas contaminants • Developed for HF detection and tested at GIF • S.GrassiniM.ParvisL.Benussi S.Bianco D.Piccolo, Gas monitoring in RPC by means of non-invasive plasma-coated POF sensors JINST 7 (2012) P12006 • Simple, optical, compact, inexpensive • Test and optimize for ecogases • Develop compact and inexpensive standalone readout • If successful, study deployment D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
5. Irradiation tests D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
Single Event Effects study on the FE boards of the improved RPC (2015-2017) • Motivations: study of radiation transient effects on the FE electronics of the iRPC • Study : cross section measurement of the transient fenomena induced by neutrons on the open input FE boards. We plan to use the following facilities: the Triga Mark II reactor in Pavia and the Louvain cyclotron. The first one covers a energy range till 18MeV which can be extended till 50MeV by the second one. • Setup : a measurement station has been already assembled and used for previous tests. The station has been instrumented with : VME crate, LVoltage PS , VME scalers, NIM crate and NIM modules, PC. • Additional costs to be addressed: • irradiation and targets for flux measurement at Triga Mark II 4kEuro • irradiation and transport costs for Louvain 7kEuro D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
6. New trigger electronics (ATLAS) • The current system is not compatible with the Phase-2 trigger requests • 2 trigger levels (L0 + L1) • minimum 500 kHz L0 rate, minimum 200 kHz L1 rate • 6 µs L0 latency, 30 µs L1 latency • use of GBT system for the distribution of the LHC timing signals • readout system based on Felix • The current on-detector electronics will be replaced with the new DCT boxes (Data Collector Transmitter, about 800 in total) • use of FPGAs instead of ASICs for the on-detector electronics • the DCT box will collect RPC front-end data, and perform some simple logic before sending the data off-detector • Most of the trigger logic will be located in the off-detector (USA15) new Sector Logic boards (64 in total): • increased algorithm flexibility, easier operations and maintenance, no radiation D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014 29
New trigger scheme • on-detector • off-detector • readout data • RPC3 • GBT fibres • DCT • 208 • control data • 416 • Init/control PC • Felix • 2 • trigger data • GBT fibres • Sector Logic • DCT • 64 • 416 • RPC2 • 1 per crate • trigger fibres • RPC1 D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014 30 • 208 • to MuCTPi / CTP • RPC0 • to ethernet switch / ROD • DCT
R&D: new trigger electronics • Additional trigger logic with respect to the current one is being defined: • Increased trigger coverage could be feasible by changing the trigger algorithm (and possibly by adding new RPCs in the inner barrel layer) • Increased steepness of the trigger turn-on curve could be feasible thanks to the improved spatial resolution • Muoncharge info could be added to the trigger data • Trigger thresholds could be fully programmable and more flexible (possibly > 6) • Interest in the project expressed by the INFN groups • Bologna, Napoli, Roma, Roma Tor Vergata(about 10 physicists, 4 FTE) • R&D: • 2 commercial FPGA evaluation boards (3 k€ ciascuna) • 2 adapter boards (1 k€ ciascuna) • 1 prototype (5 k€) • Total R&D: 13 k€ (2015: 6 k€ - 2016: 2 k€ - 2017: 5 k€) D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014 31
Financial Requests (2015-2017) D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
spares D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014
HPL: R&D relativo alla produzione di lastre di HPL a bassa resistività. Obiettivo è il raggiungimento di un valore di resistività inferiore di un ordine di grandezza rispetto a quello attualmente utilizzato (1÷6 x 1010 Ohm cm). Questo R&D è di interese comune ATLAS-CMS ma sarà seguito da CMS che ha studiato e contribuito allo sviluppo della produzione di HPL per RE4 con una nuova ditta di laminati (Puricelli) dopo la chiusura della ditta Panpla che aveva prodotto tutto l’ HPL per gli RPC degli esperimenti a LHC. La misura di resitività sarà fatta da CMS mentre il test della long term conductivity da ATLAS • Acquisto di un batch di HPL (1 batch= 80 lastre da 1.6 m x 3.2 ;) . Questo quantitativo è sufficiente per un certo numero di prototipi da 1mq per entrambi gli esperimenti e per circa 5 prototipi0 (fulls size) per ogni esperimento : 8 kEuro • Sperimentazione bassa resistività presso la ditta Puricelli : 12 kEuro (basato su circa 50 test ) • Misure di resistività: costruzione di uno strumento portatile per la misura di resistività (alimentatore,adc,elettrovalvole, consumables) 7 keuro • Test di long term conductivity sull’HPL : 3 keuto • Trasporti: le lastre saranno tagliate presso una ditta milanese e inviate alla GT per la costruzione dei prototipi: 5 keuro D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014