1. CMS RPC R&D for phase 2 Two types of upgrades proposed for the CMS RPC muon system: 1.Aging and longevity: installed in 2007, must continue to operate without significant degradation 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. D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 20141 2.Redundancy in the forward region: keep performance of trigger and low p T threshold even at an increased luminosity H  ZZ*   ; H       X; etc NEW STATIONS RE3/1 and RE4/1 Technical Proposal in progress due July 2014

2. RE3/1 & RE4/1 – 144 chambers (about 1.5-2.0 m 2 area) for the inner (ring n.1) region of disks 3 and 4 – Rate: 1-2 kHz/cm 2  x5 limit tested for existing RPC chambers – Integrated charge: 1-2 C/cm 2 @ 3000fb -1 D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 20142 Proposed to cover the very forward region (1.6< |  | <2.4)

3. CMS RPC in muon reconstruction D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 20143 Recovery of efficiency thanks to RPC tracking

4. Joint ATLAS-CMS phase 2 R&D CMS-specific Operation at 1-2kHz/cm 2, 1-2 C/cm 2 @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 20144

5. ATLAS RPC phase-2 proposal 5 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 RPC0 (BI) RPC3 RPC2 RPC1 D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014

6. ATLAS RPC phase-2 proposal 6 The inner layer was already considered in the original project of the barrel trigger detector, but at that time the need for the 3 rd 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 to operate the middle chambers at lower voltage, decreasing the integrated 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

7. Barrel trigger coverage 7 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 LVL1 barrel 1.0 0.75 0.4 η=0.0 D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 2014

8. Barrel trigger coverage 8 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

9. Redundancy exploitation 9 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

10. Requirements on the new RPCs 10 According to Atlas requirements the qualification tests were done taking as reference luminosity L=10 34 cm -2 s -1, assuming 10 years of running at max background rate of 100 Hz/cm 2 (including a safety factor of 5 wrt simulation) Expected max rate in new inner layer ~1 kHz/cm 2 : 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

11. 1. Electrode D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 201411

12. 2. Chamber prototypes D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 201412

13. 3. FEE D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 201413

14. 4. The Quest for Ecogas Qui lista candidati, piano misure, setups disponibili a frascati e TV D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 201414

15. The Quest for Ecogas characterizing interaction of candidates with RPC materials Chemistry Reactivity Outgassing HF production Before and after irradiation D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 201415

16. Setup and refs for materials studies Op4cal sensors for RPC gas – 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 – Patent deposit ZEOSENSORS (n. RM2011A000621 24/11/2011) 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 GEM – 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 201416

17. 5. Irradiation tests D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 201417

18. 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

19. spares D.Boscherini for the ATLAS Coll. and S.Bianco for the CMS Coll. R&D RPC phase2 - Rome May 9th 201419

20. 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 10 10 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 Tot35 HPL20 Transportation5 Resistivity Meas10 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