Introduction

1. Introduction • Where we are: • Detailed document ~40 pages with rough cost estimate • Now being prepared for CMS Phase 2 for RRB meeting on Oct. 28 • Being kept very confidential, since sensitive, and scope and cost could change significantly • Was discussed at MB today… • Costing within the *muon* section is the subject of today’s GMM • ECFA HL-LHC workshop 1-3 October • Talks covering all four LHC detectors, but costs not to be discussed • Alexei Safonov “New challenges for muon detection & triggering…” • Paolo Iengo (ATLAS) “Longevity and expected performance of existing muon…” • Marcello Abbrescia on “Novel Gas Detector & Technology R&D” • A good set of topics for upcoming GMMs in September (Sept 16, 23)

2. Update on Phase 2 forward muon cost • For RRB document • Costs were last presented at General Muon Meeting (GMM) on 15-July • Discussion forums: • GMMs on Mondays at 5 p.m. in 40-R-B10 • Upgrade Project Office (UPO) meetings biweekly Friday afternoons • Forward detector working group (FDWG), esp. ME0 tagger

3. Elements of the costing • Aging and longevity of existing subsystems and their electronics in high radiation environment of HL-LHC • DT electronics • GIF, GIF++ longevity tests • Muon trigger and redundancy • GEM stations GE1/1 and GE2/1, each 2 layers, 1.55-2.4 • RPC stations RE3/1 and RE4/1, each one layer, 1.7-2.4 • Please note that GRPC costs for the moment need more work and will be discussed in next GMM (Sep 16 tbc) • Rapidity extension beyond 2.4 • ME0 within Particle Flow (gas) endcap calorimeter, aka PFCAL • 6 layers of GEMs, cover eta 2.16-4.0

4. Costing table – details later Notes on quality of estimate: • GE1/1, GE2/1, and DT longevity have detailed assessment of costs available. • RE3/1, RE4/1, and ME0 have preliminary costing needing review. • GIF++ longevity tests no detailed costing yet available. Mid-July cost 8 MChF (minicrates) 10.6 MChF 6.6 MChF

5. Aging and longevity • Minicrate numbers from Cristina: • NB upgrade management understands trigger rate motivation • Wants to see aging/longevity details – what ASICs die, what alternatives exist, etc. • GIF and GIF++ studies of existing detectors: • Based on simply guessing 200 KChF for each of 3 detectors • May or may not be “CORE” costs according to Upgrade Management… is it M&O? Is it R&D?

6. “Representative” upgrade • Combines GE1/1, GE2/1, RE3/1, and RE4/1 together • Disentangle GEM from RPC costs (next 2 slides)

7. GEM costing • GE1/1 was carefully costed and reviewed • Reviewed Feb-May and then approved by an independent committee of experienced managers prior to MB presentation at DESY • GE2/1 and ME0 costs were extrapolated from GE1/1 • Chamber areas, channel counts, etc.

8. GE1/1 and GE2/1 • Add redundancy to trigger where badly needed • “The addition of high-precision chambers in the forward region has been shown to dramatically lower the attainable momentum threshold in the trigger” • “In the first and second stations, where the trigger can be improved by high-granularity detectors, two layers of triple-GEMs are foreseen (GE1/1 and GE2/1).”

9. GE1/1 cost • Chambers 0.846 MChF: • 72 m2 of chambers, thus 11.8 KChF/m2 • Electronics 2.491 MChF: • 553K channels, thus 4.5 ChF/channel • Services 0.180 MChF: • Although gas and cooling lines partially exist already • Installation and commissioning 0.105 MChF • Total 3.622 MChF (~10% accuracy) • Unchanged from mid-July

10. GE2/1 cost – extrapolated from GE1/1 • Chambers 1.369 MChF: • Use 116 m2 of chambers times 11.8 KChF/m2 • Electronics 2.491 MChF: • Same cost as GE1/1 (same channels as GE1/1 because finer for eta 2.1-2.4, but coarser for 1.6-2.1) • Services 0.380 MChF: • Add 0.2 MChF for additional gas and cooling lines • Installation and commissioning 0.105 MChF • Total 4.345 MChF (~20% accuracy) • Unchanged from mid-July

11. ME0 (small) muon tagger at back of new HE • Depends on endcap calorimeter replacement and availability of ~25cm at back of new HE • Rapidity from 2.16-4.0 • 2.16 dovetails with GE1/1 coverage • 4.0 is consistent with forward pixel tracker option – perhaps optimistic given need for muon shielding • Reason for 6 finely segmented layers: • The only muon station for eta>2.4 • Need redundancy for excellent neutron rejection • Need lever arm and redundancy for excellent “pointing” (high-Pt selection) New HE m ME0 Additional EE/HE coverage m ME0

12. ME0 cost – extrapolated from GE1/1 • Chambers 0.623 MChF: • Use 53 m2 of chambers times GE1/1 estimate 11.8 KChF/m2 • Electronics 4.982 MChF: • 1.06 million channels, double the channel count of GE1/1 • Average 0.48 cm2/channel, for example: 0.06 cm x 8 cm • Compare ME1/1A strips of area 20 cm2 (0.41-0.58 cm) x 40 cm • Services 0.380 MChF: • Same as GE2/1 (estimate could be refined esp. LV and HV!) • Installation and commissioning 0.210 MChF • Double the GE1/1 cost, due to complexity of HE integration • Total 6.195 MChF (~30% accuracy)

13. RE3/1 and RE4/1 • “Improved multi-gap RPCs offer excellent timing precision, which can be used to effectively reject neutron-induced background hits, and an excellent signature for hypothetical heavy stable charged particles (HSCP); such RPCs are envisioned for the 3rd and 4th muon stations (RE3/1 and RE4/1).”

14. RE3/1 and RE4/1 for fine timing, covering eta 1.7-2.4 • Costs for GRPC and GEM combined in the table for brevity • RPC cost has increased: • July 2.6 MChF • Now 3.7 MChF – why? -GEM = RPC 1.6 MChF 1.1 MChF 0.8 MChF 0.56 MChF 0.2 MChF 0.2 MChF 3.7 MChF

15. Imad GRPC presentation at DESY, pg. 31 • Linkhttps://indico.cern.ch/conferenceDisplay.py?confId=254443

16. RE3/1 and RE4/1 for fine timing, covering eta 1.7-2.4 • 1.6 MChF for chambers (same) • Calculate using 11622 euros/m2 x 1.2 ChF/euro x 58 m2 x 2 stations • 1.1 MChF for electronics (vs. previous 0.526 M) • Imad: 0.526 MChF: 3777 euros/m2 x 1.2 ChF/euro x 58 m2 x 2 stations • Additional missing items 0.598 MChF, from GE1/1 costing: • Crate mTCA 0.218 M (one crate shared by 2 stations, same as GE1/1) • Optolinks 0.115 M (assume half of GE1/1) • Power supplies HV+LV 0.265 M (assume half of GE1/1) • Cables HV+LV not included (86K), DCS+DSS monitoring (50K) • Clearly the estimate needs to be refined… • 0.76 MChF (0.380 per station) for services (same as GE2/1) • Versus previous 0.5 M that included installation and commissioning • 0.210 MChF installation & commissioning (2x GE2/1) broken out • Total 3.67MChF (~30% accuracy) • was 2.64 MChF

17. Costing conclusions • Need refinement prior to RRB: • Minicrate motivation needs beefing up for management • GIF and GIF++ need to decide if these costs are allowable • GE1/1 and GE2/1 costing in decent shape • ME0 would be good to have some simulation support for choice of granularity and number of layers • RE3/1 and RE4/1 need review and refinement of costing • Marcello Abbrescia will look into this • HV and LV costs: can be large, alternate designs can be contemplated

18. Next steps? • R&D plans for present RPC longevity and aging • GMM of Sept. 16: Gabriella • Marcello discussion of RPC plans and costing • GMM of Sept. 16: Marcello • ECFA talks – present to GMM before Oct. 1-3 workshop • Suggest Sept. 23: Alexei, Marcello • NB need convergence on plans, costs well before RRB (Oct. 28-30) • Plan for light post-ECFA discussion at GMM on Oct. 7 • Matters become urgent by the GMM of Oct. 14

19. Backup slides

20. Phase 2 forward muon cost summary: • 7.966 MChF for GE1/1 (3.622 ~10%) and GE2/1 (4.344 ~20%) • 2.644 MChF for RE3/1 and RE4/1 (~40% accuracy) • 6.605 MChF for small ME0 muon tagger (~40% accuracy) • These total 17.2 MChF (+-4.7 MChF linear addition) • Option for forward muon iron toroids25.5 MChF (+-7.3 MChF) • NB economies of scale can reduce costs of chambers and electronics 2-3x if same technology used in HE replacement • NB justification from simulations urgently needed for RE3/1, RE4/1, and toroids • And more detailed justification for the design of GE2/1, ME0 tagger • More details on following slides…

21. Text description of forward muon upgrade costing Baseline forward muon upgrades: • GE1/1:  2 layers of GEMs in the eta range 1.55-2.2; most salient motivation is for the muon trigger: lower muon Pt threshold from ~25 to ~15 GeV.  Obviously well costed & reviewed already. • GE2/1:  2 layers of GEMs in the eta range 1.65-2.4, adds redundancy to 2nd station, most salient motivation is to provide acceptable single muon trigger rate in rapidity region 2.1-2.4 with threshold of ~25 GeV. Base the cost estimate on having similar segmentation to GE1/1, extrapolate production (not R&D) costs from GE1/1. • RE3/1 and/or RE4/1:  1 layer of multi-gap GRPCs covering eta 1.8-2.4, motivated primarily by fine timing to identify muon vertex and to provide a good handle on slow particles.  The proponents claim this technology is inexpensive, and these would be single chambers, so 1 or two stations could optimistically be 0.5x or 1.0x the cost of GE1/1, respectively (some R&D for TDCs and CMS compatible readout probably required). ImadLaktineh has cost estimates in his DESY Upgrades Week talk. • ME0 small front tagger: covers rapidity 2.2-4.0, to be costed assuming 6 layers of GEMs, 2x finer segmentation than GE1/1.  Note that it is possible to reduce cost per area for chambers and cost per channel electronics up to a factor of 3 over GE1/1 if HE is rebuilt with this basic technology, since economies of scale that are thought to be possible will be needed for that.  We may need to add some cost item that represents additional shielding and iron to improve field strength within the space of the present eta=3 cone. Iron toroids option: motivation is triggering capability at high rapidity (assume coverage 2.4-4.0), overlap with rapidity range of LHCb, ability to capture a large rate of dimuons from e.g. B0s→mm.  Currently thought unlikely, since HF needs to be relocated and the current HF may withstand 3000 fb-1.  Also forward tracker needs to achieve decent (<4%) momentum resolution to resolve B0s and B0d peaks.  Very well costed already for the basic iron, magnet, support structure, and need to add cost of 3 or 4 stations of double-layer detectors, by scaling up from the GE1/1 cost estimate. Other options that have been discussed but not to be costed now: • Large ME0: diminishes the case for GE1/1, only possible if calorimeter rebuilt, and requires negative arguments that CSC station ME1/1 is insufficient for rapidity 1.5-2.1. • Back tagger: thought far inferior to front tagger: long lever arm for matching with forward pixel upgrade, much iron contributing multiple scattering, and larger so more costly.

22. NB: options not included in cost estimate • Large ME0 as part of rebuilt HE • Diminishes the case for GE1/1, requires negative arguments about CSC capability or longevity • Back tagger behind HF: seems inferior to front tagger • Long lever arm for matching with forward pixel upgrade • Lots of iron in the path, so more multiple scattering • Larger, so more costly

23. ME0 small and large muon taggers at back of a new HE • Coverage options: • In red: small ME0 ring (top), large ME0 ring (bottom) • {1.5, 2.4} < |h| < 3.5 or so • Best region for muons (more bending and less multiple scattering) • Inner radius shielding needed • Will limit maximum h • New technology allows >>1 MHz/cm2 • “Integrated” option • Build all of HE with GEM technology, for example New HE m ME0 Additional EE/HE coverage m ME0

24. 3. Small ME0 front tagger, part of new HE • Covers eta 2.2-4.0 • On the low side, dovetails with GE1/1 and overlaps aligned ME1/1 • On the high side, depends on shielding but optimal to match forward pixel tracking • Costing assumes 6 layers of GEM technology • Standalone, so need excellent rejection of neutrons, etc. • 0.623 MChF for chambers: 52.8 m2 scaled a la GE1/1 • Only 4.4 m2 per layer x 6 layers x 2 ends • 4.982 MChF for electronics: • For this high rapidity assume twice as many channels as GE1/1 (1106K, 0.48 cm2/channel) • 0.500 MChF for shielding and iron to shape B field • 0.500 MChF for services • Total 6.605 MChF

25. Forward muon upgrades - conclusions • A plausible scenario has been defined for Phase 2 forward muon upgrades • Refinements are needed <October RRB • Understanding future DCFEB installations • Plan for verifying longevity of the CSCs at GIF, GIF++, etc. • Working out details of new detectors to improve capabilities • Working out details of new detectors to extend eta • Building the physics justifications (except GE1/1) • Cost estimates need review • Internal first, later external • At request of UPO, the cost values will be excised from these Indico slides by tonight…