Luminosity and time estimates Mike Lamont Thanks for discussion: R. Assmann, R. Bailey, M. Ferro-Luzzi, S. Fartoukh, O. Bruning

Disclaimer The future is a strange place Aim of the exercise is to establish some realistic numbers given accepted constraints All numbers to be treated with a modicum of circumspection Optimistic numbers can be treated as upper limits 24/02/10 Luminosity estimates

Some formulae Halving time to luminosity – 2 IPs Assume radiation damping compensates diffusion And then optimize fill length Following Ruggiero 24/02/10 Luminosity estimates

Luminosity estimates Calculate peak luminosity given the usual inputs Bunch current, number of bunches, emittance, beta*, crossing angle Calculate luminosity lifetime given Luminosity, cross-section Beam-gas lifetime IBS growth rates Optimize fill length given an assumed turnaround time Given fill length & luminosity lifetime – calculate integrated luminosity per fill Multiply up 24/02/10 Luminosity estimates

~ 3 hour minimum. Assume 4 hours here – optimism bias Turn around time Physics to physics Phase Time [mins] Ramp down and pre-cycle 60 Pre-injection preparation and checks 15 Checks with set-up beam (tunes, orbit etc.) Nominal injection sequence 20 Ramp preparation 5 Ramp 25 Squeeze 30 Adjust 10 TOTAL 180 ~ 3 hour minimum. Assume 4 hours here – optimism bias 24/02/10 Luminosity estimates

Note: ramp down – precyclecombo Perform ramp down of main bends, quads, IPQs, triplets etc. Up to 40 minutes from 3.5 TeV values At the same time precycle all other circuits Sextupoles, correctors, compensators, warm magnets etc 24/02/10 Luminosity estimates

Less than one hour turn around (after 8 years’ optimization) LEP No-one ever thought it could be as smooth as: Less than one hour turn around (after 8 years’ optimization) 24/02/10 Luminosity estimates

Of course it wasn’t always as good as that 24/02/10 Luminosity estimates

Operation month/year After a year or so… 30 days per month 3 day technical stop & recovery [~2 days machine development] Absorbed into unavailability for this exercise 60% machine availability During which time we are dedicated to trying to do physics 4 weeks of ions (plus one week setup) Other requests e.g. Totem Shutdown Assume around 7 months proton physics per year approx. 200 days, optimization possible with a 2 year cycle 24/02/10 Luminosity estimates

The Hubner factor Standard method Take schedule physics time (minus MD, scheduled stops etc.) Take peak luminosity time number of seconds Multiply by Hubner factor Usually taken to be around 0.2 Takes into account luminosity lifetime, turnaround, unplanned interventions etc Here I have explicitly calculated luminosity lifetime, optimal fill length etc. End up with a HF of around 0.3 Long luminosity lifetime, long fills, 4 hour turn around The LHC has to be good, rashly make the assumption that we can make it so. 24/02/10 Luminosity estimates

Out with the crystal ball 24/02/10 Luminosity estimates

Jorg’s approved steps to 2 MJ Simple HF 24/02/10 Luminosity estimates

Or what you can do with 2.9 MJ TT40 Damage during 2004 High Intensity SPS Extraction / Goddard, B ; Kain, V ; Mertens, V ; Uythoven, J ; Wenninger, J Or what you can do with 2.9 MJ During high intensity extraction on 25/10/04 an incident occurred in which the vacuum chamber of the TT40 magnet QTRF4002 was badly damaged. The beam was a 450 GeV full LHC injection batch of 3.4 1013 p+ in 288 bunches, and was extracted from SPS LSS4 with the wrong trajectory 4.4 e12 at 3.5 TeV 88 bunches at 5 e10 24/02/10 Luminosity estimates

Massimo Giovannozzi et al 2010++ Massimo Giovannozzi et al 24/02/10 Luminosity estimates

Int Lumi per month [pb-1] 2011 3.5 TeV: run flat out at ~100 pb-1 per month Nb ppb Total Intensity MJ beta* Peak Lumi Int Lumi per month [pb-1] 50 ns 432 7 e10 3 e13 17 2.5 7.4 e31 ~63 (34) Pushing intensity limit 796 5.1 e13 31 1.4 e32 ~116 (63) 16% nominal Should be able to deliver around 1 fb-1 24/02/10 Luminosity estimates

Round beam approximation Beam beam tune shift Round beam approximation 7 e10 gives around 0.009 24/02/10 Luminosity estimates

Constraints to 2015 Energy Splice consolidation 2012++ Should open the way to 6.5/7 TeV ~2 years at 6.5 TeV before hitting 7 TeV Beam intensity limits from collimation phase 1 40% maximum – less with imperfections 2012 + X: modification of DS 2012 + X + 1: DS collimators buys nominal intensity 2014/2015: Full phase 2 buys nominal and ultimate intensity If X > 0 then assume everything done after 2014 run Until then 40% limit holds – which is not a major disaster 24/02/10 Luminosity estimates

NB: limit, not prediction Collimation phase 2 NB: limit, not prediction 24/02/10 Luminosity estimates

2015 - 2020? Arrive at end 2014 (with a bit of luck) On the schedule: 7 TeV Around 20% nominal performance 10 - 20 fb-1 in the bag On the schedule: LINAC4 (lose 6 months of proton physics) DS collimators in – good for nominal Collimation phase 2 – good for ultimate Phase 1 upgrade (1 year shutdown plus re-commissioning) 24/02/10 Luminosity estimates

2015 - 2020? Statistical error halving time Accumulate X fb-1 per year 2015 - 2020? Statistical error halving time Accumulate X fb-1 per year A naïve 3 more years at the same rate to halve the error Flat lining soon becomes uninteresting However, we’re hardly flat-lining at this stage Clear that having yet to achieve nominal performance, another major shutdown would not be optimal at this stage 24/02/10 Luminosity estimates

Plan A 2012++ – splice consolidation and DS collimation prep. 2013 – 6.5 TeV – ~25% nominal 2014 – 6.5 TeV – ~40% nominal 2015(?) – LINAC4 (6 months), collimation phase 2: No phase 1 upgrade Ions, 2 months recommissioning, 4 month protons Presumably contingent on delivered integrated luminosity 2016: 7 TeV – nominal performance 2017 – 2020 A) Push to nominal and then flat-line (more-or-less) B) Push towards ultimate 2020 – 2022 – possible upgrade Presumably contingent on delivered integrated luminosity etc. 24/02/10 Luminosity estimates

Plan A 24/02/10 Luminosity estimates

To 2014 2012: splice consolidation (and DS collimator prep (?)) 2013: 6.5 TeV ~25% nominal intensity 2014: 6.5 TeV ~40% nominal intensity Year Months energy beta ib nb Peak Lumi Lumi per month Int Lumi Int Lumi Cul 2010 8 3.5 2.5 7 e10 796 1.4 e32 - 0.1 2011 9 0.9 1.0 2012 2013 6 6.5 1 1 e11 720 1.2 e33 5.4 7 2014 1404 2.3 e33 1.8 13 20 24/02/10 Luminosity estimates

At least in the same ball park Independent estimate Courtesy of a rather pessimistic but perhaps more realistic Massi Ferro-Luzzi Year Months energy beta ib nb Peak Lumi Lumi per month Int Lumi Int Lumi Cul 2010 6 3.5 2.5 7 e10 720 1.0 e32 - 0.1 2011 9 9 e10 2.0 e32 1 1.1 2012 2013 6.5 9 e32 0.45 2.7 3.8 2014 1404 1.7 e33 0.6 5.3 9.1 At least in the same ball park Hubner Factor ~ 0.2 24/02/10 Luminosity estimates

2015 – 2016 to nominal 2015: Take a 6 month hit for LINAC4 & collimators phase 2, say, Optimist Year Months energy beta ib nb Peak Lumi Lumi per month Int Lumi Int Lumi Cul 2015 4 7 1 11 e10 2808 6 e33 4.6 18 43 2016 0.55 1 e34 7.4 52 96 Might hope to hit nominal in 2016 Massi 2015 4 7 1 9 e10 2808 3.6 e33 2 8 17 2016 9 0.55 6.2 e33 3.2 29 46 24/02/10 Luminosity estimates

Beyond 2016 Assumptions PS at increased injection energy plus LINAC4 are good for ultimate (after a suitable commissioning period) ~1.7 x 1011 can be swallowed by the SPS Give or take a long shutdown LHC can swallow ultimate intensity “Ultimate intensity is challenging for the LHC. Many systems at technological limits with little or no margin.” (R. Assmann – Cham 2010) Stay at or around nominal Able to push towards ultimate 24/02/10 Luminosity estimates

2010 - 2020 24/02/10 Luminosity estimates

Conclusions Luminosity estimates for the next ten years presented Biased towards the optimistic Nominal performance by 2016 21st century Hubner factors Big errors bars and numbers should be treated with care particularly after 2016 Important to gain some operational experience!!! 24/02/10 Luminosity estimates