CONTENT: Beam characteristics and MP concerns BI configuration Operational settings Collimators Planning Shift breakdown Thanks to: P.Baudrenghien, G.Bellodi, B.Goddard, J.J.Gras, D.Jacquet, J.Jowett, M.Lamont, S.Redaelli, F.Roncarolo, M.Sapinsky, R.Steinhagen

Beam Characteristics 12/10/ LHC BBCWGW.Venturini - M.Solfaroli2 Bunch intensity = 7x10 7 ions (5.74 x10 9 charges/bunch) Squeezed to 3.5m Transverse normalized emittance ~1.5/0.8 μm (nominal/used, for the same beam size as for protons) First setup with 2 bunches/beam (still safe and collisions in all IPs Nominal filling scheme (128b) for luminosity production being finalized (see J.Jowett’s slides) Energy of the nominal beam (128b) ~400kJ Possibility of quench in the DSs negligible with this intensity SBF reduction factor still to be decided. Proposal for 2 or 2.5 as it’s the maximum we can do while keeping safe beam measurable (2b beam still

12/10/ LHC BBCWGW.Venturini - M.Solfaroli3 Beam Instrumentation SYSTEMRESPONSIBLECOMMENT Wire ScannerDehning – Sapinsky Safe beam for wire damage ~2.2e13 p and ~9.4e9 ions (including safety factor). Last estimation for p 2.8e13 No quench at 3.5 TeV with 1e13 p. BLMDehningNo change is foreseen on threshold BPMJones – LefevreNo problem – to be used on High sensitivity BCT – FBCTLudwigOK BSRABoccardi It should be OK IF the requested MD time for commissioning/check is allocated BGIDehning – SapinskyTo be commissioned during the MD BSRTRoncarolo Differences in light spectrum and intensity: 3.5TeV: no problem 450GeV: ~1/100 signal intensity w.r.t. protons pilot (close to limit of camera sensitivity). Some possible improvement of the setup could give enough signal Q – Q’Steinhagen * Q depends only on 'frev' which supplied via the BST timing system. * Q' depends only on the Q measurement and the dp/p modulation amplitude. ‘dp/p -> df’ differences are small but can be re-programmed online if necessary. * FBs operate based on the momentum, distributed by the slow timing system.

12/10/ LHC BBCWGW.Venturini - M.Solfaroli4 Settings management Ramp and Squeeze functions are ready in a dedicated Hypercycle (EARLY-IONS_3.5TeV) Most settings identical to protons but: RF (  functions are ready) Xing angles in collisions Collimation To minimize the changes, Xing settings maintained as for p throughout INJECTION, RAMP and SQUEEZE: Xing angle to be set at: 0 μrad for IP1 and IP μrad (external angle) for IP2. As ALICE wants to flip the spectrometer polarity during the run the external angle will be later set at +140 μrad Same Xing angle as for protons and parallel separation for IP8 (no collision required)

12/10/ LHC BBCWGW.Venturini - M.Solfaroli5 Collimation system (I) If possible, no changes to IP7 and IP3 settings all over the cycle –Cross calibration of orbit reading with protons: Inject high intensity p bunch (LOW BPM sensitivity) Correct against reference orbit Inject low intensity p bunch and record orbit (HIGH BPM sensitivity) Inject an Ions bunch and check that orbit is the same Define it as Ions reference orbit –Test ramp with safe Ions beam (2b), collimators at injection settings and OFB on to establish reference orbit up to high energy –During squeeze use same orbit reference as for protons and measure the optics

12/10/ LHC BBCWGW.Venturini - M.Solfaroli6 Collimation system (II) Subsequent ramp with the same collimator settings as for p till the end of the squeeze, then: Keep IP8 separation and Xing angle Change Xing angles as required in IP1, IP2 and IP5 Set-up of TCTs around new collision orbit –As a result only one collimator set-up to be done at top energy Loss maps: –done in 5 configuration for p –Suggested a minimum of 3 (~4 fills) for Injection End of squeeze Collisions SHADOWING OF ZDC…OPEN PROBLEM – to MPP

12/10/ LHC BBCWGW.Venturini - M.Solfaroli7 Planning >

12/10/ LHC BBCWGW.Venturini - M.Solfaroli8 Shift Breakdown from start to first collisions J.Jowet Bunches Total Time [days] both rings Comments I0Re-commission protons11 Following technical stop, establish orbit with low-intensity BPM settings. I1Injection and first turn1(0.25)Magnetically identical to protons; 1 bunch/beam. I2Circulating beam10.25 Magnetically identical to protons. Synchronisation of transfer lines and RF capture at -5 kHz frequency shift. Check lifetime in particular. I3 450 Z GeV initial commissioning Cross-calibration of BPMs from protons. Beam instrumentation setup. Wire-scanner, BGI. I4 450 Z GeV optics checks with two beams 2(0.5) Magnetically identical to protons but do minimal check of energy matching, beta-beating. >0.4 nominal bunch intensity I5450 Z GeV - two beams20.5Otherwise magnetically identical to protons I6Collimation20.5Set-up single stage collimation, loss map to compare with protons. I7Ramp10.5 Start with two beams, Magnetically identical to protons. Check beam dump at various energies. I83.5 Z TeV flat top checks10.5Performed following successful ramp. Collimation setup and loss map. I9 Setup for collisions Z TeV 10.5 Squeeze and transition to zero real crossing angle in ALICE, CMS & ATLAS. LHCb separated, squeezed. Collimation setup. I10Loss maps10.5 Measure to verify hierarchy appropriate for ion beams. test predictions. Verify protection. Stable beam1(0.1)See machine backgrounds ?

12/10/ LHC BBCWGW.Venturini - M.Solfaroli9 Shift Breakdown from start to first collisions J.Jowet Bunches Total Time [days] both rings Comments TOTAL to prepare 5+(1) I11 First collisions+physics 21.5Ramp with two beams, squeeze, checks I12Increase intensity1281Increase bunch number to 128 (Early++ Scheme). Physics128 Parasitic measurements during physics (luminosity evolution, BFPP, etc,...) to test our models and prepare future runs.

12/10/ LHC BBCWGW.Venturini - M.Solfaroli10 Open questions Transverse emittance: as low as possible? 0.8 μm? ADT off? Longitudinal emittance: start without blow-up (in case of need it should be ready (Philippe B.)) Re-steering of transfer lines? LBDS - special tests? Loss maps configuration to be decided Shadowing of ZDC…OPEN PROBLEM – to MPP LHCb dipole and compensator off?