( LHCMAC Chamonix Summing-upLHC MAC June 15, Third LHC Project Workshop January 2006

( LHCMAC Chamonix Summing-upLHC MAC June 15, Scientific Programme 1) The minimum workable LHC - plans and requirements for beam commissioning, years 1 and 2, Chairman: R. Bailey, Scientific Secretary: S. Redaelli 2) The minimum workable LHC – machine protection and collimation Chairman: R. Schmidt, Scientific Secretary: J. Uythoven 3) The minimum workable LHC – providers’ commitments Chairman: J.J. Gras, Scientific Secretary: S. Bart Pedersen 4) Magnetic Requirements for Commissioning Chairman: E. Todesco, Scientific Secretary: S. Ramberger 5) Experiment-Machine Interface Chairman: K. Potter, Scientific Secretary: D. Macina

( LHCMAC Chamonix Summing-upLHC MAC June 15, Scientific Programme 6) Installation Chairman: T. Pettersson, Scientific Secretary: F. Rodriguez Mateos 7) I-LHC Chairman: O. Brüning, Scientific Secretary: D. Manglunki 8) Sector test – beam Chairman: M. Lamont, Scientific Secretary: V. Kain 9) Sector test – preparation Chairman: P. Strubin, Scientific Secretary: K. Foraz 10) Closing session Chairman: S. Myers, Scientific Secretary: J. Poole

( LHCMAC Chamonix Summing-upLHC MAC June 15, Session 1: Min Workable…commissioning Schedule for ions, Could use ion running as a cool down before a shutdown…. Totem needs special runs with special optics etc Minimum β* of 2m instead of 1m to limit event pile-up <2 initially… Needs new justification for 75ns since electron cloud seems now less critical … Only 50 effective running days per year as a max (50% efficiency) Management of Critical settings… Strong justification for sector test (plus injection test)

( LHCMAC Chamonix Summing-upLHC MAC June 15, Session 1 Min Workable…commissioning Abort gap monitor needed to avoid quenching on every beam dump Nearly all magnetic circuits are needed for day 1 except MCO/MO and skew sextupoles Beta beat maximum of 20%. Justification needed for for initial stages. Feedback priority list tune, chromaticity, orbit, energy… BBQ, PLL If there are no bake-outs in the LSS  impact on ALICE/LHCb (beam gas background)  radiation and electronics in the RF straights LHC requires a new RP procedural approach to be implemented with groups…Relaxed for stages 1 and 2. For stage 3 we are facing final conditions Applications software (and Machine time allocation) etc for optics testing, BPM calibrations, polarity errors, “bad BPMs” On-line model of MAD highly useful

( LHCMAC Chamonix Summing-upLHC MAC June 15, Session 2 Min workable.. Machine Protection & Collimation Safe beam limit at 450 Gev of 10**12 protons at nominal emittance. Impact of smaller emittances 1µm? Scaled to 7Tev limit is at 10**10 (pilot) Majority of interlock systems must be operational for stage 1 Threshold changes for interlocks… needs careful study and proposal Injection protection system must be fully operational for stages beyond 156 bunches Collimator (injection protection, TCDI, TDI) control system needed for sector test (rudimentary version) LBDS requires careful commissioning with pilot beam: optics, aperture, inject/dump energy ramping

( LHCMAC Chamonix Summing-upLHC MAC June 15, Collimation system can be somewhat relaxed for early stages. Tertiary collimators and the background on experiments…Adjustment procedure for the 100 collimators Co-ordination needed for collimation, installation, vacuum. Sum signal (intensity) should be ready for start- up.. BLM urgently need an operational scenario. Machine protection co-ordination (to be done by EiC or special team of MP) Session 2 Min workable.. Machine Protection & Collimation

( LHCMAC Chamonix Summing-upLHC MAC June 15, Session 3 Provider’s Commitments: Controls Collimators; possible delays: impact on bake-outs, installation PLL and mains ripple what to do? RF in good shape. Work ongoing on RF noise (with strong beam loading). CNIC good progress: access from experts at home. User requirements for operational efficiency (all accelerators) Data acquisition and concentration. Who is doing it

( LHCMAC Chamonix Summing-upLHC MAC June 15, Session 4 Magnetic Requirements Hysterisis is NOT a problem for orbit feedback Beta beating estimates now 18/17% (H/V) compared with earlier estimates 19/21% Baseline measurements for stand-alone quads to be discussed (LTC) Measurement accuracy…LEP sc quad experience... How do we minimize the β beat with a circulating beam Use of MQT for operations and applications software. 1 family or more, zero setting or offset? Sorting has been a big success. Gaining factors (2-3) on the non-linear fields seen by the beams. (Responsibility with MEB but any imposed deviations should be aired at LTC).

( LHCMAC Chamonix Summing-upLHC MAC June 15, Session 5 Machine Experiments Interface Commissioning and Running Advisory Group (CRAG) 10fb-1 is highest priority. changing optics, running conditions etc should not delay this goal BUT radiation (collimators etc) may require a cool down time before a shutdown (special low intensity running) Need an accelerator person to be responsible for detector background… Machine bake-out delayed what will be the impact on background. Check IP3 and IP7… Justification of need for injection inhibit without beam dump Masking of experiment interlocks? LHCb polarity change..transparency (W. Herr) to be followed up…beam screen

( LHCMAC Chamonix Summing-upLHC MAC June 15, Session 6 Installation Based on Present Conditions which are being re- examined to produce a new schedule for Spring 06  Delays between 3 and 4 months  Delivery of last 2 sectors (1-2, 2-3) by Aug 2007  Can we operate through winter Magnet polarity. Magnet polarities should be controlled BEFORE installation in the tunnel. Power supply polarity checks Data-base “as installed” needed

( LHCMAC Chamonix Summing-upLHC MAC June 15, Session 7 I-LHC For the early ion we should have an identical magnetic machine as with protons. Use ions as a radiation cool-down time Lead time needed for different species of ions…test stand? Spares 18Ghz system (not 14GHz) Study LEIR and the source (more time needed)..support from AT-VAC Collimation scheme does not yet work. Physics problem. Controls and Machine protection tests in the SPS during 2006

( LHCMAC Chamonix Summing-upLHC MAC June 15, Session 8 Sector Test with Beam (Good to have sum signal from the BPM) (Needs collimator controls (TCDI, TDI)) Vary emittance for quench tests (MAD on line) 10**9 protons for a quench what happens if the quench limit is below Calibration of beam-losses with mJ/m Limit the intensity shot into magnets?? Implications on non-cycling of dipoles: straight to injection current without cycling

( LHCMAC Chamonix Summing-upLHC MAC June 15, Session 8 Sector Test with Beam (MAD on-line model) Sector test will be the first large scale deployment of FESA “Safe beam Parameters will be transmitted over the timing system”…SAFE? During the sector test equipment safety will be ensured by the SPS safe beam system Data for post mortem system (to be furnished by equipment groups.) Implementation of Machine Modes Data exchange between machine and experiments during sector test (telephone)

( LHCMAC Chamonix Summing-upLHC MAC June 15, SESSION 9; Sector Test Preparation Will the sector test (injection test) put at risk circulating beam in 2007? The sector test is part of the LHC installation and NOT a special installation What will be the disruption to the installation and commissioning resulting from a sector test with the new schedule? We should NEVER jeopardize the equipment safety by doing insufficient testing. What really useful information will be able to measure from the sector test if the magnets are not properly cycled etc?

( LHCMAC Chamonix Summing-upLHC MAC June 15, SESSION 9 Usefulness of a sector test after the shutdown (April 07) Why not do the quench limit test in the SPS using an unnecessary LHC superconducting magnet…cryogenic system LHCb gentleman’s agreement sustained LHCb can cope with (would prefer) delayed sector test, and so would many other people.