LHC status and commissioning plans

LHC in 4 slides Lest we forget Progress to date Present schedules Consequent plan for 2008

R.Bailey, DESY, December 2007 LHC dipoles (1232 of them) operating at 1.9K 7TeV 8.33T 11850A 7MJ

R.Bailey, DESY, December 2007 And plenty more magnets besides … Several thousand magnets Thousands of Interconnects Electrical Fluids Vacuum

R.Bailey, DESY, December 2007 And plenty of power circuits … Several hundred Power Circuits

R.Bailey, DESY, December 2007 Lest we forget – QRL Installation started in sector 7-8 in July 2003 Installation started in sector 7-8 in July 2003 Geometry, weld quality, procedures, leaks, support tables … Geometry, weld quality, procedures, leaks, support tables … Installation finished November 2006 (sector 78 by CERN) Installation finished November 2006 (sector 78 by CERN)

R.Bailey, DESY, December 2007 Lest we forget – Main magnets First magnet installed March 2005 First magnet installed March 2005 Peak of ~1000 dipoles stored, allowed magnet sorting Peak of ~1000 dipoles stored, allowed magnet sorting Last dipole lowered April 26 th 2007 Last dipole lowered April 26 th 2007 Cryostating425 FTE. years Cryostating425 FTE. years Cold tests640 FTE. years Cold tests640 FTE. years Transport30’000 km underground at 2 km/h! Transport30’000 km underground at 2 km/h!

R.Bailey, DESY, December 2007 Lest we forget – Triplets – Heat exchanger problem During the pressure test of Sector 7-8 (25 November 2006) the corrugated heat exchanger tube in the inner triplet failed by buckling at 9 bar (external) differential pressure. During the pressure test of Sector 7-8 (25 November 2006) the corrugated heat exchanger tube in the inner triplet failed by buckling at 9 bar (external) differential pressure. The inner triplet was isolated and the pressure test of the whole octant was successfully carried out to the maximum pressure of 27.5 bar, thus allowing it to be later cooled down. The inner triplet was isolated and the pressure test of the whole octant was successfully carried out to the maximum pressure of 27.5 bar, thus allowing it to be later cooled down. Reduced-height of corrugations and annealing of copper near the brazed joint at the tube extremities accounted for the insufficient resistance to buckling. Reduced-height of corrugations and annealing of copper near the brazed joint at the tube extremities accounted for the insufficient resistance to buckling. New tubes were produced with higher wall thickness, no change in corrugation height at ends, and e-beam welded collars to increase distance to the brazed joint. New tubes were produced with higher wall thickness, no change in corrugation height at ends, and e-beam welded collars to increase distance to the brazed joint. Installation of these tubes was made in situ. Installation of these tubes was made in situ.

R.Bailey, DESY, December 2007 Lest we forget – Triplets – Supports problem Q1 supports at IP 5L On Tuesday March there was a serious failure in a high-pressure test at CERN of a Fermilab-built “inner-triplet” series of three quadrupole magnets

R.Bailey, DESY, December 2007 Lest we forget – Triplets – Supports solution Requirements for repair Requirements for repair Must be implemented in situ Must be implemented in situ Does not displace the fixed points of the assembly Does not displace the fixed points of the assembly React loads with sufficient stiffness to limit deflection at 150 kN design load React loads with sufficient stiffness to limit deflection at 150 kN design load Acts at any temperature between 300K and 2K Acts at any temperature between 300K and 2K To be implemented in Q1 and Q3 To be implemented in Q1 and Q3 Solution adopted Solution adopted Affixed at Q1 non-IP end and at Q3 IP end Affixed at Q1 non-IP end and at Q3 IP end Transfer load at all temperatures Transfer load at all temperatures Limits support deflections Limits support deflections Compound design with Invar rod and aluminium alloy tube Compound design with Invar rod and aluminium alloy tube Attached with brackets to cold mass and cryostat outer vessel Attached with brackets to cold mass and cryostat outer vessel Status Status All triplets repaired by September All triplets repaired by September Problem solved Problem solved

R.Bailey, DESY, December 2007 Commissioning of the power converters PC 18kV for the dipole circuits 400V for the others Water UPS for all converters above 4 kA DCCT Short Circuit UA, UJ, RR tunnel, UJ 1720/1720 installed Commissioning campaign on short circuit From mid 2006 to late % commissioned

R.Bailey, DESY, December 2007 Machine commissioning without beam is by sector 8 distinct sectors for cryogenic and powering Picture today Order was originally determined by installation sequence

R.Bailey, DESY, December 2007 Shielded bellows on the cold interconnects (PiMs)

R.Bailey, DESY, December 2007 Plug in Module in equivalent cold position

R.Bailey, DESY, December 2007 RF mole Polycarbonate shell Diameter 34mm exterior 30mm interior Total weight ~15 g (ball 8g) RF characteristics 40MHz resonantcircuit Generates 20V between copper electrodes Battery powered Over 2hr lifetime Capacitive coupling to BPM electrodes 1V ⇒ ~5mV -45db Coupling BPM trigger threshold at ~3mV

R.Bailey, DESY, December 2007 Commissioning of sector 45 (without triplet) Water in the oil of Compressor station Leak to insulating vacuum Stop for repair Leak to insulating vacuum Stop for repair Almost ready for powering

R.Bailey, DESY, December 2007 Beam tests October 2004 October 2007

R.Bailey, DESY, December 2007 Performance goals Nearly all the parameters are variable Nearly all the parameters are variable Number of particles per bunch  Number of particles per bunch  Number of bunches per beamk b Number of bunches per beamk b Relativistic factor (E/m 0 )  Relativistic factor (E/m 0 )  Normalised emittance  n Normalised emittance  n Beta function at the IP  * Beta function at the IP  * Crossing angle factorF Crossing angle factorF Full crossing angle  c Full crossing angle  c Bunch length  z Bunch length  z Transverse beam size at the IP  * Transverse beam size at the IP  * “Thus, to achieve high luminosity, all one has to do is make (lots of) high population bunches of low emittance to collide at high frequency at locations where the beam optics provides as low values of the amplitude functions as possible.” PDG 2005, chapter 25

R.Bailey, DESY, December 2007 Overall commissioning strategy for protons (est d. 2005) Hardware commissioning Machine checkout Beam commissioning 43 bunch operation 75ns ops 25ns ops I Install Phase II and MKB 25ns ops II Stage A BC No beamBeam D I.Pilot physics run First collisions First collisions 43 bunches, no crossing angle, no squeeze, moderate intensities 43 bunches, no crossing angle, no squeeze, moderate intensities Push performance Push performance Performance limit cm -2 s -1 (event pileup) Performance limit cm -2 s -1 (event pileup) II.75ns operation Establish multi-bunch operation, moderate intensities Establish multi-bunch operation, moderate intensities Relaxed machine parameters (squeeze and crossing angle) Relaxed machine parameters (squeeze and crossing angle) Push squeeze and crossing angle Push squeeze and crossing angle Performance limit cm -2 s -1 (event pileup) Performance limit cm -2 s -1 (event pileup) III.25ns operation I Nominal crossing angle Nominal crossing angle Push squeeze Push squeeze Increase intensity to 50% nominal Increase intensity to 50% nominal Performance limit cm -2 s -1 Performance limit cm -2 s -1 IV.25ns operation II Push towards nominal performance Push towards nominal performance

R.Bailey, DESY, December 2007 LHCb during Stage A Displace bunches in one ring (n on m) Displace bunches in one ring (n on m) 4 per SPS cycle in 43 bunch, 16 per SPS cycle in 156 bunch mode 4 per SPS cycle in 43 bunch, 16 per SPS cycle in 156 bunch mode Dedicated runs for LHCb (n on n) ? Dedicated runs for LHCb (n on n) ? Squeeze in point 8 (2m limit for ‘bad’ LHC dipole polarity) Squeeze in point 8 (2m limit for ‘bad’ LHC dipole polarity) All values for All values for nominal emittance nominal emittance 7TeV 7TeV Parameters Rates in 8 kbkbkbkbN  * 8 (m)Luminosity (cm -2 s -1 ) Events/crossing 1 on << 1 4 on << 1 4 on on on on on

R.Bailey, DESY, December 2007 Stage B physics run Parameters Beam levels Rates in 1 and 5 Rates in 2 and 8 kbkbkbkbN  * 1,5 (m) I beam proton E beam (MJ)Luminosity (cm -2 s -1 ) Events/crossingLuminosity Events/crossing << Relaxed crossing angle (250  rad) Relaxed crossing angle (250  rad) Start un-squeezed Start un-squeezed Then go to where we were in stage A Then go to where we were in stage A All values for All values for nominal emittance nominal emittance 7TeV 7TeV 10m  * in points 2 and 8 (will not be like this) 10m  * in points 2 and 8 (will not be like this) Protons/beam ≈ few Stored energy/beam ≤ 100MJ

R.Bailey, DESY, December 2007 Stage C physics run Parameters Beam levels Rates in 1 and 5 Rates in 2 and 8 kbkbkbkbN  * 1,5 (m) I beam proton E beam (MJ)Luminosity (cm -2 s -1 ) Events/crossingLuminosity Events/crossing << Nominal Nominal crossing angle (285  rad) Nominal crossing angle (285  rad) Start un-squeezed Start un-squeezed Then go to where we were in stage B Then go to where we were in stage B All values for All values for nominal emittance nominal emittance 7TeV 7TeV 10m  * in points 2 and 8 (will not be like this) 10m  * in points 2 and 8 (will not be like this) Protons/beam ≈ Stored energy/beam ≥ 100MJ

R.Bailey, DESY, December 2007 Stage A: routes through the commissioning phases Circulating beam Injection First turn 450GeV initial 450GeV optics 450GeV 2 beams 450GeV Increase I Circulating beam Injection First turn 450GeV initial 450GeV optics 450GeV Increase I Snapback Ramp Top energy checks Top energy Collisions Snapback Ramp Top energy checks Squeeze Pilot physics Ramp both beams Squeeze both beams Beam 2 Beam 1 2 beams 450GeV Collisions Experiment magnets OFF Dipoles OFF

R.Bailey, DESY, December 2007 Beam commissioning to 7 TeV collisions Rings Total [days] 1Injection and first turn2 4 2Circulating beam GeV – initial commissioning GeV – detailed optics studies GeV increase intensity GeV - two beams GeV - collisions1 2 8aRamp - single beam2 8 8bRamp - both beams TeV – top energy checks2 2 10aTop energy collisions1 1 TOTAL TO FIRST COLLISIONS (beam time) 30 11Commission squeeze2 6 10bSet-up physics - partially squeezed1 2 TOTAL TO PILOT PHYSICS RUN (beam time) 44

R.Bailey, DESY, December 2007 Stage A: First collisions Approx 30 days of beam time to establish first collisions Approx 30 days of beam time to establish first collisions Un-squeezed Un-squeezed Low intensity Low intensity Approx 2 months elapsed time Approx 2 months elapsed time Given optimistic machine availability Given optimistic machine availability Continued commissioning thereafter Continued commissioning thereafter Increased intensity Increased intensity Squeeze Squeeze

R.Bailey, DESY, December 2007 Staged commissioning plan for protons Hardware commissioning 450 GeV and 7TeV 2008 Machine checkout Beam commissioning 450 GeV Machine checkout Beam commissioning 7TeV 43 bunch operation Shutdown BC No beamBeam Shutdown Machine checkout Beam Setup 75ns ops25ns ops IShutdown 2009 No beamBeam A

R.Bailey, DESY, December 2007 First beam Beam 2 Beam 1