LHC Status and CERN s future plans. Lyn Evans

Transcription

1 LHC Status and CERN s future plans Lyn Evans

2 Machine layout L. Evans EDMS document no

3 Cryodipole overview Equivalent dipoles Jan Jan Jan Jan Jan Jan Jan Jan-08 Cold masses delivered Cryodipoles cold tests passed Cryodipoles prepared for installation Cryodipoles assembled Cryodipoles assigned to position in ring Cryodipoles installed L. Evans EDMS document no

4 Short Straight Section overview Equivalent SSS Jan Jan Jan Jan Jan Jan Jan Jan-08 Cold masses delivered SSS assembled SSS cold test passed SSS assigned to position in ring SSS prepared for installation SSS installed L. Evans EDMS document no

5 Bending strength of dipoles Cold mass Firm 1 Firm 2 40 Int transf func (Tm/kA) Firm 3 upper limit for single magnet (3 sigma) Units lower limit for single magnet (3 sigma) Magnet progressive number AT-MAS -40 L. Evans EDMS document no

6 Completion of magnet cryostating & tests, 1 March 2007 Cryostating Cold tests 425 FTE.years 640 FTE.years L. Evans EDMS document no

7 Descent of the last magnet, 26 April km underground at 2 km/h! L. Evans EDMS document no

8 Dipole-dipole interconnect L. Evans EDMS document no

9 Dipole-dipole interconnect: electrical splices L. Evans EDMS document no

10 Magnet interconnections 100% General Advancement of Interconnects per Sector 16-July-2007 Close W & Jumper 90% Weld Package I & VAC tests 80% N-Line Package 70% 60% 50% Cryo-Lines Welding & Testing Electrical Interconnects & QA per halfcell IC preparation 40% 30% 20% 10% 0% sector 1-2 sector 2-3 sector 3-4 sector 4-5 sector 5-6 sector 6-7 sector 7-8 sector 8-1 L. Evans EDMS document no

11 Global pressure test of Sector 4-5, 12 May 2007 L. Evans EDMS document no

12 Flushing machine - Wk 2 January 07 Before After Kapton bits Metal strips 50 h + 8 L of Water L. Evans EDMS document no

13 Q1.R8 L. Evans EDMS document no

14 Cooldown of Sector 7-8 From RT to 80K precooling with LN tons of LN2 (64 trucks of 20 tons). Three weeks for the first sector. From 80K to 4.2K. Cooldown with refrigerator. Three weeks for the first sector tons of material to be cooled. From 4.2K to 1.9K. Cold compressors at 15 mbar. Four days for the first sector. L. Evans EDMS document no

15 Large helium refrigerator for cooling down to 4.5 K K to 75 K K to 20 K 41 g/s liquefaction 600 kw precooling to 80 K with LN2 (up to ~5 tons/h) L. Evans EDMS document no

16 First cool-down of Sector 7-8 LHC sector 78 - First cooldown Temperature (K) Return temperature Magnet temp. Supply temperature Active cooling in all thermal shields and cryogenic tranfer lines. All magnets isolated. Thermal shield temp. Active cooling in all thermal shields and cryogenic tranfer lines. All magnets isolated /01/07 18:00 21/01/07 18:00 27/01/07 18:00 Re-start of active cooling for cryogenic transfer lines 02/02/07 18:00 08/02/07 18:00 Re-start of active cooling for magnets 14/02/07 18:00 20/02/07 18:00 26/02/07 18:00 04/03/07 18:00 Time (UTC) 10/03/07 18:00 Supply temperature Return temperature Magnet temperature (average over sector) Thermal shields temp. (average over sector) L. Evans EDMS document no

17 Hydrodynamic cold compressors for 1.8 K refrigeration 120 g/s GHe from 15 mbar with 4 stages L. Evans EDMS document no

18 First cool-down of Sector 7-8 Magnet temperature profile along Sector 7-8 during final cool down to He II L. Evans EDMS document no

19 Sector 7-8 Cooldown L. Evans EDMS document no

20 First powering of main quadrupoles L. Evans EDMS document no

21 Cool-Down until Saturday Cool-Down Speed Avg. Cold Mass Temperature /5/07 6:00 7/6/07 6:00 7/7/07 6:00 7/8/07 6:00 7/9/07 6:00 7/10/07 6:00 7/11/07 6:00 7/12/07 6:00 7/13/07 6:00 7/14/07 6:00 7/15/07 6:00 7/16/07 6:00 7/17/07 6:00 7/18/07 6:00 7/19/07 6:00 Date planned [K] measured [K] data S7-8 [K] L. Evans EDMS document no

22 Installation & equipment commissioning Procurement problems of remaining components (DFBs, collimators) now settled Good progress of installation and interconnection work, proceeding at high pace in tunnel Numerous non-conformities intercepted by QA program, but resulting in added work and time Technical solutions found for inner triplet problems and repair well underway. Commissioning of first sectors can proceed by isolating faulty triplets, but will have to be re-done with repaired triplets (needing additional warm-up/cooldown cycles) First sector cooled down to nominal temperature and operated with superfluid helium; teething problems with cold compressor operation have now been fixed. Second sector being cooled down. Power tests have started. L. Evans EDMS document no

23 General schedule Engineering run originally foreseen at end 2007 now precluded by delays in installation and equipment commissioning. 450 GeV operation now part of normal setting up procedure for beam commissioning to high-energy General schedule has been revised, accounting for inner triplet repairs and their impact on sector commissioning All technical systems commissioned to 7 TeV operation, and machine closed April 2008 Beam commissioning starts May 2008 First collisions at 14 TeV c.m. July 2008 Luminosity evolution will be dominated by our confidence in the machine protection system and by the ability of the detectors to absorb the rates. No provision in success-oriented schedule for major mishaps, e.g. additional warm-up/cooldown of sector L. Evans EDMS document no

24 LHC General Schedule, 5 July 2007 General schedule Baseline rev. 4.0 Global pressure test &Consolidation Cool-down Powering Tests Interconnection of the continuous cryostat Leak tests of the last sub-sectors Inner Triplets repairs & interconnections Global pressure test &Consolidation Flushing Cool-down Warm up Powering Tests L. Evans EDMS document no

25 European Strategy Group (1/2) [Quotes from the official statement July 14, 2006] Consolidation and upgrade of injectors LHC upgrade and maximum performance injectors L. Evans EDMS document no

26 European Strategy Group (2/2) [Quotes from the official statement July 14, 2006] R & D for LHC upgrade and ν facility preparation for ν facility L. Evans EDMS document no

27 CERN accelerator complex L. Evans EDMS document no

28 Upgrade procedure 1. Lack of reliability: Ageing accelerators (PS is 48 years old!) operating far beyond initial parameters need for new accelerators designed for the needs of SLHC 2. Main performance limitation: Excessive incoherent space charge tune spreads ΔQ SC at injection in the PSB (50 MeV) and PS (1.4 GeV) because of the high required beam brightness N/ε*. ΔQ SC with N ε N ε b X, Y b X, Y R 2 βγ : number of : normalized transverse emittances R : mean radius of protons/bunch the accelerator βγ :classical relativistic parameters need to increase the injection energy in the synchrotrons Increase injection energy in the PSB from 50 to 160 MeV kinetic Increase injection energy in the SPS from 25 to 50 GeV kinetic Design the PS successor (PS2) with an acceptable space charge effect for the maximum beam envisaged for SLHC: => injection energy of 4 GeV L. Evans EDMS document no

29 Upgrade components Proton flux / Beam power 50 MeV 160 MeV Linac2 Linac4 1.4 GeV 4 GeV PSB LPSPL Output energy 26 GeV 50 GeV 450 GeV 1 TeV PS SPS PS2 SPS+ LPSPL: Low Power Superconducting Proton Linac (4 GeV) PS2: High Energy PS (~ 5 to 50 GeV 0.3 Hz) SPS+: Superconducting SPS (50 to1000 GeV) SLHC: Superluminosity LHC (up to cm -2 s -1 ) DLHC: Double energy LHC (1 to ~14 TeV) 7 TeV ~ 14 TeV LHC / SLHC DLHC L. Evans EDMS document no

30 Layout of the new injectors SPS PS2 SPL PS Linac4 L. Evans EDMS document no

31 Linac4 building and infrastructure klystron hall (above ground) H - source & RFQ accelerating tunnel L. Evans EDMS document no

32 Linac4 and SPL buildings SPL tunnel Linac4 klystron hall SPL klystron gallery Linac4 tunnel L. Evans EDMS document no

33 Stage 1: Linac4 (1/3) Linac4 beam characteristics Ion species H - Output energy 160 MeV Bunch frequency MHz Max. repetition rate 2 Hz Beam pulse duration 0.4 ms Chopping factor (beam on) 62% Source current 80 ma RFQ output current 70 ma Linac current 64 ma Average current during beam pulse 40 ma Beam power 5.1 kw Particles p. pulse Transverse emittance (source) 0.2 mm mrad Transverse emittance (linac) 0.4 mm mrad L. Evans EDMS document no

34 Stage 1: Linac4 (2/3) Linac4 structures 3 MeV 50 MeV 102 MeV 160 MeV H - source RFQ chopper DTL CCDTL PIMS MHz L. Evans EDMS document no

35 Stage 1: Linac4 (3/3) Direct benefits of the new linac Stop of Linac2: End of recurrent problems with Linac2 (vacuum leaks, etc.) End of use of obsolete RF triodes (hard to get + expensive) Higher performance: Space charge decreased by a factor of 2 in the PSB => potential to double the beam brightness and fill the PS with the LHC beam in a single pulse, => easier handling of high intensity. Potential to double the intensity per pulse. Low loss injection process (Charge exchange instead of betatron stacking) High flexibility for painting in the transverse and longitudinal planes (high speed chopper at 3 MeV in Linac4) First step towards the SPL: Linac4 will provide beam for commissioning LPSPL + PS2 without disturbing physics. Benefits for users of the PSB Good match between space charge limits at injection in the PSB and PS => for LHC, no more long flat bottom at PS injection + shorter flat bottom at SPS injection: easier/ more reliable operation / potential for ultimate beam from the PS More intensity per pulse available for PSB beam users (ISOLDE) up to 2 More PSB cycles available for other uses than LHC L. Evans EDMS document no

36 Stage 2 2 CDR2 LPSPL for SPS & LHC SPL 3 different designs: Stage 2: LPSPL + PS2 (1/3) LPSPL and SPL beam characteristics Energy (GeV) Beam power (MW) Rep. frequency (Hz) Protons/pulse (x ) Av. Pulse current (ma) Pulse duration (ms) Bunch frequency (MHz) Physical length (m) 430 ~ CDR2 (2006) based on 700 MHz high-gradient cavities LPSPL for LHC (2007) with low beam power, for the needs of the LHC SPL at higher energy, for the needs of neutrino production L. Evans EDMS document no

37 Stage 2: LPSPL + PS2 (2/3) PS2 Injection energy kinetic (GeV) Extraction energy kinetic (GeV) ~ 50 13/25 Circumference (m) Maximum intensity LHC (25ns) (p/b) 4.0 x x Maximum intensity for fixed target physics (p/p) 1.2 x x Maximum energy per beam pulse (kj) Max ramp rate (T/s) Repetition time at 50 GeV (s) ~ /2.4 Max. effective beam power (kw) PS2 beam characteristics PS L. Evans EDMS document no

38 Stage 2: LPSPL + PS2 (3/3) Direct benefits of the LPSPL + PS2 Stop of PSB and PS: End of recurrent problems (damaged magnets in the PS, etc.) End of maintenance of equipment with multiple layers of modifications End of operation of old accelerators at their maximum capability Safer operation at higher proton flux (adequate shielding and collimation) Higher performance: Capability to deliver 2.2 the ultimate beam for LHC to the SPS => potential to prepare the SPS for supplying the beam required for the SLHC, Higher injection energy in the SPS + higher intensity and brightness => easier handling of high intensity. Potential to increase the intensity per pulse. Benefits for users of the LPSPL and PS2 More than 50 % of the LPSPL pulses will be available (not needed by PS2) => New nuclear physics experiments extension of ISOLDE (if no EURISOL) Upgraded characteristics of the PS2 beam wrt the PS (energy and flux) Potential for a higher proton flux from the SPS L. Evans EDMS document no

39 Stage 2 : SPL Upgrade the LPSPL into an SPL (multi- MW beam power at 2-52 GeV): 50 Hz rate with upgraded infrastructure (electricity, water, cryo-plants, ) 40 ma beam current by doubling the number of klystrons in the superconducting part Possible users EURISOL (2 nd generation ISOL-type RIB facility) => special deflection system(s) out of the SPL into a transfer line => new experimental facility with capability to receive 5 MW beam power => potential of supplying β-unstable isotopes to a β-beam facility Neutrino factory => energy upgrade to 5 GeV (+70 m of sc accelerating structures) => 2 fixed energy rings for protons (accumulator & compressor) => accelerator complex with target, μ capture-cooling-acceleration (20-50 GeV) and storage L. Evans EDMS document no

40 Planning 3 MeV test place ready Linac4 approval CDR 2 SPL & PS2 approval Start for Physics L. Evans EDMS document no