1. LHC Status and CERN’s future plans
Lyn Evans

2. Machine layout

3. Cryodipole overview

4. Short Straight Section overview

5. Bending strength of dipoles

6. Completion of magnet cryostating & tests, 1 March 2007
Cryostating 425 FTE.years
Cold tests 640 FTE.years

7. Descent of the last magnet, 26 April 2007
30’000 km underground at 2 km/h!

8. Dipole-dipole interconnect

9. Dipole-dipole interconnect: electrical splices

10. Magnet interconnections

11. Global pressure test of Sector 4-5, 12 May 2007

12. Flushing machine - Wk 2 January 07
Before
After
Kapton bits
Metal strips
≈ 50 h
+ 8 L of Water

13. Q1.R8

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.

15. Large helium refrigerator for cooling down to 4.5 K
33 50 K to 75 K K to 20 K g/s liquefaction
600 kW precooling to 80 K with LN2 (up to ~5 tons/h)

16. First cool-down of Sector 7-8

17. Hydrodynamic cold compressors for 1.8 K refrigeration
120 g/s GHe from 15 mbar with 4 stages

18. First cool-down of Sector 7-8
Magnet temperature profile along Sector during final cool down to He II

19. Sector 7-8 Cooldown

20. First powering of main quadrupoles

21. Cool-Down until Saturday 14-7-7 Cool-Down Speed

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.

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

24. LHC General Schedule, 5 July 2007
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
General schedule Baseline rev. 4.0

25. European Strategy Group (1/2)
[Quotes from the official statement – July 14, 2006]
Þ Consolidation and upgrade of injectors
Þ LHC upgrade and maximum performance injectors

26. European Strategy Group (2/2)
[Quotes from the official statement – July 14, 2006]
Þ R & D for LHC upgrade and n facility
Þ preparation for n facility

27. CERN accelerator complex

28. Upgrade procedure 1. Lack of reliability:
Ageing accelerators (PS is 48 years old !) operating far beyond initial parameters
Þ need for new accelerators designed for the needs of SLHC
2. Main performance limitation:
Excessive incoherent space charge
tune spreads DQSC at injection in the
PSB (50 MeV) and PS (1.4 GeV) because
of the high required beam brightness N/e*.
Þ 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

29. Upgrade components

30. Layout of the new injectors
SPS
PS2
SPL PS
Linac4

31. Linac4 building and infrastructure
klystron hall (above ground)
accelerating tunnel
H- source & RFQ

32. Linac4 and SPL buildings
SPL tunnel
Linac4 klystron hall
SPL klystron gallery
Linac4 tunnel

33. Linac4 beam characteristics
Stage 1: Linac4 (1/3)
Linac4 beam characteristics
Ion species H-
Output energy
160 MeV
Bunch frequency
352.2 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

34. Linac4 structures Stage 1: Linac4 (2/3) 352.2 MHz H- source RFQ
chopper
DTL
CCDTL
PIMS
3 MeV
50 MeV
102 MeV
352.2 MHz
160 MeV

35. Direct benefits of the new linac
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

36. LPSPL and SPL beam characteristics 2 2’ CDR2 “LPSPL” for SPS & LHC
Stage 2: LPSPL + PS2 (1/3)
LPSPL and SPL beam characteristics
Stage 2 2’
CDR2
“LPSPL” for SPS & LHC
“SPL”
Energy (GeV)
3.5 4 5
Beam power (MW)
0.19
4 - 8
Rep. frequency (Hz) 50
Protons/pulse (x 1014)
1.4
1.2 1
Av. Pulse current (mA) 40 20
Pulse duration (ms)
0.57
1.9
0.4
Bunch frequency (MHz)
352.2
Physical length (m)
430
~460
535
3 different designs:
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

37. PS2 beam characteristics PS2 PS
Stage 2: LPSPL + PS2 (2/3)
PS2 beam characteristics
PS2 PS
Injection energy kinetic (GeV)
4.0
1.4
Extraction energy kinetic (GeV)
~ 50
13/25
Circumference (m)
1346
628
Maximum intensity LHC (25ns) (p/b)
4.0 x 1011
1.7 x 1011
Maximum intensity for fixed target physics (p/p)
1.2 x 1014
3.3 x 1014
Maximum energy per beam pulse (kJ)
1000 70
Max ramp rate (T/s)
1.5
2.2
Repetition time at 50 GeV (s)
~ 2.5
1.2/2.4
Max. effective beam power (kW)
400 60

38. Direct benefits of the LPSPL + PS2
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

39. Upgrade the LPSPL into an SPL (multi- MW beam power at 2-5 GeV):
Stage 2’: SPL
Upgrade the LPSPL into an SPL (multi- MW beam power at 2-5 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 (2nd 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 b-unstable isotopes to a b-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, m capture-cooling-acceleration (20-50 GeV) and storage

40. Planning … CDR 2 3 MeV test place ready Linac4 approval
Start for Physics
SPL & PS2 approval