lhc status and cerns future plans lyn evans. l. evans – edms document no. 859415 2 machine layout
TRANSCRIPT
LHC Status and CERN’s future plansLyn Evans
L. Evans – EDMS document no. 859415 2
Machine layout
L. Evans – EDMS document no. 859415 3
Cryodipole overview
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Equ
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dipo
les
Cold masses delivered Cryodipoles assembled
Cryodipoles cold tests passed Cryodipoles assigned to position in ring
Cryodipoles prepared for installation Cryodipoles installed
L. Evans – EDMS document no. 859415 4
Short Straight Section overview
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Equ
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Cold masses delivered SSS assembled SSS cold test passedSSS assigned to position in ring SSS prepared for installation SSS installed
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Bending strength of dipoles
10.07
10.09
10.11
10.13
10.15
0 100 200 300 400 500 600 700 800 900 1000 1100 1200
Magnet progressive number
Int t
ran
sf fu
nc
(Tm
/kA
)
-40
-20
0
20
40
Un
its
Firm 1
Firm 2
Firm 3
AT-MAS
Cold mass
upper limit for single magnet (3 sigma)
lower limit for single magnet (3 sigma)
L. Evans – EDMS document no. 859415 6
Completion of magnet cryostating & tests, 1 March 2007
Cryostating 425 FTE.years
Cold tests 640 FTE.years
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Descent of the last magnet, 26 April 2007
30’000 km underground at 2 km/h!
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Dipole-dipole interconnect
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Dipole-dipole interconnect: electrical splices
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Magnet interconnections
General Advancement of Interconnects per Sector 16-July-2007
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50%
60%
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90%
100%
sector 1-2 sector 2-3 sector 3-4 sector 4-5 sector 5-6 sector 6-7 sector 7-8 sector 8-1
Close W & Jumper
Weld Package I & VAC tests
N-Line Package
Cryo-Lines Welding &Testing
Electrical Interconnects &QA per halfcell
IC preparation
L. Evans – EDMS document no. 859415 11
Global pressure test of Sector 4-5, 12 May 2007
L. Evans – EDMS document no. 859415 12
Flushing machine - Wk 2 January 07
Before
After
Kapton bits
Metal strips
≈ 50 h
+ 8 L of Water
L. Evans – EDMS document no. 859415 13
Q1.R8
L. Evans – EDMS document no. 859415 14
Cooldown of Sector 7-8
From RT to 80K precooling with LN2. 1200 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. 4700 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. 859415 15
600 kW precooling to 80 K with LN2 (up to ~5 tons/h)
Large helium refrigerator for cooling down to 4.5 K
33 kW @ 50 K to 75 K 23 kW @ 4.6 K to 20 K 41 g/s liquefaction
L. Evans – EDMS document no. 859415 16
First cool-down of Sector 7-8
LHC sector 78 - First cooldown
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Time (UTC)
Tem
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K)
Supply temperature Magnet temperature (average over sector)
Return temperature Thermal shields temp. (average over sector)
Active cooling in all thermal shields and
cryogenic tranfer lines. All magnets isolated.
Thermal shield
temp.
Supply
temperature
Return
temperature
Magnet
temp.
Re-start of active cooling for cryogenic
transfer lines
Re-start of active cooling for magnets
Active cooling in all thermal shields and
cryogenic tranfer lines. All magnets isolated.
L. Evans – EDMS document no. 859415 17
120 g/s GHe from 15 mbar with 4 stages
Hydrodynamic cold compressors for 1.8 K refrigeration
L. Evans – EDMS document no. 859415 18
Magnet temperature profile along Sector 7-8 during final cool down to He II
First cool-down of Sector 7-8
L. Evans – EDMS document no. 859415 19
Sector 7-8 Cooldown
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First powering of main quadrupoles
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Cool-Down until Saturday 14-7-7Cool-Down Speed
Avg. Cold Mass Temperature
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Date
T c
m [
K]
planned [K] measured [K] data S7-8 [K]
L. Evans – EDMS document no. 859415 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. 859415 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. 859415 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
Global pressure test &Consolidation
Cool-down
Powering Tests
General schedule Baseline rev. 4.0
L. Evans – EDMS document no. 859415 25
European Strategy Group (1/2)
Consolidation and upgrade of
injectors
LHC upgrade and maximum performance
injectors
[Quotes from the official statement – July 14, 2006]
L. Evans – EDMS document no. 859415 26
R & D for LHC upgrade and facility
preparation for facility
European Strategy Group (2/2)
[Quotes from the official statement – July 14, 2006]
L. Evans – EDMS document no. 859415 27
CERN accelerator complex
L. Evans – EDMS document no. 859415 28
Upgrade procedure
parameters icrelativist classical :
raccelerato theof radiusmean :
emittances e transversnormalized :
nchprotons/bu ofnumber :with
,
2,
R
N
RNQ
YX
b
YX
bSC
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 SLHCneed for new accelerators designed for the needs of SLHC
2. Main performance limitation:
Excessive incoherent space chargetune spreads QSC at injection in thePSB (50 MeV) and PS (1.4 GeV) becauseof the high required beam brightness N/*.
need to increase the injection energy in the synchrotronsneed 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. 859415 29
Upgrade components
PSB
SPSSPS+
Linac4
LPSPL
PS
LHC / SLHC DLHC
Out
put e
nerg
y
160 MeV
1.4 GeV4 GeV
26 GeV50 GeV
450 GeV1 TeV
7 TeV~ 14 TeV
Linac250 MeV
LPSPL: Low PowerSuperconducting 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 1035 cm-2s-1)
DLHC: “Double energy” LHC(1 to ~14 TeV)
Proton flux / Beam power
PS2
PSB
SPSSPS+
Linac4
LPSPL
PS
LHC / SLHC DLHC
Out
put e
nerg
y
160 MeV
1.4 GeV4 GeV
26 GeV50 GeV
450 GeV1 TeV
7 TeV~ 14 TeV
Linac250 MeV
LPSPL: Low PowerSuperconducting 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 1035 cm-2s-1)
DLHC: “Double energy” LHC(1 to ~14 TeV)
Proton flux / Beam power
PS2
L. Evans – EDMS document no. 859415 30
Layout of the new injectors
SPS
PS2
SPL
Linac4
PS
L. Evans – EDMS document no. 859415 31
accelerating accelerating tunneltunnel
accelerating accelerating tunneltunnel
klystron hall (above klystron hall (above ground)ground)
klystron hall (above klystron hall (above ground)ground)
HH-- source & RFQ source & RFQHH-- source & RFQ source & RFQ
Linac4 building and infrastructure
L. Evans – EDMS document no. 859415 32
Linac4 and SPL buildings
Linac4 tunnelLinac4 tunnelLinac4 tunnelLinac4 tunnel
SPL SPL klystron klystron gallerygallery
SPL SPL klystron klystron gallerygallery
SPL tunnelSPL tunnelSPL tunnelSPL tunnel Linac4 klystron Linac4 klystron hallhall
Linac4 klystron Linac4 klystron hallhall
L. Evans – EDMS document no. 859415 33
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 1.0 1014
Transverse emittance (source) 0.2 mm mrad
Transverse emittance (linac) 0.4 mm mrad
Stage 1: Linac4 (1/3)
Linac4 beam characteristics
L. Evans – EDMS document no. 859415 34
Linac4 structures
HH- - sourcesource RFQRFQ choppchopperer DTLDTL CCDTLCCDTL PIMSPIMS
3 MeV 50 MeV 102 MeV
352.2 MHz
160 MeV
Stage 1: Linac4 (2/3)
L. Evans – EDMS document no. 859415 35
Stage 1: Linac4 (3/3)
Direct benefits of the new linacDirect 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 PSBBenefits 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. 859415 36
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
Stage 22 2’2’
CDR2CDR2 ““LPSPL” for LPSPL” for SPS & LHCSPS & LHC
““SPL”SPL”
Energy (GeV) 3.5 4 5
Beam power (MW) 4 0.19 4 - 8
Rep. frequency (Hz) 50 2 50
Protons/pulse (x 1014) 1.4 1.2 1
Av. Pulse current (mA) 40 20 40
Pulse duration (ms) 0.57 1.9 0.4
Bunch frequency (MHz) 352.2 352.2 352.2
Physical length (m) 430 ~460 535
LPSPL and SPL beam characteristics
Stage 2: LPSPL + PS2 (1/3)
L. Evans – EDMS document no. 859415 37
PS2PS2 PSPS
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
Stage 2: LPSPL + PS2 (2/3)
PS2 beam characteristics
L. Evans – EDMS document no. 859415 38
Direct benefits of the LPSPL + PS2Direct 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 PS2Benefits 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
Stage 2: LPSPL + PS2 (3/3)
L. Evans – EDMS document no. 859415 39
Upgrade the LPSPL into an SPL (multi- MW beam power at 2-5 GeV):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 usersPossible users
EURISOL (2EURISOL (2ndnd generation ISOL-type RIB facility) 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 -unstable isotopes to a -beam facility…
Neutrino factoryNeutrino factory=> energy upgrade to 5 GeV (+70 m of sc accelerating structures)
=> 2 fixed energy rings for protons (accumulator & compressor)
=> accelerator complex with target, capture-cooling-acceleration (20-50 GeV) and storage
Stage 2’: SPL
L. Evans – EDMS document no. 859415 40
CDR 2
Planning …
Linac4 approval
3 MeV test place ready
SPL & PS2 approvalStart for Physics