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LHC Status / View From CERN. Understanding the LHC Interconnects. (Roger Bailey). Status Hardware Commissioning:. nQPS installation Cool down Access matrix and phased powering Schedule. Sector tests. (Mike Lamont). Commissioning plans for 2009. - PowerPoint PPT Presentation
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LHC Status / View From CERN
Status Hardware Commissioning:
nQPS installation
Cool down
Access matrix and phased powering
Schedule
CM13 in Port Jefferson; 4. to 6. November 2009 Oliver Brüning/CERN AB-ABP 0
Sector tests
Commissioning plans for 2009
Understanding the LHC Interconnects (Roger Bailey)
(Mike Lamont)
Machine wide investigations at cold Q4 2008
• Controlled calorimetric measurements at cold where possible
– Measured heat loads indicated problem areas• Measure electrical resistance in suspect
regions– Electrical resistance of joints between and inside
magnets
• Fix anything obviously very wrong (means warming up)
y = 9.2E-08x2.0E+00
0
5
10
15
0 5000 10000
Addi
tiona
l loc
al
diss
ipati
on [W
]
Dipole current [A]
Sector A12: A15R1 – C19R1: Dipole Measurements made on 03.11.08
0.7mV/7kA=100nOhm0.7mV*7kA=4.9W
Snapshot at 03.09.08 : 0.85mV*8.4kA=7.1W
B16R1 => 2334
05/11/2008 Zinour Charifoulline, AT/MEI
Q4 2008
12 Cold
23 < 100K
34 Warm
45 < 100K
56 Cold
67 Cold
78 Cold
81 Cold
Investigations in sector 34 Q1 2009
Bad surprise after gamma-ray imaging of the joints Void is present in bus extremities because SnAg flowed out during soldering of the joint
0
5
10
15
20
25
30
35
-50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200
# of
sub-
sect
ors [
-]
Sub-sector resistance variation w/r to baseline [nW]
Calorimetric & electrical measurement summary
Made wherever possible in late 2008Made wherever possible in late 2008Sectors 23 34 45 already not coldSectors 23 34 45 already not coldSectors 12 56 67 78 81 measuredSectors 12 56 67 78 81 measured
Identified 3 suspicious cases (Identified 3 suspicious cases (in magnetsin magnets))Sector 12 – 15R1 – confirmedSector 12 – 15R1 – confirmedSector 12 – 31R1 – not confirmedSector 12 – 31R1 – not confirmedSector 67 – 31R6 – confirmedSector 67 – 31R6 – confirmed
S34
Decisions Q1 2009
• Decided to warm up in 12 and 67 to replace faulty magnets • Decided to warm up sector 56 in parallel for other reasons
• Warming up means– 3 weeks to get to 300K– Repair work– ELQA and other issues– 6 weeks to get back to 2K
Q4 2008 Q1 2009
12 Cold Cold Warm
23 < 100K < 100K
34 Warm Warm
45 < 100K < 100K
56 Cold Cold Warm
67 Cold Cold Warm
78 Cold < 100K
81 Cold < 100K
Q4 2008 Q1 2009 Q2 2009 Q3 2009 Q4 2009
Sector 34 repair Restart
Machine wide investigations Q2 2009• Electrical measurements at warm on sectors 12 34 56 67• Confirms new problem with the copper stabilizers
– Non-invasive electrical measurements to show suspicious regions• Several bad regions found
– Open and make precise local electrical measurements • Several bad stabilizers found (30µΩ to 50µΩ) and fixed
• Measured other 4 sectors at 80K (noisy but gives limits)
Machine wide activities Q4 2008 and 2009
– Electrical splice measurements everywhere at cold (measuring nΩ) Q4 2008• Had to warm up sectors 12 56 67
– Electrical stabilizer measurements everywhere at warm or at 80K (measuring µΩ) Q1 Q2 2009• Had to warm up sector 45
– Major new protection system based on electrical measurements Q1 – Q4 2009 (nQPS)– Pressure relief valves installed everywhere possible Q1 – Q3 2009 (dipoles have to be warm)– Reinforcement of floor anchors everywhere Q1 – Q3 2009
Q4 2008 Q1 2009 Q2 2009 Q3 2009 Q4 2009
12 Cold Cold Warm Warm Warm Cold Cold
23 < 100K < 100K < 100K Cold Cold 80K Cold Cold
34 Warm Warm Warm Warm Cold Cold
45 < 100K < 100K 80K Warm Warm Cold Cold
56 Cold Cold Warm Warm Warm Cold Cold
67 Cold Cold Warm Warm Warm Cold Cold
78 Cold < 100K < 100K 80K 80K Cold Cold
81 Cold < 100K < 100K 80K 80K Cold Cold
Q4 2008 Q1 2009 Q2 2009 Q3 2009 Q4 2009
Sector 34 repair Restart
• 5 sectors measured at cold for splices– 12 56 67 78 81
• Nothing above 40 nΩ remaining
– 23 34 45 not measured• Data mining finds nothing > 25 nΩ (in 99% of 23 34 45)
• 5 sectors measured at warm for stabilizers– 12 34 45 56 67
• All above 50µΩ fixed
– 23 78 81 measured at 80K• Nothing above 90µΩ remaining
04/21/23 8
Measurement summary Q3 2009
• Putting all this together– Splices
• 5 TeV OK
– Stabilizers• 3.5 TeV OK• Higher energies needs operational experience to see which model
variant most closely matches reality• 90µΩ limit is very conservative
– Start at 3.5 TeV– Operate– Move to 5 TeV when experience allows it
04/21/23 9
Energy
Quench Protection System upgrade (nQPS)
• New QPS to provide– Protection against symmetric quenches (problem noticed in summer 08)– Local bus bar measurements capable of detecting bad splices
• Will also provide– Precision measurements of the joint resistances at cold (sub-nΩ range) of every busbar
segment• complete mapping of the splice resistances (the bonding between the superconducting
cables)– The basic monitoring system for future determination of busbar resistances at warm
(min. 80 K)• measure regularly the continuity of the copper stabilizers
• Huge task– Has to be working before repowering (recommendation of external review)– On the critical path for restart– Requires extensive testing
LHC Enhanced Quench Protection System Review
Cool down 2009
04/21/23 11
12122727thth May 2009 May 2009
Access to ALICE subject to conditions
SD2: Conditions for working at height
SMI2: Conditions for working at height
Access to ATLAS subject to conditions
SD1: Conditions for working at height
Readiness of the sectors, late October
04/21/23 13
Sector 12 PO Phase II
Sector 23 PO Phase II
Sector 34 Cryo tuning
Sector 45 PO Phase I
Sector 56 PO Phase II
Sector 67 PO Phase I
Sector 78 PO Phase II
Sector 81 PO Phase II
Cool down
Revised target for 2009
04/21/23 14
First lead ions in LHC
IT09 15 27-10-09
Injection region screens
TI2/S23 – first trajectory
TI2 S23
23.-25. October
Mike Lamont
Trajectory difference before/after precycle
IT09 16 27-10-09
IP2 IP3
Reproducibility looks very good
Injection region aperture
IT09 17 27-10-09
Model
Measured
BrennanGoddard
Injection region trajectories through arc
IT09 18 27-10-09
IR2
IR3
First beam to point 7
IT09 19 27-10-09
TI8 S78
In the aperture model
Dispersion TI8/S78
IT09 20 27-10-09
TI8 S78
Normalized
Measured v. model
Kick response
IT09 21 27-10-09
Beam
Green – MeasuredPurple - model
IP2IP3
Problem?
Sunday – Walter starts early…
IT09 22 27-10-09
Non-closure of LHCb dipole and compensators with LHCb dipole at
full field (rms ~ 1 mm)
Beam
H
V
Collimator scan
Aperture
IT09 23 27-10-09
Proton commissioning (as planned since 2005)
Repair of Sector 34
Installation of protection systems
Hardware commissioning
Machine checkout
Beam commissioning
No beam Beam
2009
No beamBeam
43/156 bunch operation 50ns operation25ns
operation ?
Shutdown2010
(A)
A B
Targets with beam 2009
Do this with safe beams
1012 at 450 GeV → 2 1011 at 1.1 TeV, 3 1010 at 3.5TeV
LIMIT2 on 2 with 5 1010 per bunch at 1.1 TeV
2 on 2 with 1010 per bunch at 3.5TeV
• Stop LHC with beam – ~17th December 2009, restart ~ 7th January 2010
• Cryogenics:– 2 days to set-up 3 K for Christmas– 3 days on return to re-establish 1.9 K– Coverage over stop - details to be finalized
• All machines on standby except for– Essential maintenance work on LHC will be performed
during the stop– Essential maintenance work on injectors will be performed
during the stop
Christmas break