Transcript CM13-OB-V1.ppt

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
CM13 in Port Jefferson; 4. to 6. November 2009
Oliver Brüning/CERN AB-ABP
0
•
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
•
Additional local
dissipation [W]
Machine wide investigations at cold Q4 2008
15
10
5
y = 9.2E-08x2.0E+00
0
0
Fix anything obviously very wrong (means
warming up)
5000
10000
Dipole current [A]
Sector A12: A15R1 – C19R1: Dipole Measurements made on 03.11.08
Q4 2008
12
Cold
23
< 100K
34
Warm
45
< 100K
56
Cold
67
Cold
78
Cold
81
Cold
B16R1 => 2334
0.7mV/7kA=100nOhm
0.7mV*7kA=4.9W
Snapshot at 03.09.08 : 0.85mV*8.4kA=7.1W
05/11/2008
Zinour Charifoulline, AT/MEI
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
Calorimetric & electrical measurement summary
35
# of sub-sectors [-]
30
25
20
Made wherever possible in late 2008
Sectors 23 34 45 already not cold
Sectors 12 56 67 78 81 measured
Identified 3 suspicious cases (in magnets)
Sector 12 – 15R1 – confirmed
Sector 12 – 31R1 – not confirmed
Sector 67 – 31R6 – confirmed
15
10
5
S34
0
-50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100110120130140150160170180190200
Sub-sector resistance variation w/r to baseline [nW]
Decisions Q1 2009
Sector 34 repair
Q4 2008
Q1 2009
Restart
Q2 2009
Q3 2009
Q4 2009
• Decided to warm up in 12 and 67 to replace faulty magnets
• Decided to warm up sector 56 in parallel for other reasons
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
• Warming up means
–
–
–
–
3 weeks to get to 300K
Repair work
ELQA and other issues
6 weeks to get back to 2K
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
Sector 34 repair
Q4 2008
Q1 2009
Q2 2009
Restart
Q3 2009
Q4 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
Measurement summary Q3 2009
• 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
8/6/2016
8
Energy
• 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
8/6/2016
9
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
8/6/2016
11
SD2: Conditions
for working at height
Access to ALICE
subject to conditions
SD1: Conditions
for working at height
Access to ATLAS
subject to conditions
SMI2: Conditions
for working at height
27th May 2009
12
Readiness of the sectors, late October
Sector 12
PO Phase II
Sector 23
PO Phase II
Sector 34
Cryo tuning
Cool down
PO Phase I
Sector 45
8/6/2016
Sector 56
PO Phase II
Sector 67
PO Phase I
Sector 78
PO Phase II
Sector 81
PO Phase II
13
Revised target for 2009
8/6/2016
14
First lead ions in LHC
23.-25. October
Injection region
screens
Mike Lamont
TI2/S23 – first trajectory
TI2
IT09
S23
15
27-10-09
Trajectory difference before/after precycle
IP2
IP3
Reproducibility looks very good
IT09
16
27-10-09
Injection region aperture
Mode
l
Measured
IT09
Brennan
Goddard
17
27-10-09
Injection region trajectories through arc
IR3
IR2
IT09
18
27-10-09
First beam to point 7
TI8
S78
In the
aperture
model
IT09
19
27-10-09
Dispersion TI8/S78
Measured
v. model
TI8
S78
Normalize
d
IT09
20
27-10-09
Kick response
IP3
IP2
Problem?
Beam
Green – Measured
Purple - model
IT09
21
27-10-09
Sunday – Walter starts early…
Collimator scan
H
Non-closure of LHCb dipole and
compensators with LHCb dipole at
full field (rms ~ 1 mm)
V
IT09
Beam
22
27-10-09
Aperture
IT09
23
27-10-09
Proton commissioning (as planned since 2005)
(A)
2009
Repair of Sector 34
Installation of protection systems
Hardware commissioning
Machine
checkout
No beam
A
2010
Beam
commissioning
Beam
B
43/156 bunch operation
50ns operation
Beam
25ns
operation
?
Shutdown
No beam
Targets with beam 2009
Do this with safe beams
1012 at 450 GeV → 2 1011 at 1.1 TeV,
3 1010 at 3.5TeV
LIMIT
2 on 2 with 5 1010 per bunch at 1.1 TeV
2 on 2 with 1010 per bunch at 3.5TeV
Christmas break
• 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