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

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

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

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

04/20/23 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

04/20/23 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

Cool down 2009

04/20/23 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

General Schedule 9th, September 09

Readiness of the sectors, late October

04/20/23 14

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

04/20/23 15

First lead ions in LHC

IT09 16 27-10-09

Injection region screens

TI2/S23 – first trajectory

TI2 S23

23.-25. October

Mike Lamont

Trajectory difference before/after precycle

IT09 17 27-10-09

IP2 IP3

Reproducibility looks very good

Injection region aperture

IT09 18 27-10-09

Model

Measured

BrennanGoddard

Injection region trajectories through arc

IT09 19 27-10-09

IR2

IR3

First beam to point 7

IT09 20 27-10-09

TI8 S78

In the aperture model

Dispersion TI8/S78

IT09 21 27-10-09

TI8 S78

Normalized

Measured v. model

Kick response

IT09 22 27-10-09

Beam

Green – MeasuredPurple - model

IP2IP3

Problem?

Sunday – Walter starts early…

IT09 23 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 24 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