LHC Sector Test

1
LHC Sector Test

• Mike Lamont

2
Outline

• Overview
• Motivation
• Pre-requisites/preparation
• Tests with beam
• Organisation
• Conclusions

3
Overview

• TI8 injection L8 LHCb - arc 7-8 IR7
• 2 weeks with beam
• Close sectors 8-1, 7-8 and 6-7
• Beam
• Pilot Beam for the most part
• single bunch of 5 - 10 x 109 protons
• Total intensity
• 3 x 1013 protons - comparable with one nominal
  intensity LHC extraction from the SPS

4
Injection
5
Triplets LHCb
Aiming for minimal losses in LHCb
6
Sector 7-8
X 23
7
IR7 layout

1. Intercept the beam with the three TCPs and with
   the TCSGs
2. Invert the polarity of D3
3. Switch OFF all the quadrupoles

Stefano Raedelli Ralph Assmann
8
Intercepting the beam with the TCPs
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IR7

• Three TCPs closed smartly, D3 in opposite
  polarity, quadrupoles off
• All beam particles interact with gt1m of C
  (typical1.8m max3m)
• Additional protection from the next secondary
  collimators
• EM showers are expected to be absorbed by MBW and
  MQW yokes (no issues for magnet). Detailed
  estimates should confirm that.
• Minimum impact on the machine - D3 polarity
  change (cable). - Lock collimators in position
  - Local activation - simulations to be
  performed.

10
Motivation
11
Integration

• Full test of a majority of subsystems over more
  than one eighth of the ring
• Allows staged approach to the full problem space
• Time to fully resolve problems before the real
  thing
• Analysis, improvements, resolution, adjustment
• The lessons learnt will reduce the time needed
  for full commissioning

Buys breathing space if there are any serious
problems
12
Integration commission with beam
Full-blown system wide integration test
13
Beam the ultimate diagnostic

• Polarity of magnetic elements
• Aperture in the cold machine
• Response of key beam instrumentation
• Magnet field quality

"What like a bullet can undeceive?" Herman
Melville
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Milestone

• Machine Protection
• Controls
• Magnets (model etc.)
• Beam Instrumentation
• BT Kickers, Septa, TDI
• Collimation
• Radiation Protection
• Access
• Operations
• Hardware Commissioning

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Required circuits
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IR8
RQ5.R8 Q5 quadrupole
RQ4.R8 Q4 quadrupole
RD2.R8 D2 recombination dipole
RD1.R8 D1 recombination dipole
RQX.R8 Inner triplet
RQX.L8 Inner triplet
RD1.L8 D1 recombination dipole
RD2.L8 D2 recombination dipole
RQ4.L8 Q4 quadrupole
RQ5.L8 Q5 quadrupole
RQ6.L8 MQM MQML
Plus dipole correctors
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DS left IP8
RQ7.L8 2MQM
RQ8.L8 MQML
RQ9.L8 MQM MQMC
RQ10.L8 MQML
RQTL11.L8B2 MQTLI
RQT12.L8B2 MQT
RQT13.L8B2 MQT
Plus dipole correctors

• Item Two lips, indifferent red
• Item Two grey eyes with lids to them
• Item One neck, one chin, and so forth.

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Arc 7-8
Circuits Number of circuits Priority
Main bends MB RB.A78 1 1
Main quads MQ RQF, RQD 2 1
Skew quads MQS RQS B2 1 1
Trim quads MQT RQTF,RQTD B2 2 1
Orbit correctors MCB RCB B2 23 H 24 V 1
Lattice sextupoles MS RSF,RSD B2 4 2
Lattice octupoles MO ROD, ROF B2 1 3
Skew sextupoles MSS RSS B2 1 3
b3 spool MCS RCS B2 1 3
b4 spool MCO RCO B2 1 3
b5 spool MCD RCD B2 1 3
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DS/LSS - right of 7
RQT13.R7B2 QT
RQT12.R7B2 QT
RQTL11.R7B2 QTLI
RQTL10.R7B2 QTLI
RQTL9.R7B2 QTLI
RQTL8.R7B2 QTLI
RQTL7.R7B2 QTLI
RQ6.R7B2 6 QTLH
Q7,Q8,Q10,Q11 one MQTL alongside the MQ
quadrupole Q9 two MQTLs
Plus dipole correctors
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Required circuits

• To get beam through sector 78, the main circuits
  listed above are required to be commissioned to
  450 GeV.
• For limited recycling, it would be preferable for
  listed circuits to be available to, say, the
  equivalent 1 TeV level.

• Beam 2 Circuits only
• Circuits commissioned to 450 GeV only

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Other systems

• Injection elements septa, kickers
• Collimators
• Machine Protection
• Beam Instrumentation
• BPMs, BLMs, BTV, BCT, BST
• Magnet Model
• Transfer functions, harmonics
• Controls
• Software/tools
• Access system
• Radiation Protection
• Radiation Monitoring
• Optics, aperture model

Sector Test is another progressive milestone to
be used for testing key functionality
Work in progress but most of this is in good
shape. Effort in these areas is essentially
orthogonal to HWC.
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Access

• Sector 6-7.
• Interlocked gate right of IP 6
• Point 7 (PM76)
• Access system operational.
• Point 8 (PM85)
• Access point fully operational.
• PZ85
• Interlocked door in shielding wall
• Sector 1-8
• Interlocked gate left of IP 1

Final Configuration
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Radiation Protection

• All major installation will have finished and
  access to the zones affected after the test will
  be limited.
• Dose maps for collimators in IR7 to be carefully
  evaluated.
• Given analysis, and measurements during and after
  the test, it is envisaged that
• Certain areas might be declared controlled areas
  for the first few days after the test
• Thereafter these areas would join the rest of the
  sectors involved as supervised areas
• LHCb remains an undesignated area
• Traceability restrictions come into force
• Need for additional RP instrumentation to be
  evaluated.

Work in progress. NB amount of beam is minimal.
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Beam
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1. Commission injection region

• Steer into ring, onto TDI
• Check instrumentation, septa, kickers, aperture

Jan Uythoven
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2. Thread to IR7

• Commission trajectory acquisition and correction
• Thread beam

Jorg Wenninger
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3. Linear optics measurements

• Trajectory response using correctors and BPMs
• BPM corrector polarity and calibration errors
• Phase, coupling
• Dispersion measurement with dp and BPMs
• Betatron matching measurement with BTVs

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4. BLM system tests

• Get the system up and running, recording losses
• Prior calibration with source expect reasonable
  numbers
• Acquisition display of beam losses
• Some crosstalk studies possible (in principle
  beam 1 monitors available)

Bernd Dehning
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5. Aperture measurement

• First iteration oscillation from 2 correctors
  at 90º to probe all phases
• Second iteration if needed/time p bumps (local
  anomalies, specific regions)

Brennan Goddard
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6. Momentum Aperture

• Transmission vs momentum offset by changing SPS
  RF frequency
• Re-scale TI 8 to new momentum

dp/p 0.004 (1mm en)
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7. Field quality checks

• Kick-response and trajectory analysis
• LOCO might be able to get a handle on average
  a2, b2 and b3 field errors of MBs, b2 of MQs
• Possibly extend method to check multipole
  corrector polarities (possibly via strong
  excitation))

Jorg Wenninger
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8. Effects of magnetic cycle

• Machine reproducibility and persistent current
  effects at injection for reduced pre-cycle

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9. Quench limits and BLM response
Quenches with beam motivation - safe and
efficient operation - avoid quenches and damage
Controlled, well defined tests to
establish Absolute quench limits BLM threshold
values Model and understanding of correlation of
loss pattern, quench level, BLM signals
Test important for efficient commissioning of BLM
system with circulating beam
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Other possibilities

• 10. Energy offset versus time on flat bottom
• 11. Transfer line collimation studies
• 12. Injection projection studies
• 13. Separation and crossing angle bumps
• Injecting onto vertical separation bump
• Bump closure, induced dispersion, aperture
• 14. Commission multi-bunch injection

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Beam tests - summary
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Near test schedule
Phase Time
Sector checkout, interlock machine protection tests etc. Tstart - 2 weeks
Close sectors 6-7, 7-8, 8-1 Tstart 3 day
Access system tests qualification Tstart 2 day
Beam to end TI8 Tstart 1 day
Tests with beam 2 weeks
Radiation survey Tend 1 day
Establish supervised areas Tend 2 day
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Schedule
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Impact 1/2

• Given the state of installation, the sector test
  should have minimal impact on transport,
  interconnection work etc.
• Deliberately chosen solution in IR7 which avoids
  additional interventions
• Restricted access to sectors 8-1, 7-8, 6-7 during
  beam tests 14 days
• 7-8 and injection region part of 8-1 become
  supervised areas after test (film badge etc.)
• Work/Commissioning can clearly continue in other
  sectors during the test

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Impact 2/2

• Sector test makes clear demands on
• what is needed to be cold
• on what is needed to be hardware commissioned
• and to what level
• Cryogenics, QPS, HWC support required during test
• Could take time out of HWC program
• HWC would have to stop in 7-8 during test
• Test preparation, other than cold mass, largely
  orthogonal to HWC

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Details
Chamonix 2006
Sector test with beam
Overview, motivation and scheduling Mike Lamont
Proposed tests with beam Brennan Goddard
Magnet quenches with beam Alex Koschik
Beam Instrumentation Lars Jensen
Magnet requirements Luca Bottura
Controls requirements Robin Lauckner
Sector test preparation Chair Pierre Strubin
Planning Esther Barbero Soto
Global Hardware Status Miguel Jimenez
Layout in LSS7 Jan Uythoven
Hardware Commissioning Roberto Saban
State of LHCb for the test Massimiliano Ferro-Luzzi
Radiation Issues Helmut Vincke
Access system Pierre Ninin
Team in place which is examining implications,
requirements and details of planned beam tests
http//cern.ch/lhc-injection-test/
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Conclusions

• A sector test is surely a very useful exercise
• Undoubtedly speed full commissioning
• It could prove to be a vital exercise
• If any major problems are uncovered
• Requirements have clearly stated and are being
  addressed
• Planned beam tests have been detailed
• The potential impact would be minimal.
• Machine as is or as will be. Work carries on
  elsewhere.
• However, for the test to take place this year (if
  the schedule allows) Hardware Commissioning would
  have to be tailored to provide necessary circuits
  to the necessary level.

42
Acknowledgements

• Magnets Luca Bottura
• Beam Instrumentation Rhodri Jones, Lars Jensen,
  Stephen Jackson
• Injection Brennan Goddard, Jan Uythoven
• Radiation Protection Doris Forkel-Wirth, Helmut
  Vincke
• INB Ghislain Roy
• Access Pierre Ninin
• LHCb Rolf Linder
• HWC Roberto Saban team
• Installation Katy Foraz
• Planning Esther Barbero Soto
• Vacuum Paul Cruikshank, Miguel Jimenez
• Controls Robin Lauckner
• OP/AP Roger Bailey, Verena Kain, Massimo
  Giovannozzi, Stephane Fartoukh, Helmut
  Burkhardt, Alex Koshick, Stefano Raedelli,
  Ralph Assmann, Frank Zimmerman and the rest
  of the commissioning team.