results from beam-based collimator alignment
DESCRIPTION
Results from Beam-Based Collimator Alignment. G. Valentino, R. W. Assmann , R. Bruce, F. Burkart , M. Cauchi , D. Deboy , L. Lari , S. Redaelli , B. Salvachua. Outline. The collimator s etup a pplication Fast BLM data acquisition - PowerPoint PPT PresentationTRANSCRIPT
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LHC Collimation Working Group – 02 April 2012
Results from Beam-Based Collimator Alignment
G. Valentino, R. W. Assmann, R. Bruce, F. Burkart, M. Cauchi, D. Deboy, L. Lari,
S. Redaelli, B. Salvachua
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Outline
Gianluca Valentino
2
• The collimator setup application
• Fast BLM data acquisition • Software issues encountered during the setups
• Results comparison: 2011 vs. 2012
• Qualification of the collimator settings
• Summary
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Reminder: collimator setup application
Gianluca Valentino
3
Setup Task Sequencer
GUI
User
Parallel Setup Algorithm
Loss Threshold Selection
BLM Spike Recognition
Fast BLM Data Acquisition
BLM Feedback
Structure as proposed for March 2012 setups
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12.5 Hz BLM data acquisition
Gianluca Valentino
4
cs-ccr-logging2
cs-ccr-dev
Thanks to: R. Assmann, V. Baggiolini, A. Bland, B. Dehning, S. Jackson, S. Redaelli, C. Zamantzas
CCC Setup Application
Fast BLM Data Logging
~3900 BLMs in all crates
12.5 Hz and 1 Hz BLM signals
Left jaw aligned
Right jaw aligned
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Issues encountered during setups
• Some software issues were encountered in the 450 GeV setup, which were fixed by the 4 TeV setup:
- Fast BLM data was transmitted from the low-level with channels & crates in reverse order for each IR.
- GUI: multi-threading issues prevented full functionality of GUI.
- Sequencer not jumping correctly through the setup stages (TCP, parallel, sequential).
- Setup Sheet: left and right jaw positions not saved correctly.
• Outstanding issues:
- Loss spike recognition: All clearly optimal spikes (e.g. TCP IR7) were classified correctly.
- Main issues were for “grey area” spikes: in the classifier design, it was preferred to err in classifying an optimal spike as non-optimal rather than classifying an non-optimal spike as optimal.
- When detecting a non-optimal spike, the jaw is moved in once again until an optimal spike is classified. This could cause dumps at 4 TeV if the jaw is at the beam and is moved in erroneously again.
- Algorithm assumes a simple loss spike model with a low noise level, no other spikes after main spike, etc.
- An improved spike recognition algorithm will be developed and tested in an MD.
• Beam instabilities: possible impedance effects with too many collimators close to the beam (N. Mounet)
Gianluca Valentino
5
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Alignment results: setup time
• Setups in March 2012:
• Comparison in setup time 2010 – 2012 for the full system:
Gianluca Valentino
6
2010 (Manual) 2011 @ 1 Hz 2012 @ 8 Hz
450 GeV 3.5 TeV 450 GeV 3.5 TeV 450 GeV 4 TeV
# Fills 3 5 6 3 3 1
# Dumps 1 4 2 0 0 0
# Hours 11 28 18.5 17.7 10 7.5
Setup Type Injection Flat Top Colliding Squeezed
Date 21st March 29th March 30th March 31st March
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Alignment results: beam-based centres
• Beam-based centre comparison to 2011 for injection orbit.
Gianluca Valentino
7
µ = 0.177 mm σ = 0.033 mm
µ = 0.229 mmσ = 0.076
mm
Delta: 450 GeV 2011 vs. 2012 B1 and B2 Delta: Flat Top 2011 vs. 2012 B1 and B2
∆ TCLIA.4R2 = -12.920mm∆ TDI.4L2 = +7.048mm
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Alignment results: beam-based centres
Gianluca Valentino
8
µ = 0.238 mmσ = 0.111
mm
µ = 0.183 mmσ = 0.059 mm
• Beam-based centre comparison between 450 GeV and 4 TeV in 2012 (injection orbit).
Delta: 450 GeV vs. 4 TeV B1 Delta: 450 GeV vs. 4 TeV B2
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Alignment Results: Beam Size Ratios
• Beam Size Ratio comparison: 2012 vs 2011, 450 GeV
Gianluca Valentino
9
IR2 IR3 IR7 IR8 IR3IR7
TDI TDI
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Alignment Results: Beam Size Ratios
• Beam Size Ratio comparison: 2012 vs 2011, Flat Top
Gianluca Valentino
10
IR3 IR7 IR3IR7
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Collimator Settings Qualification
Gianluca Valentino
11
B. Salvachua
LIC BLMs
LIC BLMs
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Collimator Settings Qualification
Gianluca Valentino
12
B. Salvachua
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Summary
• Collimator setup time reduced from 17 hours in 2011 to 7.5 hours in
2012 at flat top, 1 fill.
• Limit for setup time not yet reached: improvements can still be made.
• Further tests will be carried out in an 8 hour slot in April MD.
Future Work:
• Only GUI will run on CCC console: BLM feedback and jaw movement
requests to be moved to a server.
• Distributed application will be developed based on Java RMI and JMS,
running on the server and the CCC console.
• More complex beam loss recognition system to be designed.
Gianluca Valentino
13