VK, IC, VI, JH, ND; Summary of the ring commissioning meeting #4
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- 300 turns achieved.
- Probably more but limited by libera cut-off frequency.
- Need to measure the injection axis |
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IC, VK, VI (ND); Summary of the ring commissioning meeting #3
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Shift summaries for the ring for last week are at
https://elog.lal.in2p3.fr/THOMX/Commissionning/568
https://elog.lal.in2p3.fr/THOMX/Commissionning/570
https://elog.lal.in2p3.fr/THOMX/Commissionning/571
The
problem with the pulse jumpis with 12ns delays has been identified and fixed (it was related to the synchronisation system).
The main issue identified |
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VK, IC, AM, ND; Summary of the ring commissioning meeting #2
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Slides are at https://indico.ijclab.in2p3.fr/event/8750/
- There is a difference in BPM numbering in Tango and MML => we should stick to Tango names.
- Beam was very unstable during the past week |
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IC, VK, VI, VC, JH, HG, ND; Summary of the ring commissioning meeting #1
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Status slides presented by Iryna available on indico at https://indico.ijclab.in2p3.fr/event/8749/
The beam parameters required for a good injection in the ring were discussed.
The following required parameters were identified: |
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VK, IC, VM, JH, ND; Summary of the ring commissioning meeting
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Discussed recent orbit correction of the expanded orbit.
Need to make run with cavity detuning from its resonant conditions
used in the conditioning.
Discussed measurement of tune, and possible origins of inconsistant/noisy measurements.
Either BPMs signal processing or weak excitation. Beam size?
Need to do measurements with scope, to see if we can interpret TbT |
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VK, IC, VM, JH, KD, ND; Summary of the ring commissioning meeting
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The ring orbit has been re-established despite some difficulties after the shutdown.
The ring cavity has been started. Whatever the phase it kills the beam.
Two hypothesis: |
IC, VK, VM, SC, ND; Summary of the ring commissioning meeting 
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Notes from last week:
Beam was very unstable (probably energy instabilities), lot of time was spent tuning the injector.
Beam instabilities prevented
us from having a good storage.
Unable to start the extraction line dipole.
Comments: |
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VK, VM, SC, ND, HG; Summary of the ring commissioning meeting
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Summary of last week:
- On Thursday the beam energy was very different from usual (magnets current higher 172A for TL; 176A for RI) => made it impossible to re-use
previous settings for the ring and to find new settings. |
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VK,IC, SC, VM, ND; Summary of the ring commissioning meeting
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No beam last week. No beam this week.
Machine recovery on 2/2 => Nicolas may try to tune the machine with students.
Data taking on 9/2 for diags and machine characterization. |
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VM, VK, ND; Summary of the ring commissioning meeting
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This week: beam on Thursday.
So far we did not see any screenshot of Ring variables check.
Looking at last week's data, shot to shot charge instability seems to be > 15% |
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IC, VM, SC, JH, VC, ND; Summary of the ring commissioning meeting
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Excitation (betatron oscillation) on the beam observed by exciting it with the extraction kicker => initial measures of the tune.
Tune measured close from expected value.
Reason for oscillation damping is not understood. |
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IC, VK, VM, JH, ND; Summary of the ring commissioning meeting
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- Went up to 100kV in the cavity once it was tuned.
- Achieved nice storage stable for 2500 turns and some beam for > 100ms
- Measured the tune: several peaks around 0.35[1] (near the expected value) and one peak not understood at 0.5 |
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IC, VK, LS, JH, ND; Summary of the ring commissioning meeting
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=== Summary of last week:
- Frequency was reduced to 500.0202MHz but the beam stayed only for 100s of turns
- Good storage was achieved at 500.40MHz: |
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VK, IC, JH, VM, LS, MB, ND; Summary of the ring commissioning meeting
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Main studies:
- Measure bucket width in phase on Thursday at 500.02MHz => no storage beyond 45kV
- Measure frequency with spectrum analyser => 500.39MHz |
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IC, VK, VM, LS, JH, MB, ND; Summary of the ring commissioning meeting
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Comments:
* There are strong evidences that part of the frequency problem comes from mechanical issue
* Fring field of the dipoles seems to be longer than anticipated. This could lead to shortening of the orbit. |
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IC, VK, VM, LS, JH, SC, ND; Summary of the ring commissioning meeting
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Report from last week:
- Attempted the strategy suggested by Alex
- Comparison of orbit with RF ON and RF OFF helped understand the "natural" frequency of the ring: 500.33MHz |
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VK, IC, LS, ND; Summary of the ring commissioning meeting
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Discussion mécanique
- Tous les dipoles ont été alignés par rapport à des surfaces de référence
- Le décalage du centre magnétique par rapport au centre mécanique a été mesuré par Cynthia et pris |
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ND, IC; Steerers and BPM map for the ring
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| See attached files. |
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ND; Réunion Physique ThomX
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Transparents sur: https://indico.ijclab.in2p3.fr/event/9358/
Quelques notes de la réunion de Physique de ThomX:
- Présentation de Marie sur les mesures dans le linac |
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IC, VK, VI, VC, JH, HG, ND ; Ring objectives
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This entry is to be updated as the work progresses.
1) Re-establish beam transport to ring
2) Scan in time the septum |