RF-Experiments Synchronization Meeting
→
Europe/Zurich
4-R-017 (CERN)
4-R-017
CERN
Description
Dedicated Timing meeting to take stock of what we learned during LHC startup and prepare the restart. In particular:
*understand the BPTX and Vertex results of 2009 in relation to RF events,
*from this experience, decide what is the acceptable range (both from RF and experiments) of Vertex and BPTX variations without requiring a warning and/or a rephasing. Or, in other terms, what is a 'wrong' phase, from both RF and experiments points of view.
*define a procedure for 2010 runs (phase alignment, piquet service, system monitoring)
AGENDA:
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A. from 2009:
A.1. Feedback from RF point of view
*A.1.a. Summary of RF phase jumps & explanation
*A.1.b. Vertex position shift versus RF events
*A.1.c. sigma-z variation- impact on vertex position?
*A.1.d. Phase during ramp
*A.1.e. Clock quality and stability in Nov & December at the CCR (jitter, jumps…)
*A.1.f. Conclusion: what should we expect as ‘normal’ variations of bunches & beam spot from RF point of view?
A.2. Feedback from experiments
*A.2.a. consistency of BPTX deltaT versus Vertex? Resolution of BPTX measurements after calibration?
*A.2.b. How do experiments deal for deltaT with multibunching?
*A.2.c. Which shift in beam spot position can experiments tolerate without requiring rephasing?
*A.2.d. Is there an impact of RF BC variations on the vertex reconstruction?
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B. for 2010:
B.1. External clock handshake? Except during SETUP (and before IMMINENT), when may resynchro happen?
B.2. No synchronised Bcref for 2010 – check the agreement from experiments
B.3. Rephasing procedure for 2010:
*B.3.a. Will we use the BPTX to check the alignment? Should/could the data be published? Which format?
*B.3.b. Will the RF implement this automatic rephasing tool?
*B.3.c. If the phase is 'wrong', what should be the procedure? (experts won’t be there night and day on a long term basis)
*B.3.d. If rephasing is done, could it be during ‘stable beam’? If yes, will the feedback be given by vertex reconstruction? How fast is it (versus luminosity)?
B.4. RF Piquet
*B.4.a. Procedure for experiments to follow before calling the Piquet service. Is it through CCC?
*B.4.b. Requirements of registers publication on DIP for RF-Rx configuration check
B.5. Fibre maintenance:
*B.5.a. EN-EL proposal
B.6. Drift versus temperature of transmitted RF signals