Present:
M. Barnes, I. Karpov, O. Bjorkqvist, J. Rideweeod, K. Kodama, L. Jensen, D. Mcfarlane, . Balhan, H. Bartosik, G. Papotti, E. Carlier, C. Pasquino, F. Velotti, B. Goddard, K. Li, V. Kain, E. Shaposhnikova, A. Butterworth
General follow-up:
Agenda:
- ZS recommissioning strategy for the 2021 start up of the SPS (B. Balahan)
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Interlock on stopping extraction when ZS HV off needs to be very carefully checked in commissioning and maybe more regularly (Verena, Bruno)
- anode temperatures to add in logging (Bruno, Francesco)
- spark logging to check, whether correlation with the cycle is possible (Bruno, Francesco)
- BLM interlocking needs consideration with the different running sums (Francesco, Verena)
- Fixed display for CCC needs to be updated? (Bruno, Yannick)
- Alignment optimiser to deploy in an application (Verena)
- Need to prepare what has to be done for the SIS of the voltage, if we need the PPM voltage modulation (Verena, Bruno)
- ZS expert to be present during steps in intensity/# bunches for the LHC beam intensity ramp-up, as for many systems
- Goal of the talk is to give in view of the 2021 SPS intensity ramp up operational procedures and limitations for the ZS.
- Bruno gives system overview: new layout for Zs after LS2 - pumps connected directly to tanks; individual gauges for each Zs, interconnects changes as well; BLMs have moved slightly by half a meter.
- Impedance reduction was done as well at interconnects (elliptic bellows and chamber). BI equipped segments are kept round. Electric continuity is enforced. BI equipment is fully refurbished. Zs tanks are new with refurbished motorization, anodes are still the old ones.
- New ion box trap; Zs anodes firmly grounded inside tank (to reduce beam induced sparking); improved diagnostics (for sparking rate, fast voltage measurement, temperature evolution).
- Vacuum interlock set to 1e-7 mbar; might need to be adapted as we may be more sensitive now; this is at the HW interlock - the beam is stopped still via the SIS; this needs to be tested well during HWC, but is usually done. Spark rate interlock 9 sparks / 6 sec; different spark rate windows with different thresholds - is SIS interlocked and need Zs expert to restart. Interface for temperatures is done via wincc, logging needs to be checked (ACTION).
- (ACTION): need to think about BLM threshold management; alignment optimizer needs to be deployed properly (ACTION).
- Zs as well as Ions trap needs to be on while LHC beam is in; PPM modulation is possible; we need to conceptually prepare this possibility such that if it is needed, we are ready to use it. (ACTION); Hannes remarked that ultimately the Zs should be running also with high intensity beams in the supercycle - the strategy here is to have the Zs conditioned with the 30 kV such that eventually it can operate also with HI LHC beam sin the supercycle.
- BI experts required during slow extraction setting up - Verena said the references should already be in the mini-scans - this needs to be checked (ACTION); in general critical commissioning steps should not be scheduled at inconvenient times (ACTION). Francesco asked about sparking rate logging - it would be good to have have this PPM - could be handled via the SPSQC; Bruno will look into this (ACTION). Logging will be looked after by Bruno.
- List of contact persons and experts has been presented.
- SPS 2021 intensity ramp up and its implications for the kickers (M. Barnes)
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- check if 3rd MKDV is in the 2021 impedance model (Elena)
- clarify if the heating rate depends on the starting temperature for a given applied power
- conditioning time will be needed to push the pressure down, need to develop the way to request a sequence of 1,2,3,4 batch injections if possible, or formalise the procedure....(Verena, Hannes)
- still doing the voltage sharing to reduce voltage on MKP-L
- propose new SIS interlock for MKDV vacuum, to prevent tripping the HW interlock
- 1.2ns --> 1.6ns!!! To be updated (ACTION: Mike to update).
- Kicker modifications; operational scenarios table prepared by Carlo was shown;
- Concerns emerged as we are considering high intensity beam which are now being accelerated - this are the scenarios where kicker heating becomes critical.
- No direct correlation between measured temperature and Ferrite temperature also depends on rate of heating. Temperature thresholds need to be conservative.
- Tools / application ready?
- MKP-L is critical and particularly bad for e-cloud and outgassing. Conditioning could be optimized with shorter scrubbing beams (i.e., running with 3 instead of 4 batches for roughly one hour! To be kept in mind for future scrubbing periods - include into procedure.)
- Long-term solution for mitigating problems with MKP-L with kicker re-design; installation earliest possible in YETS 21-22
- Interlock levels given; temperature for MKPs are presently at 60C - could be increased to 70C
- After every cool-down we need to add another mini-intensity ramp up as normally there is a big pressure burst after a 20 - 30 minute break (ACTION: include this in operational procedure and think about automation of sequence).
- Hannes mentioned we should have a similar SW interlock implementation into the SIS as we need to expect long recovery times after a HW interlock has been triggered on the MKD (ACTION: ABT to look into this together with OP).
- Guideline given. Voltage sharing is still done and was confirmed by present experts.
- List of contact persons and experts given.
- Round table:
- No urgent matters discussed
- AOB:
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- Access system, IST, fire safety W34-35, overview has been announced, by-pass for the ABT team is negotiated (still to verify with HSE) and OK.
- Layouts, optics upload test Friday, still one thing to check with Sonia about the 4 ecloud dipoles in LSS1 (Hannes) as floor marking starts next week. Still SSS to check before the final optics can be uploaded.
- Next meeting - TBC:
- Bruno and Mike for procedures
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