LIU-PM-MIN-0148
EDMS 1451476
LIU project team meeting
Notes from the meeting held on 11 December 2014
Present: J. Coupard, A. Funken, S. Gilardoni, B. Goddard, K. Hanke, M. Meddahi,
G. Rumolo
Excused: A. Lombardi, M. Vretenar
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Matters arising
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TDR: The electronic version of the LIU-TDR is now available here.
We will get an AT sector document number, and a printed version will be available
by mid-January 2015. We thank all the LIU activity leaders and deputies for all the
work done, as well as the invaluable support of Cécile Noels and Valeria
Brancolini. An email has been sent to the sector and all department heads plus
HL-LHC project managers, their comments or questions are expected before 15th
December 2014. After this date, the printing process will begin. A cover has been
also made and the table of contents will be made after all the comments are
received. 250 copies will be delivered (price estimate has been asked for up to
500 copies), all in black and white. We could ask for a quote also from a local
printing company, which was also used for the PS 50 years and turned out to be
cheaper (and for copies in color) than the UK company. Thank you again for your
support and for all the work done by the departments and groups involved in this
process.
EVM reporting: With the help of Benoit Daudin, Malika extracted all information
from the LIU EVM to compile the LIU EVM report. By Wednesday 3 December the
EVM coordinators have created a new baseline, which will have the status ‘In
Preparation’ and will include all the existing WUs. The different activity
coordinators should now check. This implies that all progress reports will be
suspended until the new baseline is released (by end January 2015). Until 15
January, all EVM coordinators will perform/coordinate the updates on the work
units (timeline, spending profile from 2014 to post-LS2) with the new data just
collected. Some important guidelines:
o Do not use an existing WU to declare a completely different new work. If it is
needed, cancel the obsolete wu and create a new one;
o Do not exceed your Cost to Completion;
o If a deliverable has been declared as completed, it should remain ‘complete’ in
the new baseline!
Latest by the end of January 2015, the new LIU baseline (for protons) will be
released.
The LIU Project Roadmap document has been changed into LIU Project
Description and has been approved and uploaded on EDMS. The document was
sent to the Council and the budget has been approved.
Cost & Scheduling Review: there were two meetings, one in preparation with F.
Bordry, B. Delille and L. Rossi and another one also with N. Holtkamp. The final
schedule has been agreed upon and it has been circulated (available on EDMS
and Indico). The number of breakout sessions has been reduced to 5, which
makes the whole review easier to attend and manage. The part on
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simulation/model/experimental cross-checks is now included in each machine talk,
so this subject will be shorter (as is was not the real focus of the C&S review). The
next review preparatory steps should now be discussed.
In response to Erk Jensen, who asked about the possible future LIU uses of the
specialized RP workshop (building 109, recently refurbished), the following
requests have been collected:
LIU-PSB - Klaus:
o ABT group: reserve a generic slot of turning/ milling for a couple of weeks for
magnet upgrade work
o Vacuum group: block B109 for 1-2 weeks during LS2 for PSB vacuum work
o BI group: BI.BTV30 : 2 days for vacuum chamber modification and 2.5 days for
tank modification. BT.BTV30: 2 days for vacuum chamber modification
LIU-PS - Simone:
o ABT group: Small tasks to be done in the RP workshop in blg 109 during LS2.
But the tasks will be limited to small works to adapt old parts to the newly to
install septa
o Magnet group: radioactive workshop will be needed sporadically, but can’t
provide a schedule since it is based on a case by case principle
LIU-SPS - Brennan:
o RF group: modify some supporting systems of both 200 MHz and 800 MHz
cavities – work to be check with RP as the supports come from the SPS
machine but are not activated
The implications of having all Linac4/PSB connection equipment ready by the end
of 2016, while the L4 to PSB connection is only scheduled for LS2, have been
discussed. This decision has consequences on other equipment procurement,
which could otherwise be ready for an earlier installation, e.g. during (E)YETS, in
view of anticipating as much as possible LS2 activities. As the EYETS is currently
too short to perform the L4/PSB connection at the end of 2016, it should be either
decided that the connection will take place in LS2 and all related equipment
should be ready by then (and not by end of 2016) or it should be stated that this
EYETS will be longer and would allow the connection to be made (including both
hardware + 2.5 beam commissioning months needed to have the connection
ready only for LHC beams). In case of Linac2 failure, Linac4 could provide 50 MeV
protons (to replace Linac2) in about one month (for operation with low energy
protons), to which a couple weeks for beams setting-up should be added.
Feedback and recommendations are expected from the management, as it would
be important to converge to a final decision by the end of this year for planning
reasons. Meeting on Monday at 16:30 with Klaus, Maurizio and Freddy to discuss
the scenario to consider (Brennan is away), final date to be confirmed.
Round table on progress on the various activities
PSB – K. Hanke
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Reference magnet will be put in the new building with new power supply. Old
system will stay where it is as a back up. Pricewise, this turned out to be even a
little cheaper than moving the old reference magnet.
No technical topic today’s meeting.
EN/STI, the new WU responsible has taken over and will take care of dump and
intercepting devices (like the beamscope).
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EN/CV: budget situation needs to be clarified, because at the time of the feasibility
study it was agreed with Simon that 4.5 MCHF were allocated in CONS for the
complete refurbishment of the cooling and ventilation stations for the PSB complex
to take place during LS2, but now doubts have been raised. Since it is essential
that this consolidation activity is taking place to ensure reliable operation of the
PSB as well as the successful completion of the LIU-PSB project, and according
to LIU time lines (i.e. during Ls2), it should be confirmed back to LIU as soon as
possible that it is budgeted within CONS. Action: Malika
PS – S. Gilardoni
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Meeting on Tuesday, study on dynamics of injection trajectories when
desynchronizing one bumper. Simulations agree with measurements, so now
predictions to 2 GeV can be trusted. The fellow who worked on this subject is
leaving and a new one is coming from China. However, since she is an expert in
impedances and instabilities, she will work with Guido on transition instabilities,
while the new hired fellow (who was supposed to work on instabilities) will be
moved to the injection studies.
Design of the magnets of the injection bumpers is delayed because responsible
will be away for a few months. However, a first version of the design is already
available to allow EPC to progress with the design of the power converters. The
design of the magnet for the IPM will be delayed, but this should not be a problem,
because it can be integrated in the IPM design at a later stage.
MDs on 80 bunch train progressing. It was possible to kick out 90% of a selected
bunch using the transverse damper, which means we are very close to the final
production of this beam.
BLMs in the PS ring: The budget situation needs to be clarified, there are
564kCHF missing for the electronics of the PS ring BLM system. This additional
amount could be partially funded from underspending on other LIU BI fronts, as
the LIU project could probably fund the BI request for just half the money, implying
that ~250 kCHF would have to be found from other sources.
SPS – B. Goddard
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800 MHz commissioning: Basically on track, the 3 MDs were used to get the LL
working, still a few details to solve but essentially looking good, and on track for
the 2nd cavity to be ready in June.
Impedance reduction of vacuum flanges: Now being actively studies by VSC with
the SPS teams, still need clear FS to be generated. Aiming to be ready to decide
mid 2015, including completion of analysis and simulation.
External dump: LSS5 CE studies ongoing, converging with reasonable looking
tunnel and cavern designs. Extraction is still the limit to the dynamic range presently confident of being able to extract all beam >200 GeV, but looking at
TIDH type object for lower energy beams. Implications for other systems in LSS5
to investigate soon. The subject will be soon presented in a forthcoming LIU-SPS
Coordination meeting for information and to start assessing other project
implications (e.g., beam dynamics, work planning, etc.)
TCDI upgrade: ECR refused from S.Grillot, on installation of platforms in LHC
tunnel - one location in UJ88 conflicts with space needed for one new collimator.
Platforms are already installed - this one will need to be moved in LS2.
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IONS – mail from D. Manglunki + S. Gilardoni
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LEIR MDs on linear model with Ar beam progressing (M.Bodendorfer): studies on
long flat bottom at injection energy; delayed injection timing to assess magnetic
overshoot. A fellow will be hired to help Michael on these studies.
2 days given back by Ar setting in SPS to RF MDs (Thu 4/12 & 11/12)
ECR on PS safety chain, to allow ion injection during PS access presented at last
IEFC.
LEIR Dump: for the 2nd time, the person in charge is leaving due to termination of
LD contract (first Cesare, now Ivo). Antonio taking over, which will hopefully cause
no delay. First draft on external LEIR dump will be circulated.
LEIR will be closed Friday night after last SPS Ar setting up session (exact time
tbc). G. Bellodi is starting as new EVM coordinator (part on Linac3 is in good
shape, part on LEIR still under work)
J. Jowett said that the ALICE upgrade was approved with twice the target
luminosity that is being considered in present studies.
Technical coordination – J. Coupard
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Meeting yesterday to clarify role of the LIU-PLI meeting, as was already discussed
in the LIU-PT meeting last time. Furthermore, there was a very complete
presentation on integration.
In Linac4 beam has been stopped until next year. Measurements were taken with
12-13 mA, current value limited by the source. In January installation works will
progress, but it is still uncertain that couplers will be provided by the firm. The use
of a source providing 50 mA is now in the planning for July 2015.
For planning it is important to get all information about times and cool down times
for all (E)YETSs until LS2.
Safety – A. Funken
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LIU-SPS, external beam dump tunnel: the HSE safety requirements for the civil
engineering part have been issued by C. Colloca, EDMS 1452563. The complete
Launch Safety Agreement will be sent beginning of January 2015.
The new fellow, Lelyzaveta Kobzeva (ielyzaveta.kobzeva@cern.ch), will take part
to the 1st LIU-PT in January 2015 to be presented to the LIU management team.
Scrubbing run – G. Rumolo
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Yesterday afternoon another 2.5 days SPS scrubbing run finished.
Monday was devoted to injecting high intensity LHC beams into the SPS. 4
batches with up to 2e11 p/b were injected into the SPS (bunch length was 4.5 ns
at SPS injection) and the electron cloud effects on these beams was very strong,
manifesting itself with instabilities, blow up and degraded lifetime. Unlike in the
past, the instabilities were mainly in the horizontal plane, as the single bunch
instabilities in the vertical plane can be stabilized by the use of the Q20 optics.
Another reason for that could be also a recrudescence of the electron cloud in
other regions than dipoles at these very high bunch intensities. It is clear that the
electron cloud is still a strong limiting factor when going to higher intensities and
both ‘scrubbability’ and then possibly the amount of scrubbing needed to obtain a
good beam quality will need to be assessed next year.
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Acceleration of the doublet beam proved very complicated and couldn’t delver
more than 1.3e11 p/doublet at flat top. The attempt to use a slow ramp (three
times slower) was not successful due to instabilities during the ramp, which led to
high losses and beam dumps. While on one side it was seen that the doublet
suffers from its enhanced electron cloud and it may improve with increased
scrubbing, it also became clear that the acceleration of one or two batches of
doublets for use in the LHC in 2015 also needs a cleaner cycle set up in the SPS.
The production of doublet beams would need to be moved from MD to set up
mode and should be followed up regularly at least on a weekly basis in the SPS
involving all the relevant experts for the different systems (e.g. RF, LLRF,
transverse damper) and giving them enough time to sort out the different issues.
After a full night without beam due to a problem with a quadrupole in the TT10, the
final day was devoted to testing 8b+4e and the BCMS beam on the nominal LHC
filling cycle. As expected, the 8b+4e does not produce significant electron cloud (a
faint signal could be seen in the electron cloud monitors only at higher energies),
but it surprisingly awakened the ZS (with large outgassing spikes and sparking).
This should actually indicate that indeed the ZS problem is an impedance related
issue rather than an electron cloud problem, and its impedance must interacting
with some additional line in the 8b+4e beam spectrum. The BCMS beam was also
in a very good shape, providing 1.15e11 p/b at flat top within emittances around
1.6-1.9 um. Capture losses were quite high in general, which requires additional
studies.
AOB
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This is the last LIU-PT meeting of 2014. The next LIU-PT meeting will take place
on 8 January, 2014, from 09:00 to 10:00 in Room 865-1D17.
Minutes by G. Rumolo
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