CERN
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EDMS NO.
FCC-ACC-MIN-0030
FCC
1537241
Date : 2015-08-26
MEETING MINUTES – IN WORK V2
Subject: Infrastructure & Operation
Coordination Group #17
Date and Time: 2015-08-26, from 10:00 to 11:10
Place: 30-6-019
Participants: Michael Benedikt (part.), Davide Bozzini, Paul Collier (chair),
Charlie Cook, André Henriques, Mark Jones, Volker Mertens (chair),
John Osborne, Guillermo Peon, Ingo Rühl, Peter Sollander (secretary),
Laurent Tavian
Excused: Philippe Lebrun, Philippe Gayet, Johannes Gutleber,
Eugenia Hatziangeli
WBS:
File Location/Link: https://edms.cern.ch/document/1537241
Agenda
1.
Minutes of the previous meeting and outstanding actions
2
2.
Status of ongoing work in I&O (tour de table)
5
3.
Any Other Business
6
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1. Minutes of the previous meeting and outstanding actions
Michael reminded the meeting that Philippe Lebrun is leaving on preretirement and that Volker Mertens replaces him as chair of the IOWG. He
thanked Philippe for his efforts on this WG.
Volker thanked Michael and greeted the WG members, welcoming them to
the 17th meeting.
The minutes of the previous meeting were approved with minor corrections
and will be published under EDMS 1531990.
Concerning the length of the machine Paul noted that a choice needs still to
be made among the spectrum of “magic numbers” stemming from the injector
chain. BE-ABP and BE-RF should produce a pre-selection with finer-grained
length intervals around 100 km. Michael said that we should maximize the arc
lengths to maximize the energy. He will ask the two groups to prepare a table
for the IOWG.
Volker reported that K. Oide came up with a FCC-ee geometry fitting better
the FCC-hh footprint, with the FCC-hh interaction point laterally 10 m distant
from the e+e- crossing. The coordinates will be sent to the CE team. Michael
showed a slide and explained that the new solution was ok from synchrotron
radiation and optics aspects. The green trace (FCC-hh) could also be the
trajectory for the top-up lepton injector (bypassing the experiments). He
invited the CE team to study where and how the two tunnels would best
branch off from the common arc. A local study should suffice, without the need
to integrate this change into TOT.
Paul said we should start refining the layout and lengths of the long straight
sections, now that the circumference of 100 km and the arc geometry had
basically been decided. The separate sections of lepton tunnels might be used
as service galleries for the hadron machine, which would bring up questions of
access and safety. Michael agreed that we should make generic descriptions
of what the various points shall house, underground (in both machine tunnels
resp. galleries, and caverns) and on the surface, and how the material shall be
installed and serviced. We should set the goals we want to reach for the next
FCC week (11-15 April 2016); the above descriptions should be on that list.
Paul added that we do not yet know which infrastructure should be installed
above ground and which in the tunnel. He suggested to make a survey among
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the technical groups. A different solution than for LHC might be chosen, but
technical constraints might dictate part of the repartition, e.g. for cryogenics.
Volker noted that criteria of accessibility and availability are likely to play a
major role as well.
The open action points were reviewed, complementing the above discussions.
Volker suggested to add dates to the items where possible.
Actions are ordered by completion status, new and ongoing actions first.
Status is one of {New, Ongoing, On hold, Completed, Postponed or Cancelled}.
Description and Comments
Develop a map indicating electrical power and water cooling
needs at different locations around FCC ring.
Status
Ongoing
Assigned
I&O wg
Identify limits on sector lengths coming from technical
Ongoing
infrastructure and accelerator systems
Mauro: no hard limits, in the worst case add ventilation booster.
I&O wg,
Accelerator
systems
Progress with study leading to selection on single or double
tunnel option for work towards CDR.
Ongoing
I&O wg
Estimate radiation doses, “cooling” times and remote-handling
needs for removal of LHC insertions towards its use as FCC
high-energy injector (see Markus’ presentation on 29th July).
Ongoing
HSE
Define straight sections to detail level, which permits
documenting infrastructure requirements and constraints.
Ongoing
Accelerator
design
Study ground settling in newly excavated tunnel and impact on
machine alignment. Checking tunnel stability. Tunnel and
caverns are concerned.
Ongoing
M. Jones,
Accelerator
physics
Create a top-down operation model of the injector chain and
use for FCC availability studies. Work is ongoing and could be
presented in October 2015 (see Status of ongoing work)
Ongoing
RAMS team
Define work topics, work period and supervision line for all
personnel requests.
Ongoing
Supervisors
Review practical limits on magnet mass and length.
Not started
I&O wg
Review and validate WBS items.
Ongoing
I&O wg
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Description and Comments
Status
Assigned
Elaborate and communicate work package descriptions
(identified by 4 digits in column A of the WBS) of the
Infrastructure & Operation study: 5 lines or about 100 words
with a general description and a focus on the work foreseen.
Ongoing
I&O wg
Detail cooling and ventilation power consumption estimates.
Ongoing
M. Nonis
G. Peon
Hooking on the point of single vs. double tunnel Paul inquired whether cost
would be the only criterion for decision. Michael replied that ventilation
concepts including duct cross sections need to be worked out which should
show up advantages and drawbacks. Guillermo commented that the pressure
drop along the tunnel and consequently the pressure difference building up is
not expected to be a showstopper for a two-tunnel concept. Andre said that 7
m of soil between the two tunnels would be enough for radioprotection
purposes. It is important to define whether the second tunnel would only serve
as escape route or also contain equipment and be used for transport. To
proceed with the RP studies Markus seemed to require further data; Andre
will check which.
Concerning magnet mass and length limits Ingo said that as long as the
magnets would not become much longer or heavier than those of LHC or HLLHC this could be handled in a straightforward way. Volker will bring this point
to the Special Technologies WG, asking for first indications.
Peter explained that the reliability study (RAMS) is progressing. A first model
of the LHC accelerator chain with its failure modes and an accelerator schedule
has been assembled and can simulate the LHC beam production. The model
can later be transposed to the FCC to simulate integrated luminosity
production based on equipment failure rates, beam cycles and accelerator
schedules. The reliability team will meet in Finland end of September. A
presentation to the IOWG can be scheduled for October.
Volker said that we should define the goals of the various work packages
more precisely, with priorities and dates. The priorities shall also define the
resources to assign to each work package (number of staff, fellows, project
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associates). He will prepare a framework for this and start discussing details to
fill in with the people involved in each work package.
He also noted that he is supposed to give a presentation to the Special
Technologies Working Group in September. He will come to see FCC IOWG
team members individually, to collect information as needed.
2. Status of ongoing work in I&O (tour de table)
John is organising a meeting with engineers and geologists from ARUP,
AMBERG and GADZ on September 2nd to understand what is needed to study
the two 100 km options in more detail.
Andre is finalising the paperwork for a collaboration with ESS on fire dynamics
and optimisation of smoke extraction.
Laurent reported that the design of a cryogenic system for the FCC-hh
machine is progressing. The basic idea is to have 10 cryogenic plants
distributed around the 100 km. An option would be 20 smaller plants to reduce
the complexity, size and cost of each plant but with the likely disadvantage of
lower overall availability. The magnet temperature will have a big impact on
the design of the cryogenics system. In addition to the 1.9 and 4.5 K options
magnet people suggested that there might be an optimum temperature
between the two (4.0 K ?) which shall also be studied. This would allow to
work at around 800 mbar thus requiring fewer pumping stages.
Laurent also reported that a visit to MAN Diesel & Turbo in Zurich was very
interesting and provided insight into the next generation of warm compressors
which are smaller in size. John inquired about noise levels of the new
machines. Laurent replied that noise-reduction measures will be required. The
goal is to minimise the equipment to be installed underground.
Paul inquired about assumptions on cool-down and warm-up times for the
FCC. Laurent replied that they are currently assuming the same times as in
the LHC. In order to achieve those times the liquid nitrogen pre-coolers would
have to be much bigger than the ones used today. To get the corresponding
number of nitrogen trucks to the sites will be a logistics challenge.
Davide has started the design of the overall electrical distribution system. He
is interested to know where the big consumers will be located geographically.
Laurent explained that the basic cryogenics layout is the one he presented at
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the FCC Week in Washington. In calculating the power consumption he is
taking a conservative estimate for the efficiency which can be expected in the
future (40 %, compared to 30 % at present, being ultimately limited by the
efficiency of the Carnot cycle).
Laurent proposed to present the current cryogenics study at the next
meeting. He also announced that he will leave the cryogenics group as of
November 1st this year but remain member of this Working Group.
During the very hot summer weeks Davide has also looked in more detail at
power consumption for EN-CV. He and Guillermo will present the findings at
the next IOWG.
Mark foresees to make a presentation in October related to ground settling
and stability. Paul asked to include the impact of fault lines. John suggested
to look back what has happened elsewhere.
Mark mentioned that Survey have been analysing the current CERN reference
systems by comparison with geodetic data imported directly from the Swiss
gravity field model and astro-geodetic measurements. Initial conclusions are
that the misalignment between the axes of the CERN Geodetic Reference
Frame and the International Terrestrial Reference Frame should be taken into
account when transforming to the CERN Coordinate System. The best way to
do this is now being investigated.
Survey has also carried out some preliminary assessments of the smoothing
alignment of the FCC. The initial assumption was that the necessary precision
would be the same as for the LHC. Under these conditions simulation show
that approximately the same measurement precision will be needed but over a
distance twice as long. Also after some discussions with Daniel Schulte, from
the hadron collider study group, it seems that one may need to increase the
precision by a factor 2. Both assessments imply that the instruments and
technologies currently used may need to be revised.
3. Any Other Business
Due to the Chamonix workshop in January 2016 it was decided to advance the
IOWG meeting of January 27th to January 20th.
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The next meeting will take place on Wednesday, September 23rd at 10:00 in
30/6-019, and tentatively feature presentations from Laurent, Davide and
Guillermo as mentioned above.
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