LIU-PM-MIN-0194
EDMS 1547781
LIU project team meeting
Notes from the meeting held on 21 September 2015
Present: S. Gilardoni, D. Manglunki, M. Meddahi, G. Rumolo
Excused:
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Progress on the main WP activities with spending status (S. Gilardoni)
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The EVM structure has been implemented in APT, only the WP on LLRF for slip
stacking (+200 – 400 kCHF) is still missing. The CtC has not changed – budget to
be defined for LEBT if work on improving brightness from the source is needed.
Benoit is checking the data consistency
All the contributions to the TDR have been received and first skeleton is available.
The introduction is being edited. The part in which Heiko describes alternative
production schemes will be published in a separated note, instead of being a part
of the main body of the TDR.
Linac3 (improvement of source – LEBT): No issues have been found with
production of enlarged vacuum chamber and einzel lens so far. The pepper pot for
emittance measurements had to be removed, because the device caused an
aperture restriction and consequent reduction of the Linac current (not clear
actually, because the current has got back to the value it had before the pepper
pot removal). The pepper pot is still under guarantee and has been sent back to
the manufacturer to possibly enlarge the aperture. It might then be re-installed at
the next YETS. Anyway, a first set of data has been acquired with it and will be
analysed by Giulia together with simulations to try to identify the ion distribution
out of the source, although it won’t be probably sufficient.
LEIR produced 4.6e8 ions at extraction, as in 2013. This is in spite of the lower
current from the Linac3, because the only difference is that now the losses at
capture are lower. This is consistent with what was observed in the past, even
when you inject more beam into LEIR, the final value will not change due to the
losses at capture. The program of LEIR studies is following the original planning.
Most of the work on the RF capture losses can be done now that the performance
for the operational beam has been re-established (instability, transverse damper,
emittance blow up, space charge, etc.). There seems to be a manpower problem
anyway, because machine development for ions is always considered low priority.
It could be helpful to define a day per week in which the LEIR machine studies
take place and the necessary experts should be available. This day could be
Wednesday (Monday: Linac3, Tuesday: PS, Thursday & Friday: SPS). The
problem of the low priority of the ions has been already raised several times with
the higher management, but if nothing has changed so far, maybe it could be
useful to have some concrete examples to present when the question is
addressed. First report at the next general LIU-PT meeting on 8 October
SPS 1) Slip stacking: LLRF Requirements were summarized at a dedicated LIUSPS Coordination meeting. An EDMS document on the LLRF specifications was
released on Friday 19/09 and is presently in status of Engineering check.
Concerning the resources, Philippe said that a full upgrade would also re-design
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the Synchro module and Radial Loop, which is not strictly required for LIU but
desirable considering the obsolescence of the hardware. A crude estimate for
these two systems is an additional 200 kCHF and 2 FTE. This is in addition to the
200 kCHF + 2 FTE already requested. A fellow is planned for mid 2016 to work on
the hardware, Elena might also need somebody to follow up on the simulation
side. Some tests could be already done this year in MDs (beam lifetime without
phase loop, momentum aperture, RF program optimization); 2) Christian Carli and
Fanouria Antoniou (presently paid by HL-LHC, her work on LIU to be formally
arranged in the next year) are presently looking into IBS models to estimate beam
parameters dependencies at SPS flat bottom, but the losses seem more
consistent with Touschek effect than with IBS. SPS MDs are planned to verify
parameter dependencies of beam lifetime (bunch intensity, length, emittance).
One Technical Student working with Fanouria will be requested.
A parameter table including the HL-LHC target together with LIU achievable and
achieved ion parameters at the SPS exit is being produced. The document is
almost finalized, J. Jowett sent recently some numbers that were missing, but the
number of bunches reported in this table needs to be double-checked. By the end
of this week the final LIU table with all agreed scenarios will be released as an
EDMS document (1533832).
AOB
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The next ‘general’ LIU-PT meeting will be held on Thursday 8 October 2015 in
Room 865-1-D17, from 09:00 to 10:00.
Minutes by G. Rumolo
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