Participants: Simon Albright, Maria Amodeo, Fanouria Antoniou, Anthony Beaumont, Marco Buzio, Dario Carloni, Louis De Mallac, Gian Piero Di Giovanni, Christian Grech, Jose Antonio Ferreira Somoza, Alan James Findlay, Vincenzo Forte, Eve Fortescue-Beck, Robert Froeschl, Matthias Haase, Antony Newborough, Carlo Petrone, Serge Pittet, Andrea Santamaria Garcia, Joseph Vella Wallbank.

Approval of minutes

The minutes of the LIU-PSB WG #205 were approved.

Communications

• LIU Beam Performance meeting of the 23^rd of November 2017.

Follow-up of open actions

V. Forte, C. Bracco (2017-12-01): Study collimation and losses in the injection line.

• A mask at the entrance of the BI.DIS was proposed and an internal discussion is still ongoing. Deadline extended to 2017-02-06.

M. Buzio (2017-11-21): Provide document describing the specifications of the B-Train system.

• Deadline extended to 2017-01-16.

M. Buzio (2017-12-01): Investigate and report the options for implementing an online field measurement in the switching dipole BT.BHZ10.

• Deadline extended to 2017-01-16.

B. Riffaud (2017-12-05): Provide a proposal for the support of the equipment in the BTP line.

• Deadline extended to 2017-01-16.

K. Hanke (2017-11-21): find space to store the materials for the Finement cavities installation.

• In spite of the fact that we still not have a solution for the RF relocation issue, it was confirmed that CV shall proceed the 3D integration of the building 141.
• Deadline extended to 2017-01-16.
• After the meeting, it was confirmed that replacement space for the RF equipment has been identified. Room 152-R-001 will be used for assembly and the mezzanine on top of the access point will be used to store the assembled racks.

G. Petrika (2017-10-31): iterate with integration on the installation of the new piping system for cooling.

• A new proposal was presented at the integration meeting. The piping will make the access to the cable trays more difficult, but it is not a showstopper.
• Action closed.

G. Petrika (2017-10-31): Specify the steps to be taken during the removal of the heaters during the YETS.

• A VIC will be held the 20^th of December 2017 to confirm the availability of the scaffolding after an on-site visit on that day.
• Deadline extended to 2017-01-16.

F. Boattini (2017-10-31): follow-up on the tip over issue concerning the installation of the power converters in building 245

• A new version of the demonstrative part was sent to D. Carloni.
• Deadline extended to 2017-01-16.

Update on the B-train measurements (Marco Buzio)

Status of the B-train consolidation project

• MDs in the PS took place during the summer where all cycle types were tested with the new system, showing a 2 uT repeatability.
• The ELENA system is completely new and has been used for 1 year showing satisfying metrological performance. A different method to make an absolute calibration of the B-train system is currently being tested.
• Concerning LEIR, new coils have been installed in the fringe field of the magnet. A couple of MDs were carried out with encouraging results, where they managed to capture and accelerate the beam.

New B-train system for the PSB

• The new acquisition chain was used to make tests offline:
  • FIRESTORM system taking input from ring 3: the relative difference between the FIRESTORM and legacy systems was found to be 2.5e-5.
  • FIRESTORM system taking input from ring 2: differences were observed in terms of saturation and hysteresis.
  • FIRESTORM system taking input from ring 4: the relative difference between the FIRESTORM and legacy systems was found to be 1e-3. This could be accounted by the error in the combination of trim and BdL currents for that reference magnet.
• MDs were carried out:
  • The beam was accelerated by supplying the old coil to the new system the 1^st of November 2017, with less than 0.5 G of difference in all rings.
  • An LHC25 beam was accelerated with the FIRESTORM system the 9^th of November 2017 taking input from new magnetic sensors. A difference of 4 G was observed at high field. A similar behavior was observed the 21^st of November 2017.

Actions

• YETS 17/18: addition of new FMR markers in rings 2 and 4, replacement of WR fiber to RF, installation, and cabling of OASIS chassis.
• The next year will be dedicated to MDs to find optimal configuration and a reliability run to gather statistics.
• LS2: power the new reference magnet with old MPS.

Miscellaneous

• The placement of the new OASIS crate needs to be discussed. There are still ~ 12 kCHF left on budget 99284.
• Concerning the new OASIS sampler, the operational sensors will need additional buffer due to low input impedance.
• Concerning the new fixed displays, many signals could be displayed such as the simulated, predicted, measured and old magnetic fields. Input from operation will be needed to design the vistar.

B-train facility

• The EMI from the overhead conductors needs to be measured as soon as possible.
• The LLRF system could profit from feedback from individual rings, which implies a more complex switching matrix. The extra complexity added needs to be evaluated against the benefits.
• Concerning the new integral dipole coils, a classic straight coil is favored.

Comments

• K. Hanke commented that the deployment could be done in the same way as for the PS B-train system.
• S. Albright asked what are the arguments against using the 4 rings measurements simultaneously. M. Buzio answered that there is an asymmetry among the systems of each ring that makes the wiring more complicated. A. Newborough pointed out that there is a slight asymmetry in the fields of rings 1 and 4 due to the fact there is more steel on the top of the magnet (lifting interface) which slightly reduces the level of saturation compared to the bottom.
• A. Newborough suggested having the two reference magnets simultaneously to compare measurements.

AOB

Proposal of vacuum chambers for BHZ151 and associated magnets (Jose Antonio Ferreira Somoza)

• The aperture of the BHZ151 magnet changed and the supporting system of the chamber was missing, so a new chamber that fits the magnet has been proposed.
• The proposal includes to split the BSW and BHZ chambers and to simplify the supports. The covers were modified to make place for the clamp. Additionally, the bellows were moved to the extraction chambers and the pick-up transitions modified due to an increase in length of the new magnets.
• The budget for the two proposed options is either 330 kCHF or 460 kCHF, depending on the number of spare chambers.

Comments

• K. Hanke commented that the failure rate on this magnet has been zero so far and that the proposal will be studied.

Next LIU-PSB meeting: 16^th of January 2018 on thermomechanical simulations of the PSB scraper by Iñigo Lamas Garcia a proposal for magnet support in the BTM line by Benoit Riffaud.