Participants: Simon Albright, Alfred Blas, Jean-Baptiste Bonnamy, Dario Carloni, Julie Coupard, Louis De Mallac, Gian Piero Di Giovanni, Jose Antonio Ferreira Somoza, Alessandro Floriduz, Marine Gourber-Pace, Matthias Haase, Christoph Hessler, Gerd Kotzian, Bettina Mikulec, Antony Newborough, Gabor Petrika, Sylvie Prodon, Andrea Santamaria Garcia, Jocelyn Tan, Wolfgang Hofle.

Approval of minutes

The minutes of the LIU-PSB WG #202 were approved.

Communications

Report on the LIU Project meeting of the 19^th of October 2017:

• A new combined LIU-OP working group has been set up, chaired by V. Kain and G. Rumolo. The working group will tackle the beam commissioning after LS2, but will start to prepare now with the YETS 17-18.
• J. Coupard presented the status of the LS2 planning. The concerned document should be released by March 2018.

Follow-up of open actions

T. Dobers (2017-10-24): change the value of the wide band pick-up in Geode to the one given by the 3D scan.

• Not present. Will contact T. Dobers.

T. Dobers (2017-10-31): make a list of starting points of the transfer lines to be sent for approval in an EDMS document.

• A discussion is ongoing between I. Efthymiopoulos, T. Birtwistle, T. Dobers and C. Hessler. The outcome will be presented during the next LIU-PSB WG meeting.

K. Hanke (2017-10-24): find space to store the materials for the Finemet cavity installation.

• K. Hanke had a meeting with G. Petrika, M. Haase and the BE space manager E. Sanchez-Corral. The meeting was not conclusive and they are waiting for a proposal from E. Sanchez-Corral.

K. Hanke (2017-10-31): attend an integration meeting concerning the layout drawings for the main bending magnets.

• K. Hanke assisted to the meeting, where it was agreed that additional drawings will be produced. Action to be closed.

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

• Two piping proposals were presented and rejected at the integration meeting. G. Petrika said that he would like to modify the second option presented and re-iterate. Another option was proposed by SMB, which is a more complex, but possible solution. Action to be extended to 2017-11-07.

TFB Status (Alfred Blas)

• The transverse feedback takes the signal from a single pick-up located in sector 4L5 and kicks the beam in sector 3L1 to damp transverse instabilities.
• The kicker location was chosen to reduce the betatron phase error (1.75 deg for a fractional tune q=0.2).
• The system’s bandwidth is limited to 13 MHz for more robustness.
• Concerning the upgrades for 2018, the TFB system will be available to cover operation up to 2 GeV. The power per electrode will be extended to 800 W and the bandwidth increased to 20 MHz. The sampling will be digital, at 64 samples per revolution. The 100 MHz analogue system will be kept alive until the nominal intensity is reached with Linac 4.
• Plan for the YETS 17-18:
  • Installation of 16 amplifiers and 8 power supplies (two amplifiers powered by one power supply).
  • Interconnections to PLC.
  • Installation of 16 test boards for signal processing.
  • Installation of VME crate.
  • 32 old cables to be replaced by new ones.
• In LS2 a fixed clock will be used as reference, whereas a sweeping clock system will be tested in 2018. The firmware will then need to be reconfigured.

Comments

• B. Mikulec asked how to distinguish if the measurement is above or below the half integer tune, since at the PSB it is crossed at injection in the vertical plane. W. Hofle answered that the system cannot work at the half integer resonance. Discussions will continue offline.
• M. Gourber-Pace commented that keeping the 100 MHz system alive implies some work from their part since the technology present after LS2 will not be compliant with an analogue system. The analogue system will need to be upgraded, tested and validated in 2018. M. Gourber-Pace asked when the system would be ready for testing, and A. Blas answered that it will be ready by February 2018. B. Mikulec suggested to plan the test for after the first technical stop.
• J. Coupard commented that the TFB activities described were not included in the RF activities presented in the coordination meeting last week, and that they should be added to the program, as well as the cabling activities for the YETS 17-18. For the cabling activities B. Mikulec confirmed that they have already been added and accepted by G. Minchev.
• B. Mikulec asked if the BOSS unit would stay after LS2. A. Blas answered that if there are important orbit changes during the cycle, like for an extraction bump, the digital board can saturate and they might need the BOSS unit. B. Mikulec suggested to do some tests in the machine before the YETS 17-18.
• M. Gourber-Pace asked if there is something to follow up concerning the OASIS signals. A. Blas answered that indeed there might be the need for additional OASIS signals when the two systems run in parallel, and that he will get back to CO with the information.
• W. Hofle proposed to convert the signal from the fixed clock reference instead of changing the firmware.

AOB

LIU-PSB EVM Status (Sylvie Prodon)

• The cost variance is globally correct.
• The project is 1.6 months behind the active baseline and 3.6 behind the cost and schedule review baseline, which will need to be reported at the cost and schedule review meeting that will happen on March 2018. Depending on what exactly will be requested by F. Bordry, it might be necessary to explain in more detail this difference.
• Improvements were observed in RF, SMB and ABT.
• Regarding the CERN Expenditure Tracking for the LIU-PSB project, there is currently 62% of charges and 91% of commitment versus the 64% of charges and 92% commitment objectives for the 1st of November 2017.

Tour de table

• G. P. Di Giovanni reported that the EDMS document 1578463 on the new PSB scraper has been approved.
• C. Hessler commented that he is checking the aperture files for LIU in the PSB-to-PS transfer lines, as he found some inconsistencies.

Next LIU-PSB meeting: 7^th of November on the PSB optics status.