- 1st meeting (11-04-12):

- Action 1 (EliasM): Discuss with Stephane Fartoukh and Lucio Rossi to set up a collaboration (official papers + some funding) for those who didn't sign a FP7 agreement (with Brussels), i.e. OBF for GSI / TU Darmstadt and MM for La Sapienza => Already done by EM and more news from Lucio Rossi in few weeks.

- Action 2 (All the IBS contributors): Contact JJ to start the benchmarking between the different approaches (codes etc.) which will be used (see also the Task 2.4 web page where some info can be found about the beam parameters and optics to be used + discuss with Stephane Fartoukh). JJ and Michaella Schaumann will make a presentation at the 2nd EVO Task 2.4 meeting (currently foreseen on 30/05/2012).

- Action 3 (MikailZ): Contact NM (for transverse instabilities studies) and ES (for longitudinal instabilities studies) to plan their participation to future LHC MDs.

- 6th meeting (22-01-14):

- Action 4 (NicolasM): Confirm that for both the LHC and HL-LHC beam stability could be reached with almost no Landau damping (as ~ observed during some MDs => Continue also the LHC data analyses).

- Action 5 (NicolasM): What about the TMCI intensity threshold in the presence of the transverse damper and for positive chromaticities? Can this be a problem or should we forget about it?

- Action 6 (NicolasM): Try and understand why the nonlinear RF bucket and the quadrupolar terms of the impedance decrease the TMCI intensity threshold from ~ 4E11 p/b to ~ 3E11 p/b (without transverse damper and for zero chromaticity).

- Action 7 (NicolasM): What about the TMCI at injection? Space charge could also play an important role.

- Action 8 (NicolasM): What about the non-perfect behavior of the transverse damper (in HEADTAIL), including for instance a limit in the detection of the centroid motion (at ~ the microm level)? Some preliminary analyses by XavierB (done with COMBI) seem to indicate that it could lead to some instabilities.

- Action 9 (NicolasM): It has been said in the past that a factor ~ 2 is missing in our impedance model to explain the measured coherent tune shifts. Including the geometric component of the collimators, what is the remaining disagreement factor?

- Action 10 (KevinL): Check that the 2nd RF system in HEADTAIL is working as it should to be able then to perform detailed beam instabilities studies in the presence of 2 RF systems (400 and 800 MHz, and then 400 and 200 MHz).

- Action 11 (ElenaS): What about longitudinal collective effects with 1 and 2 RF systems (400 and 800 MHz, 400 and 200 MHz)?

- Action 12 (GiovanniR): Do we have some news in the e-cloud studies?

- Action 13 (BenoitS): RainerW asked whether some impedance work should be performed for ALICE and/or LHCb, but it was mentioned that some other equipment might be more urgent => What is the prioritized list of impedances which need to be study in more detail?

- Action 14 (NicolasM): Estimate the effect of a Molybdenum coating on the secondary collimators on the beam stability.

- 8th meeting (26-03-14):

- Action 15 (GiovanniR): Follow-up of electron cloud effects => Proposed deadline: Joint HiLumi LHC-LARP Annual Meeting in KEK in November 2014

- The question was raised whether electron cloud build-up could occur in the crab cavities and for which value of the SEY.

- A margin of 150 W has been provided for heat load due electron cloud in the triplets in IR1 and IR5.

- Simulations for the heat load due to electron cloud should be performed in the triplets in IR2 and 8 (so far an extrapolation form measurements has been done) and for all the new elements of the IR1/5 matching section. Sensitivity to orbit (e.g. when the beams are separated should be studied).

- The electron cloud instability threshold resulting by electron cloud in the triplet/matching sections in IR1 and 5 should be estimated.

- Action 16 (NicolasM and BenoitS): Follow-up of impedance effects => Proposed deadline: End of April

- The impedance of the beam screen should be reviewed in light of its operation at 50 K. The effect of magneto-resistance should be included. Some simulations should be performed at 20K, 30K, 40K, 50 K, 60K and 70K since the sensitivity of copper resistivity is very sensitive in this region. The baseline temperature of operation of the beam screen needs to be defined (Action: V. Baglin, who said already that it should be between 30K and 70K).

- Beam position monitors at the triplet are still providing an important contribution to the impedance. The design of the BPMs should be reviewed in collaboration with BI. One could ask the sensitivity of the accuracy and impedance as a function of aperture.