Does LHC need Landau damping Octupoles?

Octupoles have been used in many accelerators or storage rings to Landau damp collective instabilities, from 1962 until now. In view of the present knowledge on LHC coupling impedance and instability theory, we recommend that the LHC be equipped with Landau damping octupoles at each available place close to QF and QD quadrupoles, so as to produce a tune shift of about 1 10-4 at 1 R.M.S. beam size.