1. impedance aspects for the beam screen

2. LHC beam pipe Current model in impedance database ZBASE (N. Mounet):
No sharp HOM expected with this model

3. LHC beam pipe
More accurate model should account for the real beam screen geometry…
No sharp HOM expected with this model either (confirmed also by Carlo)  no HOM are expected to be created by weld or pumping holes

4. … and the PIMS!
Difficult geometry to simulate, to be crosschecked

5. In conclusion, if elements are conforming, we do not expect sharp HOMs around between 1 and 3 GHz.
To be confirmed for the PIMS
Non confirming simulations will be performed