Minutes RF structure meeting 14.11.2008

M. Vretenar, F.Gerigk, S. Ramberger, R. Wegner, F. Grespan, N. Alharbi, M. Schuh

DTL

• Bead-Pull measurements done without post couplers and moving tuners
  • no effect on acc. field
  • each measurement must be normalized separately
• Adapted motor control software to minimize integration error (action GiovanniDeMichele)
• HOM simulations with Superfish done by SuitbertRamberger
• Measurement with detuned post coupler (action FrancescoGrespan)
• Move Bead-Pull measurement system to NaderAlharbi model
• Prepare hot prototype for high power test
• Open to check end cell position and machine if necessary (action SuitbertRamberger GiovanniDeMichele, FrancescoGrespan)
  • machined end cell increase f
  • measure influence on field tilt

PIMS

• structure temperature increases about 60k using a semi-analytic estimate with linac 4 duty cycle (SuitbertRamberger), so additional cooling needed
• further calculation should be done (action FrankGerigk): added after the meeting: In the water distribution system it is foreseen to cool all PIMS structures. So far an average heat load of 2.4 kW per structure is assumed, which corresponds to the LP-SPL duty cycle. For compatibility with the LP-SPL and to avoid excessive heating of the air in the tunnel it is clear that the water circuits have to be installed right from the beginning (FG).

HOM

• Talk about power dissipation due to HOMs at SPL study group meeting by MarcelSchuh
• Limits for Q_ex concerning cryo power due to HOM excitations are 10⁷

AOB

• added after the meeting: Vladimir is preparing a 2nd bead-pull system, re-using the drawings and tools that he used for the last one. This should speed up future measurements (FG)