Enameled flanges B Goddard LIUSPS 10152021 Brennan Goddard

Enameled flanges B. Goddard, LIU-SPS 10/15/2021 Brennan Goddard 1

QF SSS impedance reduction • 108 QF SSS (a few of which are non-standard in LSS) • Around 60 of QF-BPH flange already fitted with PPS Common solution Multiple configurations 10 convs. 4 convs. 10 convs. Enamelled flanges DIPOLE (MBA) SSS 10/15/2021 Replacement of existing shielding in ~60 locations Diam. 219 QUADRUPOLE (QF) Brennan Goddard 2

Results from tests in SPS • • Not obliged to maintain insulating flanges on at least one side of BPMH body Potential implications + + + Easier and simpler mechanical design? (But new design needed…. ) Improved impedance reduction quality? Additional (missing? ) impedance 10/15/2021 Brennan Goddard 3

half cell Insulated flange MBB MBA MBA MBB CBN connection 10/15/2021 Brennan Goddard 4

60/108 insulated flanges already shorted in 2000 with PPS…will ALL be shorted in LS 2 10/15/2021 Brennan Goddard 5

Mechanical design of final shielding Closes gap Adaptable to 10 convol. bellows RF contact Known solution (pumping ports) 10/15/2021 Brennan Goddard 6

Mechanical design - insulation Al seal Enamelled surfaces No short-circuit! SHIELDING + GAP FILLING 10/15/2021 Brennan Goddard 7

Conclusion • • • Tests showed it is possible to short enamelled flanges at QF No changes to installed BPMH, have keep the enameled flange No design to provide earthing (as opposed to RF shielding) inside vacuum chamber… • • Need to keep insulated flange at upstream end BMPH Need to maintain existing earthing scheme, OR to earth outside like the soft-clamps Propose that we go for the easiest solution: maintain existing earthing and insulated flange VSC can provide gap filler, as requested by IWG 10/15/2021 Brennan Goddard 8

half cell Insulated flange MBB MBA MBA MBB CBN connection 10/15/2021 Brennan Goddard 9