Thursday Summary of Working Group I Initial questions I: LHC LUMI 2005; ; ArcidossoOliver Brüning 1

Thursday Summary of Working Group I Initial questions II: LHC LUMI 2005; ; ArcidossoOliver Brüning 2

Thursday Summary of Working Group I main points from morning session for working group I: LHC LUMI 2005; ; ArcidossoOliver Brüning 3 -create a repository for different layout configurations and optics solutions  common data base for future studies  common reference for future discussions  will be discussed on Friday -interesting modular proposal for maximizing F by additional dipole inside experiment  all insertion scenarios benefit  should be pursued independently of final IR design -NiTi is not a viable solution for IR upgrade  is this true for all IR layout and optics proposals (e.g. low gradient triplet solution)?  will be discussed on Friday

Thursday Summary of Working Group I main points from Peter McIntyre’s presentation I: LHC LUMI 2005; ; ArcidossoOliver Brüning 4 -two options for dealing with the increased heat load inside the triplet magnets: 1) construct more robust triplet magnets that can tolerate the increased peak heat load 2) reduce the peak heat load with an upgrade of the TAS absorber:

Thursday Summary of Working Group I main points from Peter McIntyre’s presentation II: LHC LUMI 2005; ; ArcidossoOliver Brüning 5 1) construct more robust triplet magnets that can tolerate the increased peak heat load  structured cable design with Ni 3 Sn and Inconel 718 jacket  Iron less quadrupoles for Q1 with 340 T/m; 40mm aperture; and expected heat tolerances of > 50 W/m  Strong mechanical support and low inductance for “large” quench induced voltages  Confidence that Ni 3 Sn is matured technology by 2010?  Disuccion: Inconel jacket could also be used with NiTi?

Design Q 1 using structured cable 6-on-1 cabling of Nb 3 Sn strand around thin-wall inconel X750 spring tube Draw within a thicker inconel 718 jacket Interior is not impregnated – only region between cables in winding Volumetric cooling to handle volumetric heating from particle losses

Thursday Summary of Working Group I main points from Peter McIntyre’s presentation III: LHC LUMI 2005; ; ArcidossoOliver Brüning 7 2) reduce the peak heat load with an upgrade of the TAS absorber:  levitated dipole coil design with opening at room temperature  B = 8.7 T at 4.5 K; Ni 3 Sn only at inner coil NiTi otherwise  interesting magnet design for a magnetic TAS option

D 1 : levitated-pole dipole Cold iron pole piece, warm iron flux return. Cancel Lorentz forces on coils, pole steel. 8.7 T 4.5 K

Thursday Summary of Working Group I main points from Rama Calaga’s presentation: LHC LUMI 2005; ; ArcidossoOliver Brüning 9 -compensate Lorentz force on the coils by using two race track coils  15 T field for Ni 3 Sn and 8T for NiTi -open mid plane and possibility of installing dedicated absorber material  Interesting option for magnetic TAS design  Who is following this research up? US-LARP has decided to suspend dipole R&D and to concentrate on quadrupoles!

OMD Design Challenges Counteracting large vertical forces between the coils without any structure appears to be a challenge. Good field quality maybe a challenging task due to large midplane gap. Large B peak /B center ratio in magnets with large midplane gap may reduce operating field. The optimum design may look totally different.

In earlier “OMD designs”, absorbers were placed between the the coils. Secondary showers from the absorber deposited a large amount of radiation and heat load on the coils. This problem is fixed in the new design. A True Open Midplane Design

Thursday Summary of Working Group I main points from Frank Zimmermann’s presentation I: LHC LUMI 2005; ; ArcidossoOliver Brüning 12 -geometric reduction factor can be reduced with the help of CRAB cavities (transverse kick  alternative to JPK dipole) -LHC parameters requires between 4MV (small crossing angle) and 100 MV voltage for f = 400MHz  800 MHz -small emittance blowup requires turn-by-turn phase control of better than 0.01 degrees -CRAB cavities require sufficient large beam separation (  installation after D2 plus dog leg separation?)

Super-KEKB crab cavity scheme 2 crab cavities / beam / IP

voltage required for Super-LHC