Thursday Summary of Working Group I

Thursday Summary of Working Group IInitial questions I:

LHC LUMI 2005; 2.9.2005; Arcidosso Oliver Brüning 1

3) Hardware design issues:

Question / Topic goal of presentation Potential speaker

magnet lifetime issues how scales the magnet lifetime with radiation and L

general magnet performance issues what is the peak coil field in a dipole for various SC materials Ranko Ostojic or

what is the peak coil field in a quadrupole for various SC materials Louis Walckiers

how does the peak coil field scale with the heat load and L

cos-theta magnet design options how much power can be cooled at 4.5 K Ranko Ostojic or

how much power can be cooled at 1.9K Louis Walckiers

peak field estimates for this design type

field quality estimates for this design type

present questions still to be addressed in future studies

2-in-1 magnet design issues what is the minimum required aperture spacing for a 2-in-1 quadrupole

design Ranko Ostojic orcan a 2-in-1 quadrupole design feature a central hole for the neutron flux

Louis Walckiers

Thursday Summary of Working Group IInitial questions II:

LHC LUMI 2005; 2.9.2005; Arcidosso Oliver Brüning 2

3) Hardware design issues:

Question / Topic goal of presentation Potential speaker

race track magnet design options how much power can be cooled at 4.5 K Rama Calaga &

how much power can be cooled at 1.9 K

peak field estimates for this design type Peter McIntyre on structured cable

field quality estimates for this design type magnets with internal cooling

present questions still to be addressed in future studies

levitating magnet design options how much power can be cooled at 4.5 K Peter McIntire

how much power can be cooled at 1.9 K

peak field estimates for this design type

field quality estimates for this design type

present questions still to be addressed in future studies

Issues related to crossing angles what is the required transverse field for crab cavities? Frank Zimmermannhow does the required longitudinal space of a Crab cavity scale with the required peak transverse field?how does the noise excitation in a Crab cavity scale with the required peak field?

what are the options for correcting the dispersion due to a large x-ing

minimum required x-ing angle from long-range beam-beam point of view

Related questions given to the WG by the Work Shop Organizers

need of technological improvement of the triplet magnets

layout and compatibility with the existing experimental devices

Thursday Summary of Working Group Imain points from morning session for working group I:

LHC LUMI 2005; 2.9.2005; Arcidosso Oliver 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 Imain points from Peter McIntyre’s presentation I:

LHC LUMI 2005; 2.9.2005; Arcidosso Oliver 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 Imain points from Peter McIntyre’s presentation II:

LHC LUMI 2005; 2.9.2005; Arcidosso Oliver Brüning 5

1) construct more robust triplet magnets that can tolerate the increased peak heat load

structured cable design with Ni3Sn 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 Ni3Sn is matured technology by 2010?

Disuccion: Inconel jacket could also be used with NiTi?

Design Q1 using structured cable

6-on-1 cabling of Nb3Sn 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 Imain points from Peter McIntyre’s presentation III:

LHC LUMI 2005; 2.9.2005; Arcidosso Oliver Brüning 7

2) reduce the peak heat load with an upgrade of the TAS absorber:

levitated dipole coil design with opening at room temperatureB = 8.7 T at 4.5 K; Ni3Sn only at inner coil NiTi otherwise

interesting magnet design for a magnetic TAS option

D1: 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 Imain points from Rama Calaga’s presentation:

LHC LUMI 2005; 2.9.2005; Arcidosso Oliver Brüning 9

-compensate Lorentz force on the coils by using two race track coils 15 T field for Ni3Sn 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 Bpeak/Bcenter 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 Imain points from Frank Zimmermann’s presentation I:

LHC LUMI 2005; 2.9.2005; Arcidosso Oliver 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?)

RF Deflector( Crab Cavity )

Head-onCollision

Crossing Angle (11 x 2 m rad.)

Electrons PositronsLERHER

1.41 MV

1.41 MV

1.44 MV

1.44 MV

Super-KEKB crab cavity scheme

2 crab cavities / beam / IP

voltage required for Super-LHC