Part of discussion led by Part of discussion led by

Oliver Bruning, CERNOliver Bruning, CERN

Vladimir Shiltsev, LARP/FermilabVladimir Shiltsev, LARP/Fermilab

Soft Ranking of Soft Ranking of LHC Upgrade PossibilitiesLHC Upgrade Possibilities

LHC Upgrades – O.Bruning, V.Shiltsev 2

Factors to be considered Factors to be considered Whether technology available Whether technology available

if not – when Cost of the Upgrade Cost of the Upgrade

<few MEU,<few 10s M,<few 100sM Time to construct & installTime to construct & install Luminosity gain Luminosity gain Physics risk to not get the gain Physics risk to not get the gain

e.g. energy deposition, BB, optics

LHC Upgrades – O.Bruning, V.Shiltsev 3

LHC Upgrades – O.Bruning, V.Shiltsev 4

Thus:Thus: Group A (definetely Group A (definetely

explore)explore) all collimator projects both quad first paths b-b compensation schemes: W, EL

Group B (carefully look into)Short bunch and 12.5-75 nsDipole firstCrab crossing

LHC Upgrades – O.Bruning, V.Shiltsev 5

““Worth the buck?”:Worth the buck?”: Tev(RHIC?) rule of thumb:Tev(RHIC?) rule of thumb: 1M$ upgrade 1M$ upgrade 2-4% in Lumi 2-4% in Lumi Group A Group A

feedback b-b compensation schemes: W, EL new collimation schemes both quad first paths new 12.5-75ns schemes

Group B (carefully look into)Short bunchAll IR upgrades

LHC Upgrades – O.Bruning, V.Shiltsev 6

Manager’s ViewManager’s ViewDepends on “Manager’s Depends on “Manager’s Model” Model”

assume intelligent assume intelligent manager:manager:

Paranoic – minimize the risk Paranoic – minimize the risk Assure SOME improvementAssure SOME improvement Start long lead projects Start long lead projects

ASAPASAP

LHC Upgrades – O.Bruning, V.Shiltsev 7

LHC Upgrades – O.Bruning, V.Shiltsev 8

Thus:Thus: Group A (DO NOW)Group A (DO NOW)

both quad first paths Magnet R&D… Magnet R&D…Magnet R&D

Group B (support now , be prepared to do later) feedback collimator schemes (RC, LEL, Crystals) beam-beam compensation schemes

Group C (make sure assumptions/ estimates right, before rule out): dipole first short bunches crab crossing

LHC Upgrades – O.Bruning, V.Shiltsev 9

Possible Action Items (I)Possible Action Items (I) MAGNETS – all has been said

already

MARS and Fluka has to agree (resolve ~2 difference)

LHC Upgrades – O.Bruning, V.Shiltsev 10

Possible Action Items (II)Possible Action Items (II) On a way to decision in ~1 yr:

Riccardo to wrap up dipole first analysis•Work with Tanaji (visit FNAL for ~mos)

and Ramesh (a week at BNL)Rama to finish crab cavity analysis

•Given Ohmi’s error – reconsider tolerances

•Learn from KEK experience•Generate the most attractive proposal

Short bunches so attractive •Make one more inventive/critical look

LHC Upgrades – O.Bruning, V.Shiltsev 11

Possible Action Items (III)Possible Action Items (III) Deeper collaborative look into items

promising a lot of return for small investment: collaboration important as CERN

people to be busy with commissioning while “helpers” don’t “feel” the machine well

beam demonstrations most convincing allow to attract and keep younger

scientists interested Therefore:

Expand beam-beam simulations collaboration on LEL (Ulrich, VS, FZ)

LHC Upgrades – O.Bruning, V.Shiltsev 12

Cont’dCont’d

simulate LEL hollow collimator (Rogelio, , FZ, VS)

look into low-noise FB tolerances (??) crystal collimation design

considerations (Walter+LARPies) full support of BBLR MDs at RHIC and

rotating collimators (LARPies) very low beta* solutions very

sesnsitive to vibrations, need to look into tolerances and research vibration levels, including beam screen jitter(Riccardo, Vladimir)