The HiLumi LHC Design Study is included in the High Luminosity LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.

LHC PIC performance and aspects related to the injectors

G. Arduini with input from O. Brüning, R. De Maria, S. Fartoukh, P. Fessia, S. Gilardoni, B. Gorini, L. Rossi, G. Rumolo, R. Tomàs

2

Main Hardware changes: being finalizedPIC

• New TAS, 60 mm, IT, D1, 150 mm, correctors

• New collimators with buttons, new materials for robustness and impedance, new TCTs in IR1-5 for D2-Q5 for cleaning and protection

• Arc sextupoles (MS) at 600A

• SC links in IR15, QRL

• New powering with SC links at P7 (RR)

• New Cryoplant P4 for SCRF

• Cryoplants in P1,5

• Beam pipes and Y chamber between D1 and TAN3

Filling schemes 25 ns

Filling scheme Total IP1-5 IP2 IP8BCMS: 48b 6 Ps inj, 12 SPS inj 2604 2592 2288 2396Standard: 72b 4 Ps inj, 12 SPS inj 2748 2736 2452 2524

LHC Injection to Collisions

• 5% intensity loss assumed

• 20% emittance blow-up budget, implies:• Control of the additive sources of blow-up• Control of the blow-up due to electron clouds (successful scrubbing in the dipoles)• Impedance reduction with metallic collimators

SPS Extraction LHC collision (min. value – IBS)

LHC collision

Bunch population

[1011]

Emittance[mm]

Emittance (H/V)[mm]

Bunch population

[1011]

Emittance (H/V)[mm]

PIC-BCMS 1.45 1.45 1.68/1.45 1.38 1.8/1.8

PIC-Standard 1.45 1.85 2.04/1.85 1.38 2.22/2.22

5

Assumptions for the performance estimates• Average pile-up limit in IP1-5:

• 140 evt per crossing;

• 1.4 evt/mm accepted but 0.7 evt/mm should be the target;

• Burn-off and pile-up estimation based on:

• Assumed visible cross-section: 85 mb;

• Assumed total cross-section: 100 mb;

• Emittance evolution including:

• IBS

• Radiation damping

• Can represent pretty well performance in 2012 (when no instabilites observed). Only unknown lifetime component is >100 h.

6

Fill 2728

2 4 6 8 10 12 14FILL DURATIO N h

0 .3

0 .4

0 .5

0 .6

0 .7

LUMINO S ITY 10 3 4 cm 2 s 1

IP 1

IP 1 M EA S U R E D

IP 5

IP 5 M EA S U R E D

2 4 6 8 10 12 14FILL DURATIO N h 1 .1

1 .2

1 .3

1 .4

1 .5BUNCH PO PULATIO N B1 10 11

M EA S U R E D

E S T IM A T E D

2 4 6 8 10 12 14FILL DURATIO N h 0 .8

1 .0

1 .2

1 .4

1 .6

BUNCH PO PULATIO N B2 10 11

M EA S U R E D

E S T IM A T E D

PIC @ 6.5 TeV (Pile-up limit at 140)

• b*= 40/20 cm could be relaxed to gain aperture and reduce pile-up density (e.g. 50/25 - S. Fartoukh) with little loss in integrated luminosity.

• Required beam-beam separation being finalized (13 sigmas might be preferable with flat beams)

Nb coll

[1011]e*coll

[mm]#

Coll. Bunches

IP1,5

Min b*(xing/sep)

[cm]

B-BSep[s]

Xingangle

[mrad]

Lpeak

[1034 cm-2s-1]

Llev

[1034 cm-2s-1]

Lev.time[h]

Opt. Fill length

[h]

Performance eff. 6 h

fills [%]

Performance eff. opt. fill length

[%]

Avg. Peak-pile-up density

[ev./mm]

Target int.

Lumi[fb-1 /y]

1.38 1.8 2592 40/20 12 308 3.93 - - 6 28.6 28.6 1.32 70

1.38 2.22 2736 40/20 12 342 3.37 - - 7 30.8 30.5 1.1 70

PIC @ 6.5 TeV (Pile-up limit at 40)Nb coll

[1011]e*coll

[mm]#

Coll. Bunches

IP1,5

Min b*(xing/sep)

[cm]

B-BSep[s]

Xingangle

[mrad]

Lpeak

[1034 cm-2s-1]

Llev

[1034 cm-2s-1]

Lev.time[h]

Opt. Fill length

[h]

Performance eff. 6 h

fills [%]

Performance eff.

opt. fill length

[%]

Avg. Peak-pile-

up density

[ev./mm]

Target int.

Lumi[fb-1/y]

1.38 1.8 2592 40/20 12 308 3.93 1.37 14.5 16.5 55.4 44.3 0.55 70

1.38 2.22 2736 40/20 12 342 3.37 1.45 13.3 15.6 52.5 42.4 0.55 70

9

Some Conclusions• Significant margin: possibility to produce up to

120 fb-1/year but

• Pile-up is the stronger limitation for the performance

• BCMS and Standard production schemes give similar performance