I-LHC Project Overview and Status

Chamonix XV, 23-27 Jan. 2006 I-LHC Project Overview and Status Stephan Maury for I-LHC team

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I-LHC Project Overview and Status

Ion Injector Chain – Reminder of Key Parameters

Why an “early beam” ?

Status of :

- Source (talk D. Kuchler)

- LEIR and ECOOL (talks by C. Carli and G. Tranquille)

PS/SPS/LHC

Tentative Schedule

Summary


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Nominal vs Early Ion Beam in LHC

Parameter Units Nominal Early Beam

Energy per nucleon TeV/n 2.76 2.76

Initial Luminosity L0 cm-2 s-1 1 1027 5 1025

# bunches/bunch harmonic 592/891 62/66

Bunch spacing ns 99.8 1350

b* m 0.5 (same as p) 1.0

Number of Pb ions/bunch 7 107 7 107

Transv. norm. rms emittance mm 1.5 1.5

Longitudinal emittance eVs/charge 2.5 2.5

Luminosity half-life (1,2,3 expts.) h 8,4.5,3 14,7.5,5.5

Why Early Beam? much easier for injectors (Linac3, LEIR, PS), shorter LHC filling time (4’/ring)Keep nominal bunch population (7 107 ions/bunch) to study limitations without risksA Luminosity of L=5 1025 cm-2 s-1 (lower by a factor 20) by fewer bunches (1/10) and * =1 m (factor 1/2) useful for physics (early results) improved Luminosity lifetime because of larger *


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Pb Ions for LHC: Hardware Upgrades

Pb27+

Pb54+

LEIR

Repetition rate 1 5 Hz New power converters RF upgrade to 5 Hz

Repetition rate 1 5 Hz New power converters RF upgrade to 5 Hz

Energy ramping cavity Dp/p ~ 0.4%

Energy ramping cavity Dp/p ~ 0.4%

Bi-directional injection/transf. Line Multiturn injection (transverse+longit.) Powerful electron cooling Dynamic UHV by NEG, Collimators RF cavities with frequency “swing” ~8

Bi-directional injection/transf. Line Multiturn injection (transverse+longit.) Powerful electron cooling Dynamic UHV by NEG, Collimators RF cavities with frequency “swing” ~8 New injection

equipment RF hardware

New injection equipment RF hardware

Al Stripper Pb54+ to Pb82+: low-beta insertion

Al Stripper Pb54+ to Pb82+: low-beta insertion

New rf low level hardware for synchronization and acceleration

New rf low level hardware for synchronization and acceleration

200 eA Pb27+: New 14.5 GHz source from CEA Grenoble

200 eA Pb27+: New 14.5 GHz source from CEA Grenoble


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LEIR Acceleration Cycle

Expected Cycle for Lead Ions

0

500

1000

1500

2000

2500

3000

3500

0 500 1000 1500 2000 2500 3000 3500

t[ms]

I[A

]

0.0

0.2

0.4

0.6

0.8

1.0

1.2

B[T

]

Main dipole Current[A]

injection

Main dipole field[T]

Acceleration

Extraction

Electron cooling

4.2 MeV/u

72 MeV/u

Early beam


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Commissioning Pb-Pb in the PS Ring

• Injection Septum (SMH26): Installation and test completed by end of March

• Injection Kicker: Installation and test completed by end of March

• 2 bumpers: - Magnets will be installed before the end of January

- Power supply already installed - tests foreseen in March

• rf: Installation completed by the end of March


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0%

2%

4%

6%

8%

10%

12%

-1.2% -0.8% -0.4% 0.0% 0.4% 0.8% 1.2%

Expected emittance growth due to

stripping 0.12 m (17%)

Final emittance <1.0 m

Ion and proton beam emittance blow-ups in TT2

6 individual supplies (2 quads disconnected from

strings)

6 individual supplies (2 quads disconnected from

strings)

Stripper: lowered by 5

4 new quadrupoles

QNO01-QNO04

For proton beams the 4 new (ion) quadrupoles QNO01 to

QNO04 must get zero gradients for perfect

matching between TT2 and SPSRelative emittance growth in SPS due to

betatron and dispersion mismatches vs relative quadrupole gradient errors (w.r.t. max gradient

value achievable)

ΔH/

H ΔDH/D

H

ΔV/

V ΔDV/D

V

Residual field 0.1% gradient errors emittance growth

0.1%


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Commissioning Pb-Pb in the SPS Ring

• Use TWC 200 MHz and part of the beam control already used for the fixed target ion operation with at least 2 main differences:

- bunch to bucket transfer at injection (injection phase errors are critical)

- new hardware is needed for the synchronization at flat top for extraction to LHC

• Manpower for the beam control upgrade is about 1 m.y


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Commissioning Pb-Pb in the LHC Main Rings

• Refer to detailed plan presented in Chamonix 2005• Basic principle: Make the absolute minimum of

changes to the working p-p configuration– Magnetically identical transfer, injection, ramp, squeeze of IP1,

IP5– Same beam sizes– Different RF frequency swing, add squeeze of IP2

• Requirements– Ion injector chain ready with Early Beam– Minimum instrumentation for ions set up

• Need ionization profile monitors


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How long will it take to commission Pb ions in LHC?

• This will be done when the LHC is already operational with protons

• There is previous experience of switching a hadron collider from one species to another.– RHIC changed a few times, typically from ions to p-p, with 1

week setup + 1 week performance “ramp-up”• More complicated optics changes than LHC (injection is below

transition with ions, above with protons) • Protons are polarized

– Done a few times with the first ion collider at CERN• More directly comparable with LHC ?


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Why did it go so smoothly ?

Previous colliding-beam species switches at CERN


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Factoring in ¼ century of progress in computing, the switchover in the LHC should be achievable in ~1 h.

What about software and system issues ?Yet

another ion in ISR


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Tentative Ion Schedule (Early Beam)

hardware test

Start with beam

Problems

Source and Linac3

Feb. 2005 March 2005 New source

LEIR injection line March 2005

June 2005

LEIR ring Apr. 2005 Aug. 2005(?)/ Oct.2005

LEIR conversion completed ? Commissioning through winter to March

2006/Apr.2006

PS/TT2 Feb. 2006 Sept. 2006 April-August 2006: No LEIR operators (AD)

SPS spring 2007 SPS experts busy commissioning LHC ring in 2007

LHC from April 2008(?)

Physics with the early beam in LHC


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Summary Pb Injectors

Higher performance ECR source can now produce lead ions

LEIR beam commissioning has made good progress

PS Injection systems will be installed and ready for the end of March

New rf hardware (beam control for the nominal beam) will be installed in the PS for the end of March

Four new quadrupoles are installed in TT2 and ready for tests

So, all the hardware in the PS and TT2 will be installed and tested by the end of March 2006

New synchronization hardware for injection and acceleration will be installed in the SPS (need some attention for 1 m.y)


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Summary for LHC Main Rings

• Early Ion Scheme to be scheduled – Switchover from p-p should be possible in 1 week (if ion

injection available at the right time)

• Performance limits for Nominal Scheme to be clarified with Early Scheme, in particular:– Test understanding of BFPP and quenches

– Test understanding of losses from collimation • After Early Scheme Run, increase number of bunches

towards Nominal and complete first phase of LHC ion programme


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Summary I-LHC Project

• Early Beam is just the beginning and opens the door to the Nominal Beam

• Project Schedule: Pb in LEIR until the end of April 2006, PS as from Sept 2006, SPS in 2007, LHC in 2008.

• Studies on the nominal beam in the injectors should start in 2007 in LEIR/PS

in order to go forward to the nominal LHC luminosity.

• The reasons to maintain the commissioning schedule for Pb-ion injectors are: - All the hardware (except in SPS) will be operational by the end of March - in 2006 and early 2007, the LHC is not running and it will be easier to

accommodate commissioning periods for the PS and SPS - in 2006, the expected beam time requirements for CNGS is less

demanding in protons as this year is not a standard year


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Ions Schedule (options)

I-LHC Project Overview and Status

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