Session 7: I-LHCOrganization:

Chamonix Summary Session7; 10.2.2006 Oliver Brüning 1

-session organized in collaboration with D. Manglunki and all speakers

-6 sessions with main focus on the main project milestones in 2005 and beyond, the key achievements and challenges experienced during the commissioning in 2005, the gained experience with the controls system during the 2005 operations and an outlook for what is still planned for the 2006 run

-all speakers where given a list key questions to be addressed

what can be learned for the LHC commissioning? what still needs to be done for the LHC Pb operation? how does the injector commissionig plan affect the start-up of Pb collisions in the LHC?

1) I-LHC Project overview by Stephan Maury

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Main Questions: -What has been done in 2005 (source, LEIR)-What has to be done in 2006 (LEIR, PS)-Expected early Pb performance for LHC running

What would be the consequences if the commissioning of the ions in the PS was NOT done in 2006?

Main points from the presentation and discussions: -nominal Pb parameters are not compatible with LHC coll system-performance with early Pb beam parameters: L = 5 1025 cm-2sec-1

-make the absolute minimum changes wrt nominal p-p configuration-not finishing the Pb commissioning in LEIR and the PS will delay the Pb operation in the LHC until 2009

Chamonix Summary Session7; 10.2.2006

2) Experience with the GTS-LHC Ion Source Detlef Küchler

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Main Questions: -Performance summary from 2005 experience and future expectations-Spare parts policy What can be done now to ensure reliable operation in the LHC?

Main points from the presentation and discussions: -performance in 2005 is compatible with early Pb scheme-more studies are required in order to achieve performance required for nominal beam parameters -wish list for spare parts: oven, extraction electrodes and insulator, plasma chamber ( total investment of ca 10k€), new RF source (18GHz) investment of ca 100k€-test stand for future development? not really justifiable (1 MCHF)-demands for new ion species should be given in due time

Chamonix Summary Session7; 10.2.2006

3) LEIR Commissioning Christian Carli

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Main Questions: -Summary of the experience from the LEIR Hardware tests-Summary of the experience from the LEIR beam commissioning

What can be learned for the LHC commissioning?

Main points from the presentation and discussions:

Chamonix Summary Session7; 10.2.2006

-commissioning was a joint effort across several groups and departments (AB-ABP, AB-CO, AB-OP, AT-VAC)-commissioning was successful but too many things were done in parallel (installation + operation with beam + control software development)-more studies are required in order to achieve nominal beam Pb parameters: (nominal cylce & ramp rate, vacuum, beam cooling)

4&5) LEIR Controls Sergio Pasinelli & Marine Gourber-Pace

Oliver Brüning 5

Main Questions: -What were the main difficulties with the new control system from the OP point of view and what could be learned from the CO point of view?

What could be tested for the LHC commissioning and where do we still have unsolved issues?

Main points from the presentation and discussions:

Chamonix Summary Session7; 10.2.2006

-change from GM to FESA, large scale deployment of LSA, OASIS,..-previous tests in TI8 and TT40 were not enough for LEIR run-it was a challenge to deploy LHC developments this early in LEIR-LEIR is between the Linac and PS (both on the old control system)-some key application of the control system were late problems for the operation-control system worked well in the end! -extremely valuable validation, important lessons learned and decisions confirmed -SPS start with the new control system in 2006confirmation of positive results (in the end) of LEIR and further test with LHC type proton beam

6) LEIR Electron Cooling Gerard Tranquile

Oliver Brüning 6

Main Questions: -What were the main goals for the new electron cooler in LEIR?

How far away are we from the required cooling rate for the nominal LHC Pb beam and what still needs to be done in 2006?Main points from the presentation and discussions:

Chamonix Summary Session7; 10.2.2006

-Electron cooler construction & pre-commissioning successfully carried out by BINP

-Integration into LEIR (magnetic system readjusted after delivery at CERN, electrical and water connections, commissioning of power supplies, Faraday cage installation, interlock system, UHV preparations, vacuum bakeout) in June-Cooler commissioning started in October (stable 400 mA electron beam obtained,

collection efficiency of 99.96%, static vacuum of 6x10-12 torr)-No clear signal of beam cooling yet (for the time being)-2006: replace electron gun & clear demonstration of cooling

Summary

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Pb physics run at end of 2008 requires Pb operation in the injectors in 2006

Chamonix Summary Session7; 10.2.2006

Pb physics run currently only possible with ‘early’ ion scheme

spare part policy for Pb source identified with help of ‘05 run

commissioning LEIR with new control system was painfulbut it provided important validation for LHC system

still a lot of Pb commissioning studies planned for ‘06 run

LEIR ‘06 run should be smoother SPS start-up

Ions Schedule (options)

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

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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