LHC Technical Committee 6

07/06/18 K.Schindl

LHC Technical Board 9.4.2002: Summary Lyn’s Opening Remarks:  External Review Committee positive about LHC project but challenge mechanism to monitor project resources and progress  ERC asking for cost to completion of LHC in rather detailed work packages (budget, manpower, Ind. Services per year)  Loan 350 MCHF to CERN for LHC not a problem say the banks  Swiss advance payment 90 MCHF saves ~25 MCHF in interests. LHC Civil Engineering (J.L. Baldy) – Good Progress  UA1 underground: Excavation of the 40 m high UX15 cavern (vault suspended on cables) almost finished.  UA5 underground: Caverns UXC55, USC55, excavated 70%.  TI2 + TI8: 1/3 concreted. Report on MAC 15/16.3. (LHC Machine Advis. Committee, J. Jowett)  New Chairman Maury Tigner – no open session because  Meeting dealt with project schedule and resources:  New schedule (i.e. start-up spring 2007) can be realised, but  Manpower insufficient (e.g. 25 staff in LHC/Magnet group needed)  Recommend adopting “earned value” accounting scheme TCC (Technical Coordination Committee, P. Proudlock)  String 2 (~100 m LHC, 6 dipoles + one quadrupole) ready in June. Test programme will be limited to the absolutely essential issues.  LHC Technical Coordination to be reinforced before Jan 2003 MARIC (Main Ring Committee, Ph. Lebrun)  Field quality (b3, b5) of first preseries dipole not in specs – remedy found (copper wedge correction, optimised for injection field)  Collimators: low-Z material (C or B, 2 m long) instead of Cu (0.5 m)  SM18 Magnet Test Facility: 2 out of 12 measuring units available, ~50 magnets to be measured in 2002. Can SL/PS/OP staff help later? SC (Specification Committee, Ph. Bryant)  2nd Russian Fund? 60 MCHF value for 30 MCHF paid by CERN (= ”Skrinsky” proposal). 1st Fund: 100 MCHF value for 30 paid.  Total committed LHC project: 2.7 GCHF. Uncommitted 18.5% 07/06/18 K.Schindl

LCC (LHC Commissioning Committee, S. Myers)  LHC start-up 2007: intensity limited to ½ nominal by beam dump: bunch spacing 75 ns but 1.5 x nominal bunch intensity proposed to possibly elude electron cloud effects Special: LCC meeting on Ions  Nominal Pb performance:  Luminosity L = 1027 cm-2s-1  100 ns bunch spacing  7 107 Pb ions/bunch  L lifetime 4.2 h with two experiments (ALICE, CMS)  Luminosity a factor ~2 beyond quench limit of inner triplet, but  Physicists (A. Morsch): Halving L to 5 1026 not very useful because background would dominate the event signals.  Not yet an agreement on the issue of ions other than Pb  LHC beam position monitors need > 3.7 107 Pb ions/bunch – requires > ½ of nominal lead intensity to commission the LHC  SPS limited by space charge: nominal beam yields excessive Q ~ 0.17 (max p-pbar: Q ~ 0.07). Remedies proposed:  eject at maximum PS energy (~6 GeV/u for Pb);  split the bunches in the PS before extraction, thus halving Q;  recombine bunches in SPS at higher energy with 100 MHz system.  Leader of the overall LHC Ion Project being sought.  An overall Ion Design Report (source to collision) required.  I reminded the meeting of the Ion Review (with external reviewers) planned for June 2002.  LHC Ion running-in delayed to 2009?  Could ALICE and CMS start with light (oxygen) ions? What would be the performance in PS complex (asked by Lyn after the meeting)