This blog's been lying dormant (very much like the LHC) since its initial beam-on last year. After the media frenzy surrounding the first successful tests on Beam On Day, the LHC has suffered setbacks and months of repairs to bring it back to operational status. Let's recap the timeline thus far:
- 10th of September, 2008: LHC's first beam on event (press release)
- 20th of September, 2008: "event" in sector 3-4 (press release)
- 21st of October, 2008: LHC officially inaugurated (press release)
- 3rd of October, 2008: LHC World Computing Grid officially crunches first data (press release)
- 16th of October, 2008: CERN releases official report on September incident (press release)
- 9th of February, 2009: CERN confirms the new restart date for the LHC (press release)
CERN has confirmed that the LHC will now restart in September 2009, with a brief technical stop during Christmas. This means that CERN will have full results to crunch in the opening months of 2010, and the timescale also makes provisions for the collisions of lead ions for further study as well. From the press release;
In Chamonix there was consensus among all the technical specialists that
the new schedule is tight but realistic.
“The schedule we have now is without a doubt the best for the LHC and for
the physicists waiting for data,” said CERN Director General Rolf Heuer. “It is
cautious, ensuring that all the necessary work is done on the LHC before we
start up, yet it allows physics research to begin this year.”
This new schedule represents a delay of six weeks with respect to the previous schedule, which foresaw the LHC “cold at the beginning of July”. The cause of this delay is due to several factors such as implementation of a new enhanced protection system for the busbar and magnet splices; installation of new pressure-relief valves to reduce the collateral damage in case of a repeat incident; application of more stringent safety constraints; and scheduling constraints associated with helium transfer and storage.
The enhanced protection system measures the electrical resistance in the cable joints (splices) and is much more sensitive than the system existing on 19 September.
The new pressure relief system has been designed in two phases. The first phase involves installation of relief valves on existing vacuum ports in the whole ring. Calculations have shown that in an incident similar to that of 19 September, the collateral damage would be minor with this first phase. The second phase involves adding additional relief valves on all the dipole magnets and would guarantee minor collateral damage (to the interconnects and super-insulation) in all worst cases over the life of the LHC.
The management has decided for 2009 to install the additional relief valves on four of the LHC’s eight sectors, at the same time as repairs in the sector damaged last September and other consolidation work already foreseen. The dipoles in the remaining four sectors will be equipped in 2010.
Stay tuned for more updates, info and tidbits on CERN and the LHC...