Monday, February 9, 2009

Fwd: Update on the LHC start-up plans and schedule

I got this email today. I thought someone out there might enjoy it:
Dear Colleagues,

The CERN Director-General has released a follow-up note on
the Chamonix LHC workshop (see mail distributed last Friday).
The note is copied below in full. Its basic message is that
a plan has been adopted which implies a schedule with first
collisions end of October 2009, followed by a long physics run
until autumn next year. Please read the DG's message below which
gives more details about this plan. The impact of this new LHC
schedule on our own ATLAS plans will be a central topic for the
forthcoming ATLAS Week.

These good news emphasize the first LHC physics to which we
are all looking forward!

Kind regards,

Peter Jenni

Subject: Message from the Director-General on the LHC schedule

The CERN Management today confirmed the restart schedule for the Large
Hadron Collider resulting from the recommendations from the Chamonix
workshop. The new schedule foresees first beams in the LHC at the end
of September this year, with collisions following in late October. A
short technical stop has also been foreseen over the Christmas period.
The LHC will then run through to autumn next year, ensuring that the
experiments have adequate data to carry out their first new physics
analyses and have results to announce in 2010. The new schedule also
permits the possible collisions of lead ions in 2010.

This new schedule represents a delay of 6 weeks with respect to the
previous schedule which foresaw 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.

In Chamonix there was consensus among all the technical specialists
that the new schedule is tight but realistic.

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 (to the
interconnects and super-insulation) would be minor with this first

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. One of the questions discussed in Chamonix was whether to
warm up the whole LHC machine in 2009 so as to complete the installation
of these new pressure relief valves or to perform these modifications
on sectors that were warmed up for other reasons. The Management has
decided for 2009 to install relief valves on the four sectors that were
already foreseen to be warmed up. The dipoles in the remaining four
sectors will be equipped in 2010.

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