Dear All,
Please see the good news - you may not have heard.
Best regards,
Frank
Frank E. Taylor
CERN MIT
ATLAS Collaboration Bldg. 26 - Rm 569
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---------- Forwarded message ----------
Date: Fri, 19 Mar 2010 10:34:23 +0100
From: Rolf Heuer <[log in to unmask]>
To: "cern-personnel (CERN Personnel - Members and Associate Members)"
<[log in to unmask]>
Subject: 3.5 TeV : Patience pays dividends
French version will follow - La version française suivra
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In my message this week, I'd like to congratulate the LHC team in
accelerating two beams to 3.5 TeV in the early hours of this morning. The
timing could not have been better. Coming during a week of CERN Council
meetings, it allowed us to show delegates the great progress we're making.
The occasion also gave us the opportunity to set out again the prudent
step-by-step approach that we're taking to get the LHC up and running, and
it was refreshing to hear one member of the Scientific Policy Committee
declare on Monday that we should never forget that the LHC is not a
turnkey machine.
With the progress the LHC is making, that simple fact would be easy to
overlook. The figures coming back from this first run are already quite
remarkable. In week 10, the LHC's availability for the operators was over
65%: it usually takes a new accelerator years to reach that level of
availability. And over the last few weeks, operation of the LHC at 450 GeV
has become routinely reproducible, which is again a feat that usually
takes a new machine much longer to achieve.
All this augurs very well for the future, but we must not lose sight of
the fact that the LHC is new, and it wasn't bought off the shelf. It is a
state of the art prototype that is pushing the limits of technology across
a wide range of disciplines, and as such it needs to be treated with the
greatest respect. We have recovered well from the incident of 19 September
2008, and are now poised on the threshold of a new era of discovery. But
the legacy of that incident will be with us for some time to come.
As we approached 3.5 TeV, we encountered a phenomenon linked to the
machine protection systems that has obliged us to increase the ramp time
from 15 minutes to around 75. This will only be a temporary solution while
we correct this effect. With a machine like the LHC, this is typical of
the kind of challenge we face through the switch-on phase, and we must be
prepared for others.
Traditionally, CERN has operated its accelerators on an annual cycle,
running for seven to eight months with a four to five month shutdown each
year. With the LHC, things are different. Being a cryogenic machine
operating at very low temperature, the LHC takes about a month to bring up
to room temperature and another month to cool down. A four-month shutdown
as part of an annual cycle no longer makes sense for such a machine.
That's why we decided in Chamonix to move to a longer cycle with longer
periods of operation accompanied by longer shutdown periods when needed.
Only when the repairs and consolidation are complete after the LHC's next
shutdown will we be fully able to consign 19 September 2008 to the history
books.
In the meantime, we can take satisfaction in what we have achieved to
date, while reminding ourselves, as that SPC delegate advised, that we are
breaking new ground technologically as well as scientifically. Our
stepwise approach, agreed by management, the machine and the experiments,
is the only sensible way to proceed. It takes time, but as we've seen this
week, patience pays dividends.
Rolf Heuer
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