CERN: Ion and proton particles from CERN's Super Proton Synchrotron (SPS) were successfully injected into the Large Hadron Collider last weekend (23-25 October). It was the first time since September last year that particles were injected into the LHC.
The first ion beam entering point 2 of the LHC, just before the ALICE detector (23 October 2009. Image credit: CERN)
The particles did not travel along the whole circumference of the LHC because CERN is cautiously testing the new quench system—which will protect the magnets from similar damage to that experienced last year.
The LHC will operate at 450 GeV per beam when the machine becomes operational on 23 November, and eventually ramp up to 1.1 TeV per beam in December.
Using lower energies requires less current in the superconducting magnets and will get CERN some experience with the new safeguards before increasing the power output next year to 3.5 TeV per beam in February.
As Peter Woit at Columbia University points out on his blog.
This means that 2009 will not see physics collisions, but will perhaps see collisions at energies marginally higher than that of the Tevatron...
Meanwhile the Department of Energy is requesting extra funds for the Tevatron to keep the collider running through 2011.
Related Physics Today articles
Mostly recovered, the LHC readies for restart October 2009
Mishap shuts down LHC until April November 2008
Multiple problems push LHC start to next spring September 2007
Article modified on 11/09/2009 to provide correct attribution of quote to Peter Woit.
You say that collisions at 900 GeV and at 2.2 TeV are not 'physics collisions'. I beg to differ. I'm planning to do a lot of physics with them. There are important outstanding questions, unresolved discrepancies between, e.g., UA5 and E735 over the entire energy range measured by UA5, which just a few days of measurements at this energy with modern detectors could help resolve. Also, basic measurements over as wide a range of energies as possible with the LHC detectors is crucial to validating and improving our physics models, since different phenomena scale differently with energy - measurements at several energies are more constraining than measurements at only one energy. Physics is what you make it.
Happy for succes of first new LHC test.
Looking forward for more latest news of this great experiment.
Comic on the Higgs Boson, anyone?
http://invisibules.org/comic/25-seeking