Thursday, March 27, 2008

Under Control: Keeping the LHC Beams on Track

While people do have some idea of the size and the complexity of the LHC, most do not have a good 'scale' of the issues involved here. There are some astounding issues and problems that they have to deal with. Keeping the LHC beam under control, and what to do when it veers off course is a major issue.

This article tries to impart some idea on the control and contingency issues of the LHC beam. For example:

The complexity means that repairs of any damaged equipment will take a long time. For example, it will take about 30 days to change a superconducting magnet. Then there is the question of damage if systems go wrong. The energy stored in the beams and magnets is more than twice the levels of other machines. That accumulated in the beam could, for example, melt 500 kg of copper. All of this means that the LHC machine must be protected at all costs. If an incident occurs during operation, it is critical that it is possible to determine what has happened and trace the cause. Moreover, operation should not resume if the machine is not back in a good working state.

So this is not case where you can just simply pull the switch if something goes wrong. They have to make sure they dump the beam properly without causing damage to all the components along the ring.

This is, of course, a common issue at large particle accelerator facilities, including the Tevatron. I am still at awed at some of the things they are able to do, and at the scale that they are doing in. I some time wish the most of the general public has some clue on the level of complexity and the accomplishments at just being able to run such an experiment.



Anonymous said...

I better keep myself anonymous for this comment. CERN has a collaboration with the University of Auckland for developing the Diamond detectors used for monitoring the beam in case something goes wrong. Sadly however, the "professor" at Auckland is very incompetent. I sure hope there is a committee overseeing his work because if something with the beam does go wrong, I'm not sure how well his system would work! This highlights one of the problems with CERN trying to get as many countries involved, for publicities sake, as possible. Sometimes you get stuck with incompetent people.

ZapperZ said...

Oh dear.

Well, if I know anything about such large scale projects, each piece is usually tested to make sure they are all working properly. I would think that when they fired it up in July, I don't expect them to be running up to specs right away. In project this big, usually one throws away data from the first few months anyway because such run is usually for every component and detector to be tested and calibrated.

So I'm sure this thing will get tested first. If not, then things can get ugly. :)