Does this scare anyone else?

[AD-15]

No, they were meant to though. Try googling it, plenty of info. They're hoping for a late june start.

[Saracen]

Hey, dont they turn this thing on this month?

Yes and no.

It was scheduled for start-up this month, but then it's been said it's been scheduled for start-up several times. The original planned date, IIRC, was 2005. Current date is estimated to be July ..... but even that it dependent on some existing engineering problems being solved, and even when it is started up, it'll be very tentatively. There'll be several weeks of low-power running even after they get a proton beam in it, or they risk damaging the cryogenics. They have to do a whole series of engineering tests (that trim steering magnet polarity is correct, position readings are in the correct (horizontal/vertical) plane, that the particles are correctly on the desired orbit, and so on). That will take days ..... or weeks. Then they have to accelerate the particles, step at a time, or they risk damaging the cooling for the superconductors. And by this time, they still won't have even turned on the detectors, because to turn them on before things are running properly risks damaging them. And then the detector engineers have to fine tune their gear, and they're dealing with nanosecond triggers.

In other words, the process of "turn on" could take weeks, even a few months, before it's fully operational and they even start to try to detect collisions. And it'll be months after that before we see any science results, because the results will be "boxed" and nobody sees them until a reasonable amount of data has been collected, so don't expect any results until probably late 2009, or even 2010.

I don't have any inside information, but an informed source told me :-

- expect first particles injected hopefully late 2008
- first physics run in 2009
- first physics results late 2009/2010

[acrobat]

I hope it goes horribly wrong and sends everyone back in time 20 years. I'm gunna do everything so much better next time..

[j1979]

maybe they have turned it on and were stuck in groundhog day but, no one realises it.

[Fraz]

Wish I'd seen this thread a bit earlier. I actually work at CERN and am a bonafide particle physicist, and in particular work on the CMS experiment (the big red one). We're in the process of commissioning the detector right now, and in fact have just finished a week's run triggering on several million cosmic ray events, as we don't yet have beam.

In fact, I'm up late, as I've got to finish some code before tomorrow that configures part of the trigger system that has only just been put in place.

Feel free to ask questions.

Oh and Jay - you seem to be very ill-informed on the physics of black holes. Black holes are equally capable of sucking in any type of matter, be it charged or otherwise. Sounds like you are mangling the idea of Hawking radiation to me.

[Fraz]

There'll be several weeks of low-power running even after they get a proton beam in it, or they risk damaging the cryogenics. They have to do a whole series of engineering tests (that trim steering magnet polarity is correct, position readings are in the correct (horizontal/vertical) plane, that the particles are correctly on the desired orbit, and so on). That will take days ..... or weeks. Then they have to accelerate the particles, step at a time, or they risk damaging the cooling for the superconductors. And by this time, they still won't have even turned on the detectors, because to turn them on before things are running properly risks damaging them. And then the detector engineers have to fine tune their gear, and they're dealing with nanosecond triggers.

In other words, the process of "turn on" could take weeks, even a few months,

Be assured Saracen, we really have turned on the detectors already, and are learning their full capabilities! We've had them turned on (piecemeal) since around July 2007. And we have been promised a 10 TeV beam in only a few months. That's only 4 TeV off the full energy of 14 TeV.

[Lee H]

Fraz... can I be the first to ask.....

Do you take a crowbar to work just 'in case' things go a bit "half-life" ?

[pollaxe]

LOL@Lee!

Fraz, that's really interesting to have someone 'on the inside' of this remarkable project. I hope you'll keep us up to date with what's happening from time to time, assuming the mini black holes don't destroy us all!

[TiG]

Fraz, tell us more please

TiG

[Funkstar]

In other words, the process of "turn on" could take weeks, even a few months, before it's fully operational and they even start to try to detect collisions.

Am I the only one who read this in the voice of The Emperor?

[Salazaar]

I'm too busy giggling at the thought of a crowbar in an emergency case marked 'Only for use in event of resonance cascade'.

Fraz, if you don't already have one, you've soooo got to get one!

[steve threlfall]

I'm too busy giggling at the thought of a crowbar in an emergency case marked 'Only for use in event of resonance cascade'.

Fraz, if you don't already have one, you've soooo got to get one!

Im reading a... no, no everything seems to be within acceptable parameters

[Fraz]

Now you mention it, I do often see this strange man with a briefcase walking around on the opposite side of the experiment hall when I'm working underground...

[Saracen]

Be assured Saracen, we really have turned on the detectors already, and are learning their full capabilities! We've had them turned on (piecemeal) since around July 2007. And we have been promised a 10 TeV beam in only a few months. That's only 4 TeV off the full energy of 14 TeV.

That's interesting. As I said, I've no inside knowledge, but the "informed comment" was from a friend who is one of physicists running the Fermi accelerator, and his comments were based on generic knowledge of the technology rather than specifically of the operations of the LHC. I'll pass your comments on, because if he doesn't know, it'll interest him.

Like many others, I'm a complete numpty when it comes to physics ..... but will be watching with interest to see what happens ..... and for the ILC.

[mediaboy]

Y'know... one of my teacher's reckons that this is how the universe began...

Some swiss scientist got bored and drunk at midnight and decided to try out an experiment with a multi-trillionaire machine.

10 seconds later the last particle is dead, and the newest one is begun.

Naturally, it's all blamed on the Swiss.. why is it that they do everything?

[Fraz]

I don't know if this interests anyone, but here is a (very simple) event display picture of a real event we captured and reconstructed of a cosmic muon going into the top of the CMS detector and exiting out the bottom a couple of weeks ago. It's a straight track at the moment because we don't have the 4 Tesla superconducting magnet switched on yet to bend charged particle tracks:



To give some explanation of the above picture, this is an end-on view of the detector, so the beam pipe is going straight into the middle of the picture. Working from the outside into the centre of the picture: the four outer rings made up of the grey rectangles are the muon detector stations, the solid grey ring is the superconducting solenoidal magnet. Inside the magnet are the hadron and and electromagnetic calorimeters, and the dashed lines and thin grey rings at the very centre represent the silicon strip and pixel detectors.

To give you an idea of the chaos that will be occurring in the detector every 25 nanoseconds when we eventually do have the beam switched on, here is a simulated event representation where a top/anti-top quark pair are created by the beam collision:



Not sure of the exact details of the above event, but here is a rough interpretation:

- The gray tube leading to the bottom right hand corner of the picture is the beam pipe.

- The cyan-coloured lines are charged particle tracks detected by the silicon tracker.

- The cylindrical yellow section represents the detector's calorimeters. The small magenta bars inside represent energy deposits in the electromagnetic calorimeter (the "ECAL", which absorbs electrons and photons), and the dark blue bars outside represent energy deposits inside the hadronic calorimeter (the "HCAL").

- So the biggest dark blue bars most likely represent the energy deposits in the hadron calorimeters from top-quark decay products, called b-quark jets. Any cyan-coloured lines outside the yellow cylinder (with those red rectangles around them) represent muons being tracked through the outermost chambers of the detector; these will also likely be top-quark decay products, resulting from the W boson that is created when a top quark decays.

Hope that makes sense