Search found 49 matches
- Mon May 19, 2014 9:10 am
- Forum: The Accelerator
- Topic: Repulsive gravity testing at the LHC?
- Replies: 1
- Views: 5487
Re: Repulsive gravity testing at the LHC?
Interesting idea. I am skeptical although I didn't go through the relativistic physics in detail. However, I can say that he makes a couple of pretty basic errors with regards to the LHC, which leads me to believe that he hasn't discussed the idea with anyone at CERN.
- Wed Dec 12, 2012 3:54 pm
- Forum: The Accelerator
- Topic: Decay film
- Replies: 2
- Views: 8009
Decay film
I think some people here would enjoy Decay (http://www.decayfilm.com/) To be stressed that this is a work of fiction! However there's lots of nice location shots of CERN and it is surprisingly well filmed for an amateur movie (I am referring to the camera-work, not the acting, which is terrible. But...
- Tue May 29, 2012 8:38 am
- Forum: The Accelerator
- Topic: 2012 Events Discussion
- Replies: 100
- Views: 218324
Re: 2012 Events Discussion
Beams just dumped on a 170 pb^-1 fill! Is this a record for the LHC so far? Now filling with a new scheme. Still 1380b, but few more expected bunch pairs at IP 1 and 5, (CMS/ATLAS) and a few less at point 8 (LHCb). Anyone know why the change? Yes a new record as announced here - https://twitter.com...
- Mon May 07, 2012 12:05 pm
- Forum: The Accelerator
- Topic: Protons and Special Relativity
- Replies: 8
- Views: 17201
Re: Protons and Special Relativity
Yes, the mass of the protons certainly increases according to Einstein's equations, and that's why the protons don't speed up very much in the LHC - most of the added energy goes into extra mass, not extra speed. But that is mass not size. According to Special Relativity, a moving object will appear...
- Thu May 03, 2012 8:23 am
- Forum: The Accelerator
- Topic: What's the rf cavity phasing for?
- Replies: 3
- Views: 7633
Re: What's the rf cavity phasing for?
Oh and the extra complication is that the LHC operates 'above transition' meaning that particles with more energy actually take longer to go round - you have to give an extra FORWARDS kick to the leading particles, and a backwards kick / less forwards kick to the trailing particles... accelerators a...
- Thu May 03, 2012 8:21 am
- Forum: The Accelerator
- Topic: What's the rf cavity phasing for?
- Replies: 3
- Views: 7633
Re: What's the rf cavity phasing for?
That's right. The complication is that the beam itself places a 'load' on the cavities which changes the shape of the oscillation slightly. That's why when you increase the intensity you have to tweak the phase of the cavities to allow for the extra 'beam load'.
- Thu Apr 19, 2012 8:04 am
- Forum: The Accelerator
- Topic: Why is there a difference in the Cms and Atlas luminosities?
- Replies: 9
- Views: 15170
Re: Why is there a difference in the Cms and Atlas luminosit
Analysing the van der Meer scans is not straightforwards and it will take some time before the results are known, and the calibration is applied to the luminosity monitors. Even then, ATLAS and CMS may not agree on the calibration. Already last year there was considerable disagreement on the integra...
- Mon Apr 16, 2012 3:05 pm
- Forum: The Accelerator
- Topic: 2012 Events Discussion
- Replies: 100
- Views: 218324
Re: 2012 Events Discussion
There have been more programmed dumps this year so far, not because the machine is better but because the priorities are different. They are trying to increase the intensity back to 1380 bunches. To get there there are a number of milestones to pass and boxes to tick, in order to satisfy the Machine...
- Thu Apr 05, 2012 1:02 pm
- Forum: The Accelerator
- Topic: Yellow Pipes
- Replies: 1
- Views: 5744
Re: Yellow Pipes
They're beam loss monitors (tip: there's a label just behind them!). Specifically, they are ionisation chambers. They work on the same principle as a Geiger counter: a tube of gas is subject to a high voltage (thus the warning signs). When any particles from the beam hit the beam pipe, they create a...
- Fri Jan 27, 2012 9:30 am
- Forum: Portal link and forum suggestions
- Topic: Too many spam-bots
- Replies: 11
- Views: 24454
Too many spam-bots
In the last few months the forums seem to be more and more plagued by spam-bots. Maybe it's just more noticeable it because all the humans are quiet during the LHC tech stop. Obviously [some of] these bots are quite sophisticated and it's hard to think of a way of weeding them out automatically (For...
- Wed Dec 14, 2011 9:35 am
- Forum: Science
- Topic: Higgs could be found before Christmas!
- Replies: 26
- Views: 34445
Re: Higgs could be found before Christmas!
ATLAS asked for 20 fb-1 in order to confirm (that's how much data they would need, if the Higgs is really around 125GeV, to get a 5 sigma discovery) which is at the optimistic end of the 2012 run.
- Fri Nov 25, 2011 9:24 am
- Forum: The Accelerator
- Topic: Possible uses of Higgs Field
- Replies: 1
- Views: 5622
Re: Possible uses of Higgs Field
and hoverboards! The movies promised us hoverboards!
- Fri Nov 18, 2011 1:00 pm
- Forum: Science
- Topic: Neutrinos go faster then light !
- Replies: 109
- Views: 214069
Re: Neutrinos go faster then light !
The so-called refutation by ICARUS is really nothing of the sort. They measured the neutrino energy spread (which had already been measured by OPERA anyway) and found that the neutrinos had not lost energy on their journey. This links back to an earlier 'refutation' by Cohen & Glashow which states t...
- Fri Nov 04, 2011 9:52 am
- Forum: The Accelerator
- Topic: Is MD expected to be 25% completed?
- Replies: 2
- Views: 6200
Re: Is MD expected to be 25% completed?
That's right, the Hubner factor is the ratio of the integrated luminosity actually produced to the thoretically producible maximum. It's much lower than the fraction of time that the machine is running, because it includes time for filling, ramping, squeezing, etc; the effect of the luminosity half-...
- Mon Oct 31, 2011 3:48 pm
- Forum: The Accelerator
- Topic: Half life sems to have increased from 10 to 12.5 hours
- Replies: 1
- Views: 5220
Re: Half life sems to have increased from 10 to 12.5 hours
For the last week or so they were experimenting with main-satellite collisions in the two 'low-luminosity' experiments. In other words, instead of colliding two main bunches, they collide a main bunch with one of the very small 'satellite' bunches, that is, a bunch of particles in a supposedly unocc...