Huge Particle Collider Hits Data Milestone

[n2doc]

Clara Moskowitz, LiveScience Senior WriterDate: 17 June 2011 Time: 03:44 PM ET


We'll have to take physicists' word for it that "one inverse femtobarn" is a lot. That's the milestone recently reached by the world's largest atom smasher, the Large Hadron Collider.

Inside the circular machine, which is buried 574 feet (175 meters) underground near Geneva, Switzerland, scientists accelerate protons to speeds approaching that of light, and then crash them into each other to produce energetic wrecks that can give rise to new and exotic particles.

The Large Hadron Collider (LHC) at the CERN physics lab began operating in 2008, and has been ramping up its power levels and the intensity of its particle beams. Today (June 17) at 4:50 a.m. ET (10:50 a.m. local time), the amount of data accumulated by two LHC experiments called ATLAS and CMS clicked over from 0.999 to 1 inverse femtobarn.

A "barn" is a unit of area, approximately equal to the cross-sectional area of the nucleus of a uranium atom. The prefix "femto" means 10⁻¹⁵ or 0.000000000000001, and an inverse femtobarn is a measurement of particle collisions per area — in other words, how many atoms actually smash together inside the machine.

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http://www.livescience.com/14666-large-hadron-collider-data-milestone.html

[Ready4Change]

1. Wow. That many collisions?

I think they should install a traffic light or something. That's ridiculous!

:)

[Terry in Austin]

2. Why do they collide particles with each other?

A stationary target would provide as much "smash," apparently.

Got to wondering about this after seeing a demo on, well, okay, on "Mythbusters": the damage to each of two cars run head on was the same as if each were run into a wall at the same speed. Totally did not expect that!

[n2doc]

3. I think the resulting data is simpler

If you collide with a target, then there are layers of atoms that the beam will collide with.

Also, the energy in the beam is such that a stationary target would get burned through quickly. The beam has enough energy to burn through feet of copper nearly instantaneously.

[Terry in Austin]

4. Interesting -- thanks! -nt