

Particle accelerators: Small really is beautiful - rweba
http://www.economist.com/news/science-and-technology/21588048-fundamental-physics-seems-have-insatiable-appetite-bigger-more

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maaarghk
This is similar to work going on in Scotland:
[http://www.strath.ac.uk/laserfest/thealpha-
xproject/](http://www.strath.ac.uk/laserfest/thealpha-xproject/)
[http://www.strath.ac.uk/impact/turningelectronsintoopportuni...](http://www.strath.ac.uk/impact/turningelectronsintoopportunities/)

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johapers
It might be of interest to see an animation of the process, as found on the
official Stanford page:
[https://www.youtube.com/watch?v=V89qvy8whxY](https://www.youtube.com/watch?v=V89qvy8whxY)

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dalek_cannes
What the Economist article seem to fail to mention: "In the accelerator-on-a-
chip experiments, _electrons are first accelerated to near light-speed in a
conventional accelerator_. Then they are focused into a tiny, half-micron-high
channel within a glass chip just half a millimeter long."

From: Stanford's own article:
[http://news.stanford.edu/news/2013/september/slac-chip-
accel...](http://news.stanford.edu/news/2013/september/slac-chip-
accelerator-092713.html)

~~~
johndevor
From the Economist article: "Dr Byer did still rely on an old-school
accelerator to feed moderately high-speed electrons into his device in the
first place. But lasers could do that job too, as the German team, led by
Peter Hommelhoff, of the Friedrich Alexander University in Erlangen, and John
Breuer, from the Max Planck Institute of Quantum Optics in Garching,
demonstrate in a second paper, just published in Physical Review Letters."

~~~
Patrick_Devine
and also:

"The electrons fed into it were first sped up using a midsized standard
accelerator, so when they arrived at the glass accelerator they were already
travelling at 99.86% of the speed of light, or 60m electron-volts..."

~~~
cnvogel
And again, in the complete nonsensical quest of describing particle energies
by many nines in 99.999999..% of the speed of light, the proper math falls
down, 99.86% c is ~10 MeV, 60 MeV is about 99.996% c, but IT'S COMPLETELY
MEANINGLESS!

Nevertheless...

Here's a handy online-tool to calculate the speed of a particle accellerated
in a electric field (enter 60000 kV to get the values for the 60 MeV
electron):

[http://www.ou.edu/research/electron/bmz5364/calc-
kv.html](http://www.ou.edu/research/electron/bmz5364/calc-kv.html)

Or calculate it yourself: E = E₀ / √( 1 - β²) with E₀ being the rest-energy of
the particle (511 keV in the case of the electron) and β being the velocity
relative to the speed of light.

At 99.86% of the speed of light, an electron will have a total (rest-mass +
acquired energy by accelleration) energy of about 10 MeV:

    
    
        (in python, energies in keV)
        >>> 511. / math.sqrt( 1 - .9986 ** 2 )
        9660.374008193809

~~~
nxpnsv
...and of course to replicate lhc they'd need to reach 3.5 TeV at high
luminosity. let's just say they are not ready for this quite yet...

EDIT: (in 2011, then 4 TeV and next time they run 7 TeV)

