Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

Macavity

"What happens if I put my hand in the LHC beam"?

Recommended Posts

The (dreaded) "Man in Pub" asks:  "What happens if I put my hand in the LHC beam"? Perhaps now an old question? Common knowledge? Failure to answer proves "Scientists don't know everything" etc.  :D

http://blogs.discovermagazine.com/badastronomy/2010/09/21/dont-cross-the-lhc-stream/#.UtJ_WNJ_uXg

New one on me. Interesting (reasonable) that many on the video did not have an immediate answer?

Despite indifferent Google translation, you might get some real notions from a more original source?

http://www.eco-pravda.ru/page.php?al=bugorsky_casus  (Beware: A bit "graphic"!):  :o

I do remember people dangling things (not body parts!) in secondary beams (Don't tell 'em, Pike!) - But that was quite a while ago and beam energies... intensities anyway, have increased. Physical damage to fixed targets in the path of primary Proton Beams was well enough known / documented even then.

An interesting calculation for the reader? Overall not a great thing to try in practice! :p

Share this post


Link to post
Share on other sites

An interesting example of how (some) physicists think. Do some back-of-envelope calculations and come up with several widely different answers, when all along there's a living example (Anatoli Bugorski) of someone who effectively did the experiment, albeit at far lower energy. I think the conclusion is that the LHC would make a hole in your hand. Great links - thanks for sharing.

Share this post


Link to post
Share on other sites

Interesting reading, though I hoped somemebody would have said "you turn into the Hulk" :D

Share this post


Link to post
Share on other sites

Beautifully understated: "was involved in an accident with a particle accelerator" :)

Makes it sound like it dropped on his foot or something.

"Oh, sorry chaps.  I've just spilt vodka in the particle accelerator."

James

  • Like 1

Share this post


Link to post
Share on other sites

.... I think the conclusion is that the LHC would make a hole in your hand.

Which sort of time scale would we be talking? Milliseconds? Seconds? Minutes?

Share this post


Link to post
Share on other sites
  What happens if I put my hand in the LHC beam

You get transported into an alternate universe.

Share this post


Link to post
Share on other sites

Which sort of time scale would we be talking? Milliseconds? Seconds? Minutes?

The LHC (colliders in general) have continuously circulating beams of stored particle bunches. If you could access them (In practice, hopefully you can't!) The vacuum in the ring would be destroyed etc. The whole contents of the LHC would impact on the "target"... or elsewhere in VERY short time scale. Basically on a time scale of one "orbit" at the speed of light?  :eek:

In previous generations of *fixed target* experiments, protons were accelerated, in the main "ring", then extracted (by kicker magnets) at peak energy into various "beam lines" over (say) a couple of seconds. The beam could be shared between several targets / experiments switched on and off etc. System were fairly dynamic - Bit like a series of railway sidings with "points", "buffers" etc. Experimental groups can often control local "beam steering" too.   :)

Acceleration / Extraction takes a "cycle" time of a few seconds? I imagine the unfortunate Russian put his head into (what he thought!) an "inactive" beam line. The main ring was in acceleration, then went into extraction mode? Settings changed? Magnets failed? Safety interlocks failed? Who knows?  :o

I found this rather long (pdf format) CERN machine physics lecture. Dating from early days, around page 25(!), you can see some of their controlled experiments of dumping the total contents of the test beams into a copper target etc. Basically, it seems the beam would indeed drill a HOLE through 2m lengths of copper, vaporising the first part and melting deep into the whole length. Much more spectacular than I had thought frankly.  :p

http://indico.cern.ch/getFile.py/access?contribId=7&resId=2&materialId=slides&confId=6238

Some specifications on the standard beam dumps too - These used to empty the LHC beam at the end of normal runs. Large lumps of carbon, surrounded by cooling / concrete radiation shielding... ;)

Edited by Macavity
  • Like 1

Share this post


Link to post
Share on other sites

Thanks for the link Macavity. Amongst other things, p.14 says that the energy stored in the beam is equivalent to 90kg of TNT.  The magnets however store a quantity energy sufficient to heat up and melt 12 tons of copper!!! 

I suppose that if you were rash enough to put your hand in the LHC beam you'd pretty soon take it out again.

Share this post


Link to post
Share on other sites

Some links were from the oddly named: http://www.cernlove.org/blog/ Quirky, but FUN? :p

Aside: Never struck me before, but science journalists find CERN a tad "utilitarian".

Probably explains why they prefer being (paid) TV Scientists or Skeptics... :D

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.