RE: First collisions at the LHC with unprecedented Energy! (Ask a particle physisicis
October 15, 2015 at 4:59 pm
(October 15, 2015 at 4:43 pm)Alex K Wrote:(October 13, 2015 at 7:14 pm)Pyrrho Wrote: Why have there been fewer collisions?
I don't wholly understand all those technical reasons as I'm not a collider physicist, but here is one important factor: The collider lets pairs of little clouds of protons (bunches with 100 billion protons each) cross 20 million times per second. Let this be a fixed number. Now, maybe you can imagine that the frequency with which the protons in those bunches actually hit each other frontally, depends crucially on how focused those bunches are, how narrow. If you imagine two sets of marbles collide, you immediately see that if the they are very dilute in the sideways directions, there will hardly be any collisions.
This means that if anything interferes with the beam of proton bunches which causes it to lose focus, this will reduce the number of proton - proton collisions achieved.
So do you think there is a problem with the machine? A defective part? A misalignment? Perhaps that they have some bit of dirt in there somewhere? Or do you think they have the settings set wrong somewhere? Or are the little devils just being uncooperative? Maybe they are getting tired of you heartless scientists crashing them into each other.
"A wise man ... proportions his belief to the evidence."
— David Hume, An Enquiry Concerning Human Understanding, Section X, Part I.
