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First successful beam at record energy of 6.5 TeV

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Re: First successful beam at record energy of 6.5 TeV

#21
post #20
post #11

So is that more or less than 1.21 gigawatts? ;)

I started some basic calculations in Google to find out what do you mean. So I converted 6.5 TeV to about 1 microjoule, then typed '1.21 GW / 1 uJ' to find out the beam intensity in particles/second, and realized that the first link is the Wikipedia entry for 'DeLorean time machine'.

(And the answer is that it's more than 1.21GW so long as they're sending 1.2x10^15 of them every second.)

Re: First successful beam at record energy of 6.5 TeV

#22

Could someone explain the significance of this, for those of us that don't know?

The LHC just doubled it's power. While only operating at 50% it discovered several new particles including the Higgs Boson. Now that it's nearing 100% they're hoping to discover physics beyond the Standard Model. That could include things like additional spatial dimensions, Dark Matter, microscopic black holes and more. TLDR: Hopefully opening the door for some mind blowing discoveries.

To expand upon what you're saying for the grandparent, what you have is one beam of protons can reach the kinetic energy of 6.5 TeV. They will circulate a second beam at the same energy, and collide them head on. Thus, the "center-of-momentum" energy, that is, the energy involved in a collision of one proton from one beam hitting another from the other beam will be 13 TeV at max. Often times, physicists refer to this energy by the symbol "s".

Basically, energy and mass are interchangeable in some violent reactions (like the ones at the LHC or that released in atomic explosions) as we know because of Einstein. This means that as we increase the energy of these violent collisions, the more energy that is available to be converted into the mass of possible particle products.

It should be noted that it isn't like we add mass to the products like adding snow to a snow ball, it isn't a continuum. It's more like a threshold. If a particle has a mass of 938 MeV, say, we will see it in a collision as a product only if s for that interaction is greater than 938 MeV. In fact, it must be a bit larger than this, because while some energy gets converted to mass, some energy also needs to get converted to energy of motion for these products too. Otherwise, they won't reach our the detectors in our apparatus for us even to see them.

We haven't seen a number of massive particles we think should exist, from a theory called "Supersymmetry". Note that we do not really know from theory what these masses should be, but we need them to exist for our current models of the universe. Our current guess then for why we don't see them is that we just haven't passed their threshold masses sufficiently to create them first and with enough energy after in order to see them.

That's why 6.5 TeV which implies a max s of 13 TeV is important. It's like we've increased the range of our "scan" of particle masses. It means we'll produce more massive particles (if they exist) and more of them in number with sufficient energy to actually see them.

Re: First successful beam at record energy of 6.5 TeV

#23

Earlier quoted context omitted.

What is that a reference to? Google links to here. At first I wondered if it were this (Another World intro, 1991): https://www.youtube.com/watch?v=1j4gO9sR7zs

I think it's a game. It sounds familiar; I was going to ask the same thing!

:) Glad you like it. Yeah, "screaming electrons", "organics in the reactor" -- digital culture is awesome :)

Re: First successful beam at record energy of 6.5 TeV

#25

Earlier quoted context omitted.

The LHC just doubled it's power. While only operating at 50% it discovered several new particles including the Higgs Boson. Now that it's nearing 100% they're hoping to discover physics beyond the Standard Model. That could include things like additional spatial dimensions, Dark Matter, microscopic black holes and more. TLDR: Hopefully opening the door for some mind blowing discoveries.

To expand upon what you're saying for the grandparent, what you have is one beam of protons can reach the kinetic energy of 6.5 TeV. They will circulate a second beam at the same energy, and collide them head on. Thus, the "center-of-momentum" energy, that is, the energy involved in a collision of one proton from one beam hitting another from the other beam will be 13 TeV at max. Often times, physicists refer to this…

This is a great explanation. One other bit I'll add is that the particles they're colliding are protons, which are made of other particles, called quarks. While the protons are colliding with a relative energy of 13TeV (or will be) the actual collision energy depends on the collision angle of the quarks inside the proton. If it's a glancing collision, which it almost always is, the actual collision energy is much lower. In other words, we don't get to make particles w/ masses of 13TeV. The Higgs for reference has a mass of 125 GeV. That's one reason physicist are considering using Muons in future accelerators instead of protons. They're not made of other stuff.

One of my favorite videos on this topic was a Great Courses video by Sean Carroll. Well worth the $40. http://www.thegreatcourses.com/courses/the-higgs-boson-and-b...

Re: First successful beam at record energy of 6.5 TeV

#26
post #13

Weren't they aiming for 7 TeV?

As the training of the LHC magnets takes a long time, it was decided to run at 6.5 TeV per beam in 2015: http://home.web.cern.ch/about/engineering/restarting-lhc-why...

Maybe next year the energy will be increased to 7 TeV.

Re: First successful beam at record energy of 6.5 TeV

#28
post #27
post #24

http://hasthelargehadroncolliderdestroyedtheworldyet.com/

So the script checks if the variable worldHasEnded isn't defined to see if the world isn't destroyed. Hmm....

I guess that's a valid use for a global variable then.

Re: First successful beam at record energy of 6.5 TeV

#29
post #27

Earlier quoted context omitted.

So the script checks if the variable worldHasEnded isn't defined to see if the world isn't destroyed. Hmm....

I guess that's a valid use for a global variable then.

https://www.youtube.com/v/tKdcjJoXeEY

Re: First successful beam at record energy of 6.5 TeV

#30

Could someone explain the significance of this, for those of us that don't know?

The LHC just doubled it's power. While only operating at 50% it discovered several new particles including the Higgs Boson. Now that it's nearing 100% they're hoping to discover physics beyond the Standard Model. That could include things like additional spatial dimensions, Dark Matter, microscopic black holes and more. TLDR: Hopefully opening the door for some mind blowing discoveries.

Microscopic black holes scares me. I once heard (entirely anecdotal - I'd love it if someone more knowledgeable on the subject could comment) they had calculated the probability that the LHC would create a black hole that consumed the Earth. The result was more likely than SHA1-hash collision, and was deemed safe enough to try. Somewhere between humorous and scary.

edit: did some Googling and found some documentation (https://en.wikipedia.org/wiki/Safety_of_high-energy_particle...). It cites an estimated upper limit of 1 in 50 million and references the book in which that estimate is made.

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