CERN

Identification is completed.

Okay, welcome to CERN.

This is in fact the control room for the Atlas experiment.

Atlas is one of the four large experiments now going on at the LHC,

the large hadron collider.

The large hadron collider is a huge ring of 27 kilometers,

and that's an accelerator where we accelerate protons

in two different directions, and then they collide in four points.

We are just above one of those colliding points at the Atlas experiment.

So Atlas is both

a large collaboration of about 3,000 people,

I'm one of them, my name is Pauline Gagnon, I'm Canadian.

I work for an American institute, Indiana University,

and I live here in France, and work in Switzerland,

but that's just about the kind of sociology

that you have with the people here at CERN.

So it's a very mixed background.

On Atlas alone we have people from more than 70 different countries.

There are only 38 countries participating in the experiment,

but since people like me...

I'm Canadian, and I grew up in American institute so then

there are people from different countries working together.

The common language to work is broken English, so everybody speaks it

with their own mistakes and their own accent, and all that.

So but people get along, and we usually get the work done.

All this, though, you may wonder what's the purpose of all this?

Why do we do...

Why do we go to such an extent, so much work?

3,000 people just to build the detector,

and work on it, and analyze the data that comes out of it.

Essentially, it's just to increase the knowledge about what matter is made of.

What is the universe where we live?

What is this place we are in, and where did it come from?

Where is it going?

So it's very fundamental question.

It's nothing that puts food on your plate right away.

The food might come later on, you know, because with research you never know

what will come out of it.

We're going out, and let's see what we find.

It's a bit like mushroom hunts, you know.

You can bring back something that is really good, then you make a good dish,

or you might not come back with anything suitable.

So, I was saying earlier that we have the accelerator

which accelerates the particles,

and then we have the detectors that are there just to detect what comes up.

A detector is just a very fancy camera.

So we take a snapshot of what happens when two protons come into collisions.

All the energy released in the collision then is in one small tiny point,

and it allows you to create a particle, because E equals MC squared.

So the energy that you have put there, you can transform it into mass.

The C squared's just the exchange rate between energy and mass.

So we can create new particles, and study how they behave.

I saw in 1995 there was an opening

at CERN, and LHC was due to start very soon, and so this is why I decided

it could be a good opportunity, and that's why I jumped.

I think it's actually beautiful to be a part

of modern cathedrals building.

That's the way I see it.

It's like being a community with a single aim and a single scope.

And we are producing machines that actually

nobody has built before, like a cathedral.

I'm in charge of the magnets at CERN, everything that has to do with magnets

for the machines, and I arrived at CERN in 1995 after a few years working

for thermonuclear fusion, and I think I was lured there by the adventure

of the LHC, so it was at the beginning of the LHC,

and in fact where we are today is the hole

where we do all the maintenance, the work,

the construction, the reconstruction of the LHC magnets.

We do mostly dipoles here, and we work in quadropoles as well.

So these are the main elements that make up

the superconducting cryostat of the LHC.

Well, magnets are the main mass in an accelerator.

As you've seen, accelerators at CERN, magnets guide particles.

They drive them around on a circular path,

so that they can go back to the real accelerating component, which is a.

But they need to do that thousands of times

and tens of thousands of times a second, like in the LHC.

So the main function of the magnet is to guide the particles back,

so this is what we call dipoles, and they have to focus them onto

the closed orbit of the machine, and this is the quadropole.

In addition to that, the quadropole, they also squeeze the beam

down to the small size, like smaller than a hair in the experimental region.

This is the main function of the magnets.

The video and ideal of the powers and strength,

I think let's start with the electrical power that we're using

because we need electrical power to run the machines.

So CERN is using roughly 160 megawatts

of electrical power to run all these accelerators,

and that's more or less the consumption of a small city like Geneva,

so it requires indeed a lot of power

in spite of the fact that we're using superconductors.

So the LHC by itself uses about 60 megawatts,

and the whole complex before the pre-injectors

use also about 60 megawatts to inject the beam into the LHC.

As to the magnetic field,

to give you a feeling for how strong the magnetic field is,

you should imagine a magnetic field in our magnets of eight tesla,

produces forces.

And these magnets are 15 meters long,

and the forces that you produce on the magnet

are of the order of 350 tons per half magnet.

So 350 tons per meter of magnets

for every half of the magnet.

So it's a lot of weight that needs to be taken

by the very strong structures that we put around them.

This is why the magnets are all encircled

in these very strong structural steel that is keeping them together.

As to the magnetic field itself, so the field nominal is eight tesla.

You can compare that to the magnetic field of the earth,

which you can barely see with a magnetic needle,

so the earth is producing here in Geneva about half a gauss,

and if I compare that to the magnetic field of the LHC,

it is eight tesla.

That's a factor of 100,000 more.

So we're producing in the LHC 100,000 more magnetic field

than we do compared to the magnetic field of the earth.

We are at 90 meters underground between the Jura and the Lake of Geneva,

and this is the cavern of the ATLAS experiment.

It's the biggest experiment in high energy physics we ever built,

so the cavern is huge.

It's 60 meters by 30 meters cavern,

and inside there is a detector at least 7,000 tons.

It's the same weight of the Tour Eiffel in Paris,

and the cavern is fully occupied, in fact, by our detector,

and this is one of the detectors that has measured the expulsion

this year and last year, and now we are in maintenance mode,

so this a period in which we stop, we open the detector, and we work on it.

So the aim of all this is quite varied.

So one of the main aim that this...

The one that you can find on the press is the discovery of the expulsion.

That is, apart from being a particle, it's a mechanism.

It's a field and is the mechanism that gives the mass

to all the other particles, but this is only one of the aims of this detector.

This is a general particles detector,

and can measure several aspects of the nature

and the several aspects of the nature in this very tiny dimensions,

and this very back in time.

The accelerator itself is a time machine,

and going up with energy allows us to go

back in time and to reach just a tiny amount

of time after Big Bang.

The description of the nature as we know today

is at the moment, I would say, quite complete,

especially after the discovery of the expulsions,

but there are many things we don't understand

for which this detector has been built for,

and this, for example, is questions about dark matter,

and, well, there is one very basic question.

That is the difference between the amount of matter and anti-matter,

because all this knowledge, all this building

on knowledge and building of materials tells you that the Big Bang

at the certain moment in time beginning,

and all the matter, all the matter that exists in the universe now

comes from a very small point from where everything expanded in a way,

to give an image.

But to have this...

Find a tiny point with this anonymous amount of energy and matter density,

you must have a way to put those together,

and the only conceivable way you can see about this

is a symmetric way of thinking, in that you must have the same amount

of matter and anti-matter.

And then of course, you can ask yourself so why there is not

myself in antimatter that is destroying me.

So in a way there is a tiny difference between the matter and the anti-matter

that makes all this exist,

and this is certainly a mystery.

There are other mysteries like the amount of dark matter.

We see that if we look...

we can look at this kind of phenomena also in the space,

and we can look at the matter in the space,

and we cannot really compute totally the matter that is in the space.

We can compute it, but we see that there is a deficit,

and there is what we call the dark matter and the dark energy,

that they are not exactly the same thing.

To make this size of universe, and this way, the matter is distributed possible,

and this is certainly a mystery.

Another mystery I would like to give you is

that I explain to you that to the energy

and the time, they are correlated, and the product of the energy and the time

has to give you a constant.

Now if you think for a moment that the time that you aim at is zero,

then to keep this as a constant, the energy has to be infinite.

So there is into this itself a paradox,

and there is something that maybe we cannot approach.

We can do our best, but the time zero is something that is difficult.

What we do, we do in the research sounds a bit strange.

I mean, we in one hand, we want to make

a confirmation or test of our present theory,

and at the same time, we are always looking for something

which I asks destroying our present theory

to go to something, to find something new.

Yeah, you direct to have the explanation

of this Higgs particle.

Yeah, this is...

Yes, I mean, the Higgs mechanism, I have...

This is one of my...

I have been wondering how one can explain correctly

and easily the role of Higgs field

and Higgs mechanism and the Higgs particle.

And this is something which is difficult for me to do.