That's okay, fine.
So this is a bit wide subject.
So I will speak a bit about accelerators.
And more or so,
not slides about how RF is used in accelerators.
And then the core of the presentation
would be about how we use right how big
to distribute audio frequency.
So particular accelerators.
Probably you all know about this formula.
Where the main point is that this is a very large factor.
So there is an equivalence between mass and energy.
And very small mass can create a lot of energy.
And this is what we use in atomic plants.
So we create a lot of electricity from very small mass.
What we do at a certain is exactly the opposite.
So we take a lot of energy and we create
in a very non-optimized way,
a very small amount of matter.
And this matter is, I would say,
a little bit random, but we can,
by observing this matter,
we can try to undo physics.
And we can try to understand it a bit more
the lower of the physics.
So how do we get, how do we get this energy?
This energy to create matter.
So you need energy.
It should be very concentrated.
So it will create any mass.
And the easiest way to concentrate a lot of energy
is using kinetic energy and to transfer
where to concentrate using small particles.
This energy.
So you need to accelerate particles.
And Einstein also had because this factor can go,
can be very, very high.
So we need to accelerate particles.
And how do we do that?
You think it's different, low and slow,
which gives you the,
which said that you can have a strength using
his electric field or a magnetic field.
There is something interesting here,
is the speed of the,
in our case of the particle.
And if the speed is very high,
you can have also a nice factor.
Unfortunately, because it's a vectorial product,
you cannot accelerate any object using a magnetic field.
However, you can still use it to steer or to change
the direction of an object.
So we need, in any case, an electric field
to accelerate a particle.
And we use a magnetic field to steer the particle.
You have some, I would say, particle limits.
For example, the magnetic field is an electric field.
It's an electric field.
It's something which is a particle limit of our,
our contact energy.
So in accelerators, you can find RF cavities,
which are the way that electric field is applied
on the beam.
So the beam goes through the cavity
and is being accelerated.
And you have a lot of magnet
around the accelerators.
So here you have the inside this pipe,
which is what you call the chamber.
Like you can chamber.
So the particle goes through the pipe.
And you have many, many magnets around the pipes
to curve the beam.
Also for focusing and focusing.
You have many two main topologies of accelerators.
So the most classical one is linear accelerators,
which is, I would say,
it's a bit simpler and is still used.
The main problem is that you need to accelerate
for a long time.
Well, for a long time,
the gradient of the x-axis feed is limited.
Also it's not a very efficient topology,
because the particle goes only once through every element.
So you need to develop structure only
for a very few small amount of time.
Every structure will be used only
at a very small amount of time by every particle.
That's the main, well, the first topology.
So in order to be able to away use every element,
there is a simple idea of doing a circular accelerator.
So like this, we can see it goes all around.
It's not exactly a circuit,
but you see how it is being made at least closed.
So the main advantage is that you will use every element of the accelerator.
So the beam can stay for a very long time
inside this kind of accelerator.
The main issue is that it's a bit,
it's a more complex topology.
So you have to steer correctly the beam,
so that it comes back at the same point.
And you suffer also from synchronous effect,
which is a low of physics.
So each time you accelerate a particle,
it emits some photon.
So it lose some energy.
And this is a particular tool for electron,
and much less for a photon.
Because it's a low dependent on the weight of the particle,
power, power, power, power.
So for circular accelerators,
one of the main problems is to keep the beam inside this,
here for L.S.E.S.R.T,
which is about 5 cm,
so it's quite small.
And for L.S.R.T, for example, the circumference of the accelerator
is about 27 cm, so you need to be quite precise.
If you don't, it's very simple.
Due to the energy of the beam,
it will do it all in the accelerator,
so it's a valid factor.
So to steer the beam, we use magnetic fields,
and the magnetic field, due to the low physics,
the faster the particle is,
the stronger the magnetic field should be.
So you need to synchronize very precisely the magnetic field,
with the speed of the particle.
And hence, this is the name of the electron,
because you synchronize the magnetic field
and the energy of the beam.
So this is that says the main channel of accelerators.
What do we, what can we accelerate?
So particles and the easiest one will be electron,
because it's very easy to produce,
but the advantage is it's very light,
so it's very subject to synchronization.
If you curve an electron,
if you accelerate it,
it will generate a lot of photon,
it will lose a bit of energy, which is problematic.
We can also accelerate protons,
so that we actually do mainly at some for LHC.
It's much heavier, so let's back to synchronization.
I thought it's not an elementary particle,
so it's, you get less precise result from one portal
to a competitor electron.
We can also, and we also accelerate ions,
which are, I would say, heavier,
and it's a bit different kind of application of physics.
We can also accelerate antiparticles,
which is interesting for collision,
because it will create a lot of collision energy,
and you can use, because the charge is opposite of the particle,
you can use the same pipe to make the particle an antiparticle travel.
For LHC, if you remember the pictures,
you have two, we only accelerate proton,
and there are two pipes,
so it's a beam, there are two beams,
which have a little bit of direction.
It's a very quick overview about accelerators,
a lot of subjects you can,
well, collected to accelerators,
like about how we do collision,
how we do the detectors,
all the instruments we have,
along the accelerator to know about
to characterize better the beam.
There is how we inject or inject a beam
from or out of an accelerator.
There are a lot of problems around magnet,
any particular positive magnet,
which are used for LHC.
Vacuum, because all the particles
have in the vacuum chamber,
and there are also a lot of conservation
about safety and security.
So if you are more, if you are
interesting in some of these subjects,
I have a reference at the end of the presentation.
So CERN is not exactly about only LHC,
anyone who has probably heard about LHC,
but in fact we have a lot of different installations,
and for proton everything
start from this smaller,
linear accelerator, which is named
LHC4, and the source at the origin of the proton beam
is a very small bottle of hydrogen,
and I think you can use one bottle,
we need one bottle every year.
In LHC4, LHC4 accelerates up to about
half of the speed of the light.
Then we go to booster, which accelerates a bit more
up to 95%.
Then we go to the proton cyclone,
which accelerates to 99.9% of the speed light.
Then we go to SPS, super proton cyclone,
which I will talk much more about it,
and then goes almost to the speed of the light.
And then there is LHC,
and it's even more almost the speed of the light.
So it's going to be about to speed of the light
minus maybe 10 kilometers per hour.
It's not.
It's a bit more, so it needs about five minutes to fill
LHC, so it's filled by part using the beam
as criteria as before.
Then it's what we call one pup,
so to reach the maximum speed of the amount of energy
we need about 30 minutes.
And then we can do physics or collision during the boat.
And with the maximum 20 hours, when everything goes well,
it's about 20 hours.
So what we're using, what we're operating the LHC,
the user, I said that there are still used for other experiments.
It's mainly fixed target experiments,
so we send the beam against a target.
And it also means that very, very small part of the beam
produced by the extractile, let's say, from the hydrogen bottle
goes to the LHC.
So we're also talking about LHC.
It's for sure our main instrument,
but there are also many, it's used a very small amount of the beam,
and there are also a lot of signal which happens around.
Okay, that's about, let's say, a few words about accelerators.
I didn't explain a lot about, well,
it didn't speak a lot about LHC, right now,
because it's what I'm talking, what I will talk just now.
In order to accelerate particles,
we use what we call RF cavities, so basically the arcade.
It's also a big topic.
There are, there is, so, right off, I can see,
electric fields which are inside these cavities.
And there's a beam, also inside the cavity.
And when everything goes well, the electric fields
gives energy to the beam, so it accelerates the beam.
So as I said, cavities are very complex topic.
The frequency goes from negative to negative.
If you have low frequency, it means you need to have
larger cavities because it depends on the wavelength of the electric field.
And there's a hand if you have high frequency,
it means you have a lot of tolerance constraint on the cavity.
Also, there is a problem of bandwidth.
So the frequency increase with the speed of the beam,
which means you need a certain bandwidth.
And you cannot have, well, it's very difficult to have a cavity
which can tune to a very large, effective bandwidth.
At certain, we use cavities at 400 megawatts for LHC.
200 megawatts for SPS, so which is, et cetera, just before LHC.
And for PS, we have a lot of different cavities.
There are even cavities which you can tune for a wide bandwidth
because they are mechanically adjusted.
I don't know much about that.
So that's a cavity.
And the source of the cavities is generated by what we call
the lower LHF system.
So this is a system which is responsible of giving the frequency to the cavities.
And it's organized around feedback loops.
And to get the feedback, you have pick up inside the cavities.
And close to the cavities to get the phase of the wave.
And also to the phase of the beam.
And in the middle of that, so between LHF control, LHF and cavities,
you have some amplifiers.
So here this is what we part of what is used for SPS.
And this is where we can see that we are talking about high energy physics
because you need a lot of energy to be given to the beam.
And so you can see for example there are some coax cavities.
But it's slightly different from your standard BNC cable.
So this is triode.
And also energy given by your triode are combined.
And then sand into the wave.
To the SPS, through the tunnel.
And in addition, so this is using coax, in addition, we are also depending on the frequency.
And also use a wave guide.
If the frequency is higher.
So for 200 minutes, we use coax.
And for 800 minutes, for example, we can use wave guide.
So this is very important.
I think now I spoke about the beam.
Which is how particle travel inside the vacuum chamber.
But the beam is not exactly continuous.
It's organized by bunches.
So by group of particles.
The main reason for that is because we are using wagio frequency.
It's idealis, you know, is it all waves.
And if you have a continuous presence of particle, at some point it will be,
So for particle, let's say, being here, it will be.
We have a negative field.
So it will have a strength in one direction.
And then there will be a few that are laterators.
It will be positive.
So it will, the strength will be the opposite direction.
So if you try to send a continuous flow of particles, naturally,
it will, it will be, it will be, it will be go by,
goped by, by, by, by, by benches.
And, um, air control.
So we need to closely control the amplitude, you know,
not to know exactly how much we give energy to the, to the beam.
And we also need to very precisely control the phase,
because, um, if, uh, at one point you actually like particle
and then at the next turn, you are not exactly at the right phase,
but maybe before you will change the, uh, you will give,
you might, the, the, the beam, the, this group of particle,
which is not exactly the, what we, what you want to do.
So you need to have a very good whole, uh, phase.
In a different way, you cannot have the group anywhere on the, on the wave,
because you also want to keep the bunch as, as, as, as, as, as possible.
So I think that you want to have a uniform speed, uh, of every particle,
because the particle will see all, on the particle, which is the same, uh,
magnetic field.
And if the magnetic field is, uh, is related as to be synchronized with, uh,
with, uh, energy of the beam.
And if it's not, so even a particle which are, which have two more, uh,
or not enough energy, there will be curved too much or not enough.
And they will go, uh, outside of their orbit and, uh, uh, go to the,
much to the world of the chamber, which is not exactly what we, what you want to, to do.
So the RF is very, uh, a, uh, a, a, a technique or told in order to have a very well defined, uh,
orbit and precisely the control.
So it's a efficiency and safety, for the, at the same time.
This is about RF.
So now we're attaching the, that bit the curves of the, of the discussion, of the top.
What type of it?
So quick-plantation.
Why type of it is a technology we have developed at
certain in order to distribute time,
if I can see, over it and it.
It's open source and let's say it's try to use,
which is a standard technology.
So there is no new instrument or no new component design for that.
What we do is, so you can think it.
You can think about it like a standard network,
but for each switch, we are able to recover the frequency
from the network, so from another switch.
And it's combinatorally, because ethernet is using
cymbals every time, and you can all the transceiver,
all the transceiver, can give you the frequency of the modulation.
And we use this frequency to discipline a local oscillator.
So every switch and every node, as a local oscillator,
was frequency is the same as the master oscillator,
which is how can it be that?
Which source at the end is atomic clock and GPS source.
So that's for frequency.
Of course, when you recover the frequency,
it's a lot of noise of phase noise or jitter.
So we need to clean as much as possible this frequency.
And this is done by a standard techniques about what
we discipline a local oscillator, we use PLL in other
to clean as much as possible as a phase noise.
We also need to keep the phase.
And for that, we have, I would say,
hands the PTP protocol, which is something
also standard.
And we are able to measure the transmission time
between two switches.
So once it has been measured, we know how to,
we know, to compensate the phase of the oscillator,
of the next oscillator, to be exactly a line,
almost exactly a line to its master.
Right now, we are using one gigabit Ethernet,
and we are using optical fiber.
And we can reach a metric claim, and what we achieve,
is a son and a second accuracy, with about
the PMS implementation, a 50-pcon precision.
I would say the nice thing about what type it is,
you can have quite a good accuracy and precision
using a very cost effective material of hardware.
You can do a synchronization using,
you can do, I would say, what's the synchronization
using even cheaper component?
Like standard Raspberry Pi can do something
in the order of Microsoft's gond.
You can do some much better precision,
but it requires a methodology instrument,
which are way more expensive.
So I would say it's quite a nice, sweet point.
Using for electronics.
If you want to know more about what type it,
yeah, yeah, it is a official website.
It's also interesting of how we,
I would say, which type it would stop the ecosystem.
So it's mainly what type it is,
mainly composed of switches like this,
and Android, which are very values,
depending on the objectification.
We used on the fiber, on the other transceivers.
And you can buy switches like this,
they're actually from Pi weight company.
So I would say, everyone, not only we have developed
the technology, but we have also made it easily,
very diverse for anyone.
So, finally, how we use RF for,
how we use the type it's already for RF.
So just before around COVID,
we managed to win over the SPS RF system,
so mostly low-level RF system.
Okay, to decide it before,
obviously, it was planned before COVID.
The previous system was fully analog,
which has some,
by which we carry a very good knowledge of this system
in order to tune it.
And it was also quite, it has a lot of limitation.
What type it was used,
but it was chosen for the, for the new system,
and we had the typed algorithmant.
So good phase with possibility,
less than 13, because second,
which corresponds to one degree of precision
for the efficacy of, of SPS,
and I would say, quite low phase noise.
So this is a new SPS level RF using my type it.
Okay, I want them down to the detail,
so here you have the, what you call the beam,
cavities, and we measure,
we speak up some characteristic of the beam,
also some characteristic of cavities,
and we do some single processing
in order to, to drive, to drive the cavities.
In addition to that, we also,
we also enabled to distribute this RF signal,
but fully digitally, to the board,
and this is something which is quite interesting
because at some, so at any point,
of around the accelerator,
you can know what is the current RF,
which is interesting if you want to observe
a particular bunch.
So you need to have a tick, which is a clock edge.
You would like to have a clock edge at any point around,
so I thought to know when one particular bunch
is passing around, and this is what is possible
with the, with white rabbit.
Before, it's was not possible with high precision,
because we were using just cable,
and cable has a subject to provide your variation,
or whatever you want, and it's not that easy.
So, it's white rabbit, you are also a new possible application.
So, why are you a rabbit?
First, it's a distributed system.
So, we have different components, which are, okay,
close together, but we need all of them to be
precise, disacronized, and this is a purpose of a white rabbit.
And this system is composed of, okay,
it's almost free digital.
So, you still have ADC and DAC for communication.
We also have some other inputs, in particular,
we are interesting in the beef field,
which is measured inside the magnet,
because, as I said before,
we need to precise disacronize energy given to the beam
with a magnetic field.
And the result of this system is mainly the,
what we call the frequency tuning word,
which is a value, which correspond to a frequency.
And this frequency tuning word is timestamp using white rabbit time.
So, we know exactly at any point,
what is, how to reproduce the frequency.
And in this system, white rabbit is used for communication.
So, for example, we transmit the frequency tuning word
on white rabbit, and for synchronization,
because this is a, all this system need to be synchronized,
because we are using timestamp,
and this is the purpose of, of we type it.
So, how we generate, so, finally, we enter into the SDA, SDR word.
How we generate good clock.
So, for white rabbit, it's you for that,
white rabbit doesn't, I would say,
doesn't really help, you need good oscillators.
So, what we use, I think so, so, it's an oscillator,
which is inside oven, so it's something like a small box,
which is heated at constant operator,
to add a very stable oscillator,
and it is disciplined with white rabbits.
By disciplining, well, by tuning it,
it means that you can slightly vary the frequency
of the oscillator using a voltage source.
Then we are using PLL, and we generate the fixed frequency
using a radius.
And this fixed frequency, which is here,
is then modulated by a sine wave generated by the,
by the FPGA from the frequency tuning word.
And then filter, and then we have,
asking as possible, sine wave.
And using white rabbit, we have commands.
So, for this kind of word, we have, we can,
so we see the frequency tuning word
to set this frequency, and we also receive
possible reset to we align the clock.
That's how we do for SPS.
LHE, one slide, one slide.
That's how we are slowly developing the,
I would say, a roughly equivalent system for LHE.
It's a different frequency,
so it will be a slightly different electronics.
Also, we have developed the electronics five, seven years ago,
and many components are not available anymore.
Thank you to some, thanks to some electronics chip provider.
And we have a lower phase noise,
because it's much more LHE's,
we need much more accurate frequency.
We want to send it more PLL,
but we will use the frequency multiplier.
In SPS, every single one, we synchronize every cycle,
so about every, 30 seconds.
We can do that anymore for LHE,
because it will cycle our more than 20 hours.
And we want to still be able to plug,
or to plug a gap in the middle of a cycle,
and to have automatic resetization.
And also, RF, so we need to originate the RF frequency
for experiment, because they tune the detector with the RF,
because they need to precisely trigger detection
when the bunch crosses inside the detector.
So it's working progress.
Not had finished, we are confident, but we will see.
Finally, I'll give you a, okay, if you need to,
if you want to know more about,
I would say any subject that I talk about,
I give you some references.
In particular, if you're interested in about all the technology
of how it works, how it works,
so there is a certain organized accelerator school,
which are one or two weeks long,
so probably not, probably too long,
but the interesting part of all the slides are available.
So there are a lot of voice sources at available,
sort of web about all the topics of accelerators.
And that's all.