On what will be the new colliders, particles which they will study and what to do with it will be Russia, “Gazeta.ru” said an expert on accelerator technologies from CERN Ezio Todesco.
Collaboration Conference RDMS (Russia and Dubna Member States ), working on the CMS experiment at the Large Hadron Collider (LHC) and is responsible for the construction of several important parts of the detector passes Every year. Conference 2015 in Varna was devoted to discussing the horizons of elementary particle physics, opening with the second starting operating the Large Hadron Collider. Physics and accelerator physicists discussed possible new physics model, traces of which scientists hope to see in the coming year, as well as options for long-term development of the LHC. In addition, the project of the future collider ring – hadron and lepton machines that can be built by the European Organization for Nuclear Research (CERN) in the 100-km tunnel in 2030-ies.
At the same time Russia has not yet been an associate member of CERN. According to the Minister of Education and Science Dmitry Livanov Russia , this will happen before the end of 2015.
– Ezio, tell us what plans the existing CERN Collider – LHC?
– Now we finally start to work on energy close to the project – 13 TeV (design – 14 TeV). In addition, after conducted in 2013-2015 to upgrade when we changed all the problematic connection between superconducting magnets (they caused an accident in 2008, who brought the car out for a year. – “Times”), we enter the planned luminosity – during 2012 we achieved only 75% of the planned luminosity.
This means that the number of collisions of protons, which we are looking for interesting our particles will be a third higher.
With these parameters, we will work until mid-2018, after which the LHC will stop at the eighteen-month upgrade, after which we plan to enter the final collision energy of 14 TeV and luminosity twice the project.
So we will work until the end of 2022, and then stop for 2.5 years to radically improve our car. This collider will be called HL-LHC – High Luminosity LHC, the collision energy will remain the same, and should increase the luminosity of 5-7 (possibly 10) times the nominal. What does it mean? So, we will be able for the year to collect the same amount of data that the current parameters we gather in five years, and have three times better resolution. This project is funded by CERN and is now in the final stages of planning and design, and we start production. This is the horizon that we see for the LHC.
– Do you think that will replace the LHC?
– Yes, of course! The main thing to say, our future plans will very much depend on what we find at the LHC. And fundamentally important answers we will probably get in the coming year – will we see a new physics that it will be for the particles. This will be an important period in terms of technology – we will see how strong we are, if we can achieve stable operation with the highest possible characteristics of such a huge and complex mechanism.
Despite these uncertainties, CERN has already started exploring the possible scenarios after the LHC project.
That is, the overall plan is as follows: now we have our device, we try to get him maximum performance in data collection. After 10 years, we partially rebuilt, the luminosity increases so that we can get 10 times more data. And after 20 years, we are building a new device.
CERN
– What would it be for the accelerator?
– the whole being considered three options. First – Hadron Collider, where the protons collide, as in the LHC. Second – lepton collider, the LHC as a forerunner in its tunnel – LEP, collider of electrons and positrons. And the third possibility, but it is, in my opinion, less interesting – a clash of hadrons and leptons. We are now at the stage of brainstorming and not dismissing any of these possibilities. Which instrument would be in a new large tunnel – we are now speaking about the ring length of 100 km on the site CERN, – shows physics.
Today we can say that we are the most technologically ready for the construction of electron-positron collider. That is, there is no ready-made solutions, it is not a trivial task, but there is an understanding in a realistic time frame to develop the necessary technology.
For the LHC we will really push the technology forward in many aspects, it is a serious challenge. That is why we are now beginning to study for the development of technologies needed for the creation of such an instrument.
– What are the main challenges?
– Small paradox lies in the fact that the accelerator 99% consists of magnets which do not accelerate the particles, and only 1% – directly accelerating. Most magnets produce an electromagnetic field, the bending path of the particle so that it is held in a ring accelerator.
The relationship between energy and the radius of curvature is linear, so if you want to increase your energy, it is necessary to strengthen the magnetic field, or just do not get to keep the particles on this trajectory. It’s like if you turn off the road: Do not go too fast, otherwise you will crash with the road. That is, with an increase in energy needed simultaneously to increase the magnetic field (which is why these devices are called synchrotrons).
Now the LHC we are working with the magnetic field of 8 Tesla – is several orders of magnitude greater than the Earth’s magnetic field . If we want to increase the energy of the collision, we must build a much larger or tunnel (then the radius of curvature becomes larger), or increase the magnetic field. Plans for the future ring Collider (program FCC – Future Circular Collider) – increase energy seven times, twice to ensure an increase in the magnetic field – from 8 to 16 Tesla and three and a half times increase the length of the tunnel – from 27 to 100 km.
16 Tesla – is the upper limit of the superconducting material, which we are studying – stannide triniobiya, Nb 3 Sn. This is one of the first people found superconductors (it opened in 1954), but its use is much more complicated and more expensive than niobium titanate NbTi, which is used by the LHC. Nb 3 Sn hitherto used in NMR, but not in accelerators. Magnets accelerator is much more complicated, and we have to develop these technologies.
– A few years ago, actively discussed the draft of the International Linear Collider. What’s his status right now?
– Yes, it’s true, a few years ago, the discussion around the project were more active – to place his claim and CERN, and Dubna, and a playground in Japan. But now, as a flagship project, the international community tends to a circular accelerator. Nevertheless, ILC – International Linear Collider – can still be built if it would be interested in Japan, as the host country, while other countries can contribute.
– When a decision is made about what will be the future collider?
– relatively soon, the scientific community can not simultaneously move all the directions, I think, by 2018 we will come to a consensus about what the next flagship project. It is understood that when the collider will be built, most of us already will retire, but this is a typical situation for particle physics – the planning horizon of 10-20 years. In the 1970s, people also talked about the accelerators that have built those who came in to replace them.
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