Anyone who has a box for all kinds of accessories knows that keeping track of small, unrelated parts is difficult. Here are the clips. Do they have to lie here with glue? Or are they in a large box with stationery, which are old TV remotes and dog scissors? It is impossible to remember where all personal belongings are.
Now we know what chaos looks like, and we can sympathize with physicists from the European Organization for Nuclear Research, which is CERN (CERN). CERN scientists control the Large Hadron Collider, also known as the LHC, and even found the Higgs boson. BAK is a large particle accelerator located deep beneath the Swiss countryside. The Higgs Boson is a subatomic particle that will allow scientists to learn more about how matter in the Universe gains mass.
The key word here is subatomic. To say that scientists at CERN are looking at things on a small scale would be a huge understatement. They not only see two protons - subatomic particles in themselves - collide with each other, but also try to track down subatomic debris that fly around during a collision. On the one hand, it may seem that the collider is a kind of accessory box in which tiny and fast moving particles are stored. They are so small that they break up faster than you can find them.
Let's go through the whole process of this decay on the fly to understand what exactly scientists need to track. At the BAK, protons fly along a circular track almost at the speed of light. And they are not just worn at any particular moment. CERN scientists need to deliver a proton beam to the LHC, launching gaseous hydrogen into a duoplasmatron, which knocks electrons out of hydrogen atoms, leaving only protons.
Protons enter LINAC 2, the first accelerator of the LHC. LINAC 2 is a linear accelerator that uses electromagnetic fields to accelerate protons. After the first accelerator, protons move at a rate of 1/3 of light.
Then they enter the booster synchrotron, which consists of four rings. Separate groups of protons pass through each ring - and each time they are accelerated by electric pulses and guided by magnets. After this stage, the protons pick up speed of 91.6 percent of the light and are shot down very tightly to each other.
Then they are thrown into the proton synchrotron - already a more concentrated group. In a proton synchrotron, protons circulate in 628-meter rings at a speed of about 1.2 seconds per circle and gain more than 99.9 percent of the speed of light. From this point on, protons can no longer accelerate; instead, they gain in weight and become heavier. Then they enter a superproton synchrotron, a 7-kilometer ring, where they accelerate even more (and become even harder) and become ready for collisions in the LHC pipes.
Here is a useful picture from RIA Novosti.
There are two vacuum tubes on the tank. One sends a beam of protons in one direction, the other - in another. Nevertheless, there are detectors on the four sides of the 27-kilometer LHC, where the beams intersect and where the magic of the collision takes place. Clash creates chaos.
Cool, you think. "Cool Story" about particle acceleration. But how do physicists know where particles are in an accelerator? And how do they track collisions to study them?
Magnets. Magnets around the head.
To be fair, this is only the answer to the first question. Giant cooled magnets keep particles on the right track. Magnets become superconductors at very low temperatures — colder than the cosmos itself. When superconducting magnets create a strong magnetic field that holds the particles in the LHC and eventually causes them to collide.
How do scientists track particles that are the result of a collision? In hot pursuit". Watching the collisions, physicists do not see them on the big screens with Hollywood special effects - they see only the data. Particles that are tracked after a collision are nothing more than traces of data that need to be analyzed.
One of the detectors is actually called tracking, and it allows physicists to “see” the paths of particles after a collision. They see a graphic representation of the path of the particle. As the particles pass through the tracking detector, electrical signals are recorded and then transferred to a computer model. Calorimeter detectors stop and absorb particles in order to measure their energy, their radiation is used to further measure energy and mass, thereby allowing the search to be narrowed for each particular particle.
In fact, this is how scientists tracked particles when the LHC last worked. But we missed that although billions of collisions occur in a second, not all collisions of protons are of interest to scientists. Scientists need a way to sort out useful collisions from boring ones. Here, detectors help them: they pick up interesting particles, and then pass them through an algorithm to see how interesting they are. If particles need to be thoroughly studied, scientists are accepted for them.
When the LHC starts working again in 2015, there will be twice as many collisions (and twice as much collision energy). Well, we look forward to it.
The article is based on materials .
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