What principle underlies the operation of the synchrophasotron. Synchrophasotron: what is it, operating principle and description

The whole world knows that in 1957 the USSR launched the world's first artificial Earth satellite. However, few people know that in the same year the Soviet Union began testing the synchrophasotron, which is the progenitor of the modern Large Hadron Collider in Geneva. The article will discuss what a synchrophasotron is and how it works.

Answering the question of what a synchrophasotron is, it should be said that it is a high-tech and science-intensive device that was intended for the study of microcosm. In particular, the idea of ​​the synchrophasotron was as follows: it was necessary, using powerful magnetic fields created by electromagnets, to accelerate a beam of elementary particles (protons) to high speeds, and then direct this beam to a target at rest. From such a collision, protons will have to “break” into pieces. Not far from the target there is a special detector - a bubble chamber. This detector allows one to study their nature and properties using the tracks left by proton parts.

Why was it necessary to build the USSR synchrophasotron? In this scientific experiment, which was classified as "top secret", Soviet scientists tried to find a new source of cheaper and more efficient energy than enriched uranium. Purely scientific goals were also pursued: a deeper study of the nature of nuclear interactions and the world of subatomic particles.

Operating principle of the synchrophasotron

The above description of the tasks facing the synchrophasotron may not seem too difficult to many to implement in practice, but this is not so. Despite the simplicity of the question of what a synchrophasotron is, in order to accelerate protons to the required enormous speeds, electrical voltages of hundreds of billions of volts are needed. Such tensions cannot be created even today. Therefore, it was decided to distribute the energy pumped into protons over time.

The principle of operation of the synchrophasotron was as follows: a beam of protons begins its movement through a ring-shaped tunnel, in some place of this tunnel there are capacitors that create a voltage surge at the moment when the beam of protons flies through them. Thus, at each turn there is a slight acceleration of protons. After the particle beam makes several million revolutions through the synchrophasotron tunnel, the protons will reach the desired speeds and will be directed towards the target.

It is worth noting that the electromagnets used during the acceleration of protons played a guiding role, that is, they determined the trajectory of the beam, but did not participate in its acceleration.

Problems that scientists encountered when conducting experiments

To better understand what a synchrophasotron is and why its creation is a very complex and knowledge-intensive process, one should consider the problems that arise during its operation.

Firstly, the higher the speed of the proton beam, the more mass they begin to have according to Einstein’s famous law. At speeds close to light, the mass of particles becomes so large that to keep them on the desired trajectory, it is necessary to have powerful electromagnets. The larger the size of the synchrophasotron, the larger the magnets that can be installed.

Secondly, the creation of a synchrophasotron was also complicated by the energy losses of the proton beam during their circular acceleration, and the higher the beam speed, the more significant these losses become. It turns out that in order to accelerate the beam to the required gigantic speeds, it is necessary to have enormous powers.

What results were obtained?

Undoubtedly, experiments at the Soviet synchrophasotron made a huge contribution to the development of modern fields of technology. Thus, thanks to these experiments, USSR scientists were able to improve the process of processing used uranium-238 and obtained some interesting data by colliding accelerated ions of different atoms with a target.

The results of experiments at the synchrophasotron are still used to this day in the construction of nuclear power plants, space rockets and robotics. The achievements of Soviet scientific thought were used in the construction of the most powerful synchrophasotron of our time, which is the Large Hadron Collider. The Soviet accelerator itself serves the science of the Russian Federation, being located at the FIAN Institute (Moscow), where it is used as an ion accelerator.

What is a synchrophasotron: the principle of operation and the results obtained - all about traveling to the site

+ electron) is a resonant cyclic accelerator with a constant equilibrium orbit length during the acceleration process. In order for the particles to remain in the same orbit during the acceleration process, both the leading magnetic field and the frequency of the accelerating electric field change. The latter is necessary so that the beam always arrives at the accelerating section in phase with the high-frequency electric field. In the event that the particles are ultrarelativistic, the rotation frequency, for a fixed orbital length, does not change with increasing energy, and the frequency of the RF generator must also remain constant. Such an accelerator is already called a synchrotron.

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An excerpt characterizing the Synchrophasotron

In 1957, the USSR made a scientific and technical breakthrough in several areas: it successfully launched an artificial Earth satellite, and a few months before this event, the synchrophasotron began operating in Dubna. What is it and why is such an installation needed? This issue worried not only the citizens of the USSR at that time, but the whole world. Of course, the scientific community understood what it was, but ordinary citizens were perplexed when they heard this word. Even today, most people do not understand the essence and principle of the synchrophasotron, although they have heard this word more than once. Let's figure out what this device is and what it was used for.

What is a synchrophasotron used for?

This installation was developed to study the microcosm and understand the structure of elementary particles and the laws of their interaction with each other. The method of knowledge itself was extremely simple: break a particle and see what is inside. However, how can you break a proton? For this purpose, a synchrophasotron was created, which accelerates particles and hits them on a target. The latter can be stationary, but in the modern Large Hadron Collider (which is an improved version of the good old synchrophasotron) the target is moving. There, beams of protons move towards each other at great speed and hit each other.

It was believed that this installation would allow for a scientific breakthrough, the discovery of new elements and methods for producing atomic energy from cheap sources that would be more efficient than enriched uranium and would be safer and less harmful to the environment.

Military purposes

Of course, military goals were also pursued. The creation of atomic energy for peaceful purposes is just an excuse for the naive. It is not for nothing that the synchrophasotron project was classified as “Top Secret”, because the construction of this accelerator was carried out as part of the project to create a new atomic bomb. With its help, they wanted to obtain an improved theory of nuclear forces, which is necessary for calculating and creating a bomb. True, everything turned out to be much more complicated, and even today this theory is missing.

What is a synchrophasotron in simple words?

To summarize, this installation is an accelerator of elementary particles, protons in particular. The synchrophasotron consists of a non-magnetic looped tube with a vacuum inside, as well as powerful electromagnets. Alternately, the magnets turn on, guiding charged particles inside the vacuum tube. When they reach maximum speed with the help of accelerators, they are sent to a special target. The protons hit it, break the target itself and break themselves. The fragments fly in different directions and leave marks in the bubble chamber. Using these traces, a group of scientists analyzes their nature.

This was the case before, but modern installations (such as the Large Hadron Collider) use more modern detectors instead of a bubble chamber, which provide more information about proton fragments.

The installation itself is quite complex and high-tech. We can say that the synchrophasotron is a “distant relative” of the modern Large Hadron Collider. In fact, it can be called an analogue of a microscope. Both of these devices are intended for studying the microworld, but the principle of study is different.

More about the device

So, we already know what a synchrophasotron is, and also that here particles are accelerated to enormous speeds. As it turns out, to accelerate protons to enormous speeds, it is necessary to create a potential difference of hundreds of billions of volts. Unfortunately, humanity is unable to do this, so they came up with the idea of ​​accelerating the particles gradually.

In the installation, the particles move in a circle, and at each revolution they are fed with energy, receiving acceleration. And although such replenishment is small, over millions of revolutions you can gain the necessary energy.

The operation of the synchrophasotron is based on this very principle. Elementary particles accelerated to small values ​​are launched into a tunnel where magnets are located. They create a magnetic field perpendicular to the ring. Many people mistakenly believe that these magnets accelerate particles, but this is actually not the case. They only change their trajectory, forcing them to move in a circle, but do not accelerate them. The acceleration itself occurs at certain acceleration intervals.

Particle acceleration

Such an acceleration period is a capacitor to which voltage is applied at a high frequency. By the way, this is the basis of the entire operation of this installation. A beam of protons flies into this capacitor at the moment when the voltage in it is zero. As the particles fly through the capacitor, the voltage has time to increase, which speeds up the particles. On the next circle, this is repeated, since the frequency of the alternating voltage is specially selected equal to the frequency of the particle’s circulation around the ring. Consequently, protons are accelerated synchronously and in phase. Hence the name - synchrophasotron.

By the way, this method of acceleration has a certain beneficial effect. If suddenly a beam of protons flies faster than the required speed, then it flies into the acceleration gap at a negative voltage value, which is why it slows down a little. If the speed of movement is lower, then the effect will be the opposite: the particle receives acceleration and catches up with the main bunch of protons. As a result, a dense and compact beam of particles moves at the same speed.

Problems

Ideally, particles should be accelerated to the highest possible speed. And if protons move faster and faster on each circle, then why can’t they be accelerated to the maximum possible speed? There are several reasons.

First, an increase in energy implies an increase in the mass of particles. Unfortunately, relativistic laws do not allow any element to be accelerated above the speed of light. In a synchrophasotron, the speed of protons almost reaches the speed of light, which greatly increases their mass. As a result, they become difficult to keep in a circular orbit of radius. It has been known since school that the radius of motion of particles in a magnetic field is inversely proportional to mass and directly proportional to the strength of the field. And since the mass of particles increases, the radius must be increased and the magnetic field made stronger. These conditions create limitations in the implementation of conditions for research, since technologies are limited even today. So far it has not been possible to create a field with an induction higher than several teslas. That’s why they make tunnels of great length, because with a large radius, heavy particles at enormous speed can be kept in a magnetic field.

The second problem is motion with acceleration in a circle. It is known that a charge that moves at a certain speed emits energy, that is, loses it. Consequently, particles constantly lose some energy when accelerating, and the higher their speed, the more energy they spend. At some point, an equilibrium occurs between the energy received in the acceleration section and the loss of the same amount of energy per revolution.

Research carried out at the synchrophasotron

Now we understand what principle underlies the operation of the synchrophasotron. It allowed a number of studies and discoveries to be made. In particular, scientists were able to study the properties of accelerated deuterons, the behavior of the quantum structure of nuclei, the interaction of heavy ions with targets, and also develop a technology for recycling uranium-238.

Application of test results

The results obtained in these areas are used today in the construction of spaceships, the design of nuclear power plants, as well as in the development of special equipment and robotics. From all this it follows that the synchrophasotron is a device whose contribution to science is difficult to overestimate.

Conclusion

For 50 years, such installations have served for the benefit of science and are actively used by scientists all over the planet. The previously created synchrophasotron and similar installations (they were created not only in the USSR) are just one link in the chain of evolution. Today, more advanced devices are appearing - nuclotrons, which have enormous energy.

One of the most advanced of these devices is the Large Hadron Collider. In contrast to the action of the synchrophasotron, it collides two beams of particles in opposite directions, as a result of which the energy released from the collision is many times higher than the energy at the synchrophasotron. This opens up opportunities for more accurate study of elementary particles.

Perhaps now you should understand what a synchrophasotron is and why it is needed. This installation allowed us to make a number of discoveries. Today it has been turned into an electron accelerator, and is currently working at the Lebedev Physical Institute.

It took UK parliamentarians only 15 minutes to decide on a government investment of £1 billion in the construction of a synchrophasotron. After that, they heatedly discussed the cost of coffee for one hour, no less, in the parliamentary buffet. And so they decided: they reduced the price by 15%.

It would seem that the tasks are not comparable in complexity at all, and everything, logically, should have happened exactly the opposite. An hour for science, 15 minutes for coffee. But no! As it turned out later, the majority of respectable politicians quickly gave their innermost “for”, having absolutely no idea what a “synchrophasotron” is.

Let us, dear reader, together with you fill this knowledge gap and not be like the scientific short-sightedness of some comrades.

What is a synchrophasotron?

Synchrophasotron is an electronic installation for scientific research - a cyclic accelerator of elementary particles (neutrons, protons, electrons, etc.). It has the shape of a huge ring, weighing more than 36 thousand tons. Its super-powerful magnets and accelerating tubes endow microscopic particles with colossal energy of directed motion. In the depths of the phasotron resonator, at a depth of 14.5 meters, truly fantastic transformations occur at the physical level: for example, a tiny proton receives 20 million electron volts, and a heavy ion receives 5 million eV. And this is only a modest fraction of all the possibilities!

It is thanks to the unique properties of the cyclic accelerator that scientists were able to learn the most intimate secrets of the universe: to study the structure of negligible particles and the physical and chemical processes occurring inside their shells; observe the synthesis reaction with your own eyes; discover the nature of hitherto unknown microscopic objects.

Phasotron marked a new era of scientific research - a territory of research where the microscope was powerless, which even innovating science fiction writers spoke with great caution (their insightful creative flight could not predict the discoveries made!).

History of the synchrophasotron

Initially, accelerators were linear, that is, they did not have a cyclic structure. But soon physicists had to abandon them. The requirements for energy levels increased - more was needed. But the linear design could not cope: theoretical calculations showed that for these values, it must be of incredible length.

• In 1929 American E. Lawrence makes attempts to solve this problem and invents a cyclotron, the prototype of the modern phasotron. The tests are going well. Ten years later, in 1939. Lawrence receives the Nobel Prize.
• In 1938 In the USSR, the talented physicist V.I. Veksler began to actively engage in the issue of creating and improving accelerators. In February 1944 he comes up with a revolutionary idea on how to overcome the energy barrier. Wexler calls his method “autophasing.” Exactly a year later, the same technology was discovered completely independently by E. Macmillan, a scientist from the USA.
• In 1949 in the Soviet Union under the leadership of V.I. Veksler and S.I. Vavilov, a large-scale scientific project is being developed - the creation of a synchrophasotron with a power of 10 billion electron volts. For 8 years, at the Institute of Nuclear Research in the city of Dubno in Ukraine, a group of theoretical physicists, designers and engineers worked painstakingly on the installation. That’s why it is also called the Dubna Synchrophasotron.

The synchrophasotron was put into operation in March 1957, six months before the flight into space of the first artificial Earth satellite.

What research is being carried out at the synchrophasotron?

Wechsler's resonant cyclic accelerator gave rise to a galaxy of outstanding discoveries in many aspects of fundamental physics and, in particular, in some controversial and little-studied problems of Einstein's theory of relativity:

• behavior of the quark structure of nuclei during interaction;
• the formation of cumulative particles as a result of reactions involving nuclei;
• studying the properties of accelerated deuterons;
• interaction of heavy ions with targets (testing the resistance of microcircuits);
• recycling of Uranium-238.

The results obtained in these areas are successfully used in the construction of spaceships, the design of nuclear power plants, the development of robotics and equipment for working in extreme conditions. But the most amazing thing is that a series of studies carried out at the synchrophasotron are bringing scientists ever closer to solving the great mystery of the origin of the Universe.

In 1957, the Soviet Union made a revolutionary scientific breakthrough in two directions at once: in October the first artificial Earth satellite was launched, and a few months earlier, in March, the legendary synchrophasotron, a giant installation for studying the microworld, began operating in Dubna. These two events shocked the whole world, and the words “satellite” and “synchrophasotron” became firmly established in our lives.

The synchrophasotron is a type of charged particle accelerator. The particles in them are accelerated to high speeds and, consequently, to high energies. Based on the results of their collisions with other atomic particles, the structure and properties of matter are judged. The probability of collisions is determined by the intensity of the accelerated particle beam, that is, the number of particles in it, therefore intensity, along with energy, is an important parameter of the accelerator.

The need to create a serious accelerator base in the Soviet Union was announced at the government level in March 1938. A group of researchers from the Leningrad Institute of Physics and Technology (LPTI), led by Academician A.F. Ioffe turned to the Chairman of the Council of People's Commissars of the USSR V.M. Molotov with a letter in which it was proposed to create a technical base for research in the field of the structure of the atomic nucleus. Questions about the structure of the atomic nucleus became one of the central problems of natural science, and the Soviet Union lagged significantly behind in solving them. Thus, if America had at least five cyclotrons, then the Soviet Union had none (the only cyclotron of the Radium Institute of the Academy of Sciences (RIAN), launched in 1937, practically did not work due to design defects). The appeal to Molotov contained a request to create conditions for the completion of the construction of the LPTI cyclotron by January 1, 1939. Work on its creation, which began in 1937, was suspended due to departmental inconsistencies and the cessation of funding.

In November 1938, S.I. Vavilov, in an appeal to the Presidium of the Academy of Sciences, proposed to build the LPTI cyclotron in Moscow and transfer the laboratory of I.V. to the Physics Institute of the Academy of Sciences (FIAN) from LPTI. Kurchatova, who was involved in its creation. Sergei Ivanovich wanted the central laboratory for the study of the atomic nucleus to be located in the same place where the Academy of Sciences was located, that is, in Moscow. However, he was not supported at LPTI. The controversy ended at the end of 1939, when A.F. Ioffe proposed creating three cyclotrons at once. On July 30, 1940, at a meeting of the Presidium of the USSR Academy of Sciences, it was decided to instruct RIAN to retrofit the existing cyclotron this year, FIAN to prepare the necessary materials for the construction of a new powerful cyclotron by October 15, and LFTI to complete the construction of the cyclotron in the first quarter of 1941.

In connection with this decision, the FIAN created the so-called cyclotron team, which included Vladimir Iosifovich Veksler, Sergei Nikolaevich Vernov, Pavel Alekseevich Cherenkov, Leonid Vasilyevich Groshev and Evgeniy Lvovich Feinberg. On September 26, 1940, the Bureau of the Department of Physical and Mathematical Sciences (OPMS) heard information from V.I. Wexler on the design specifications for the cyclotron, approved its main characteristics and construction estimates. The cyclotron was designed to accelerate deuterons to an energy of 50 MeV.

So, we come to the most important thing, to the person who made a significant contribution to the development of physics in our country in those years - Vladimir Iosifovich Veksler. This outstanding physicist will be discussed further.

V. I. Veksler was born in Ukraine in the city of Zhitomir on March 3, 1907. His father died in the First World War.

In 1921, during a period of severe famine and devastation, with great difficulties and without money, Volodya Veksler ended up in hungry pre-NEP Moscow. The teenager finds himself in a commune house established in Khamovniki, in an old mansion abandoned by the owners.

Wexler was distinguished by his interest in physics and practical radio engineering; he himself assembled a detector radio receiver, which in those years was an unusually difficult task, he read a lot, and studied well at school.

After leaving the commune, Wexler retained many of the views and habits he had fostered.
Let us note that the generation to which Vladimir Iosifovich belonged, the overwhelming majority treated the everyday aspects of their lives with complete disdain, but was fanatically interested in scientific, professional and social problems.

Wexler, along with other communards, graduated from a nine-year high school and, together with all the graduates, entered production as a worker, where he worked as an electrician for more than two years.

His thirst for knowledge, love of books and rare intelligence were noticed and in the late 20s the young man received a “Komsomol ticket” to the institute.

When Vladimir Iosifovich graduated from college, another reorganization of higher educational institutions was carried out and their names were changed. It turned out that Wexler entered the Plekhanov Institute of National Economy, and graduated from MPEI (Moscow Energy Institute) and received a qualification as an engineer with a specialty in X-ray technology.

In the same year, he entered the X-ray structural analysis laboratory of the All-Union Electrotechnical Institute in Lefortovo, where Vladimir Iosifovich began his work by building measuring instruments and studying methods for measuring ionizing radiation, i.e. streams of charged particles.

Wexler worked in this laboratory for 6 years, quickly rising from laboratory assistant to manager. Here Wexler’s characteristic “handwriting” as a talented experimental scientist has already appeared. His student, Professor M. S. Rabinovich subsequently wrote in his memoirs about Wexler: “For almost 20 years, he himself assembled and installed various installations he invented, never shying away from any work. This allowed him to see not only the facade, not only its ideological side, but also everything that is hidden behind the final results, behind the accuracy of measurements, behind the shiny cabinets of installations. He spent his entire life learning and relearning. Until the very last years of his life, in the evenings and on vacation, he carefully studied and took notes on theoretical works.”

In September 1937, Wexler moved from the All-Union Electrotechnical Institute to the Physical Institute of the USSR Academy of Sciences named after P. N. Lebedev (FIAN). This was an important event in the life of the scientist.

By this time, Vladimir Iosifovich had already defended his Ph.D. thesis, the topic of which was the design and application of the “proportional amplifiers” he had designed.

At FIAN, Wexler began studying cosmic rays. Unlike A.I. Alikhanov and his colleagues, who took a fancy to the picturesque Mount Aragats in Armenia, Wexler participated in scientific expeditions to Elbrus, and then, later, to the Pamirs - the Roof of the World. Physicists around the world studied streams of high-energy charged particles that could not be obtained in earthly laboratories. Researchers rose closer to the mysterious streams of cosmic radiation.

Even now, cosmic rays occupy an important place in the arsenal of astrophysicists and specialists in high-energy physics, and excitingly interesting theories of their origin are put forward. At the same time, it was simply impossible to obtain particles with such energy for study, and for physicists it was simply necessary to study their interaction with fields and other particles. Already in the thirties, many atomic scientists had a thought: how good it would be to obtain particles of such high “cosmic” energies in the laboratory using reliable instruments for studying subatomic particles, the method of studying which was one - bombardment (as they figuratively used to say and rarely say now) some particles by others. Rutherford discovered the existence of the atomic nucleus by bombarding atoms with powerful projectiles - alpha particles. Nuclear reactions were discovered using the same method. To transform one chemical element into another, it was necessary to change the composition of the nucleus. This was achieved by bombarding nuclei with alpha particles, and now with particles accelerated in powerful accelerators.

After the invasion of Nazi Germany, many physicists immediately became involved in work of military significance. Wexler interrupted his study of cosmic rays and began designing and improving radio equipment for the needs of the front.

At this time, the Physics Institute of the Academy of Sciences, like some other academic institutes, was evacuated to Kazan. Only in 1944 was it possible to organize an expedition to the Pamirs from Kazan, where Wexler’s group was able to continue the research begun in the Caucasus on cosmic rays and nuclear processes caused by high-energy particles. Without considering in detail Wexler's contribution to the study of nuclear processes associated with cosmic rays, to which many years of his work were devoted, we can say that he was very significant and gave many important results. But perhaps most importantly, his study of cosmic rays led him to completely new ideas about particle acceleration. In the mountains, Wexler came up with the idea of ​​building charged particle accelerators to create his own “cosmic rays.”

Since 1944, V.I. Veksler moved to a new area, which occupied the main place in his scientific work. Since that time, Wexler's name has been forever associated with the creation of large "autophasing" accelerators and the development of new acceleration methods.

However, he did not lose interest in cosmic rays and continued to work in this area. Wexler participated in high-mountain scientific expeditions to the Pamirs during 1946-1947. Particles of fantastically high energies that are inaccessible to accelerators are detected in cosmic rays. It was clear to Wexler that the “natural accelerator” of particles up to such high energies cannot be compared with the “creation of human hands.”

Wexler proposed a way out of this impasse in 1944. The author called the new principle by which Wechsler's accelerators operated autophasing.

By this time, a charged particle accelerator of the “cyclotron” type had been created (Weksler, in a popular newspaper article, explained the principle of operation of the cyclotron as follows: “In this device, a charged particle, moving in a magnetic field in a spiral, is continuously accelerated by an alternating electric field. Thanks to this, it is possible to impart an energy of 10-20 million electron volts to the cyclotron.”). But it became clear that the 20 MeV threshold could not be passed using this method.

In a cyclotron, the magnetic field changes cyclically, accelerating charged particles. But in the process of acceleration, the mass of particles increases (as it should be according to SRT - the special theory of relativity). This leads to a disruption of the process - after a certain number of revolutions, the magnetic field, instead of accelerating, begins to slow down the particles.

Wexler proposes to begin to slowly increase the magnetic field in the cyclotron over time, feeding the magnet with alternating current. Then it turns out that, on average, the frequency of rotation of particles in a circle will automatically be maintained equal to the frequency of the electric field applied to the dees (a pair of magnetic systems that bend the path and accelerate the particles with a magnetic field).

With each passage through the slit of the dees, the particles have and additionally receive a different increase in mass (and, accordingly, they receive a different increment of the radius along which the magnetic field turns them) depending on the field voltage between the dees at the moment of acceleration of a given particle. Among all particles, equilibrium (“lucky”) particles can be distinguished. For these particles, the mechanism that automatically maintains the constancy of the orbital period is especially simple.

“Lucky” particles experience an increase in mass and an increase in the radius of the circle each time they pass through the dee slit. It precisely compensates for the decrease in radius caused by the increment in the magnetic field during one revolution. Consequently, “lucky” (equilibrium) particles can be resonantly accelerated as long as the magnetic field increases.

It turned out that almost all other particles have the same ability, only acceleration lasts longer. During the acceleration process, all particles will experience oscillations around the orbital radius of the equilibrium particles. The energy of particles on average will be equal to the energy of equilibrium particles. So, almost all particles participate in resonant acceleration.

If, instead of slowly increasing the magnetic field in the accelerator (cyclotron) over time, feeding the magnet with alternating current, we increase the period of the alternating electric field applied to the dees, then the “autophasing” mode will be established.

“It may seem that in order for autophasing to occur and resonant acceleration to occur, it is necessary to change in time either the magnetic field or the period of the electric one. Actually this is not true. Perhaps the simplest in concept (but far from simple in practical implementation) method of acceleration, established by the author before other methods, can be implemented with a magnetic field constant over time and a constant frequency.”.

In 1955, when Wexler wrote his pamphlet on accelerators, this principle, as the author pointed out, formed the basis of an accelerator - a microtron - an accelerator requiring powerful sources of microwaves. According to Wexler, the microtron “has not yet become widespread (1955). However, several electron accelerators with energies up to 4 MeV have been operating for a number of years.”

Wexler was a brilliant popularizer of physics, but, unfortunately, due to his busy schedule, he rarely published popular articles.

The autophasing principle has shown that it is possible to have a stable phase region and, therefore, it is possible to change the frequency of the accelerating field without fear of leaving the resonant acceleration region. You just need to choose the right acceleration phase. By changing the field frequency it became possible to easily compensate for the change in particle mass. Moreover, changing the frequency allowed the rapidly spinning spiral of the cyclotron to be brought closer to a circle and accelerate the particles until the magnetic field strength was enough to keep the particles in a given orbit.

The described accelerator with autophasing, in which the frequency of the electromagnetic field changes, is called a synchrocyclotron, or phasotron.

The synchrophasotron uses a combination of two autophasing principles. The first of them lies at the heart of the phasotron, which has already been mentioned - this is a change in the frequency of the electromagnetic field. The second principle is used in synchrotrons - here the magnetic field strength changes.

Since the discovery of autophasing, scientists and engineers have begun designing accelerators capable of billions of electron volts. The first of these in our country was a proton accelerator - a 10 billion electron-volt synchrophasotron in Dubna.

The design of this large accelerator began in 1949 on the initiative of V. I. Veksler and S. I. Vavilov, and was put into operation in 1957. The second large accelerator was built in Protvino near Serpukhov with an energy of 70 GeV. Not only Soviet researchers, but also physicists from other countries are now working on it.

But long before the launch of two giant “billion-dollar” accelerators, relativistic particle accelerators were built at the Physical Institute of the Academy of Sciences (FIAN), under the leadership of Wexler. In 1947, an electron accelerator up to energies of 30 MeV was launched, which served as a model of a larger electron accelerator - a synchrotron with an energy of 250 MeV. The synchrotron was launched in 1949. Using these accelerators, researchers at the Physics Institute of the USSR Academy of Sciences carried out first-class work on meson physics and the atomic nucleus.

After the launch of the Dubna synchrophasotron, a period of rapid progress began in the construction of high-energy accelerators. Many accelerators were built and put into operation in the USSR and other countries. These include the already mentioned 70 GeV accelerator in Serpukhov, 50 GeV in Batavia (USA), 35 GeV in Geneva (Switzerland), 35 GeV in California (USA). Currently, the Large Hadron Collider at 14 TeV (teraelectron-volt - 10^12 eV) has been put into operation.

In 1944, when the term "autophasing" was born. Wexler was 37 years old. Wexler turned out to be a gifted organizer of scientific work and the head of a scientific school.

The autophasing method, like a ripe fruit, was waiting for a scientist-seer who would remove it and take possession of it. A year later, independently of Wexler, the principle of autophasing was discovered by the famous American scientist McMilan. He recognized the priority of the Soviet scientist. McMillan met with Wexler more than once. They were very friendly, and the friendship of two remarkable scientists was never overshadowed by anything until Wexler’s death.

Accelerators built in recent years, although based on Wechsler's autophasing principle, are, of course, significantly improved compared to first-generation machines.

In addition to autophasing, Wexler came up with other ideas for particle acceleration that turned out to be very fruitful. These ideas of Wexler are widely developed in the USSR and other countries.

In March 1958, the traditional annual meeting of the USSR Academy of Sciences took place in the House of Scientists on Kropotkinskaya Street. Wexler outlined the idea of ​​a new principle of acceleration, which he called “coherent.” It allows you to accelerate not only individual particles, but also plasma clots consisting of a large number of particles. The "coherent" acceleration method, as Wechsler cautiously said in 1958, allows one to think about the possibility of accelerating particles to energies of a thousand billion electron volts and even higher.

In 1962, Wexler, at the head of a delegation of scientists, flew to Geneva to participate in the International Conference on High Energy Physics. Among the forty members of the Soviet delegation were such prominent physicists as A. I. Alikhanov, N. N. Bogolyubov, D. I. Blokhintsev, I. Ya. Pomeranchuk, M. A. Markov. Many of the scientists on the delegation were accelerator specialists and students of Wexler.

Vladimir Iosifovich Veksler was for a number of years chairman of the Commission on High Energy Physics of the International Union of Theoretical and Applied Physics.

On October 25, 1963, Wexler and his American colleague, Edwin McMillan, director of the Radiation Laboratory at Lawrence University of California, were awarded the American Atoms for Peace Prize.

Wexler was the permanent director of the High Energy Laboratory of the Joint Institute for Nuclear Research in Dubna. Now the street named after him reminds us of Wexler’s stay in this city.

Wexler's research work was concentrated in Dubna for many years. He combined his work at the Joint Institute for Nuclear Research with work at the P. N. Lebedev Physical Institute, where in his distant youth he began his career as a researcher, and was a professor at Moscow State University, where he headed the department.

In 1963, Veksler was elected Academician-Secretary of the Department of Nuclear Physics of the USSR Academy of Sciences and permanently held this important post.

The scientific achievements of V. I. Veksler were highly appreciated by awarding him the State Prize of the First Degree and the Lenin Prize (1959). The outstanding scientific, pedagogical, organizational and social activities of the scientist were awarded three Orders of Lenin, the Order of the Red Banner of Labor and medals of the USSR.

Vladimir Iosifovich Veksler died suddenly on September 20, 1966 from a second heart attack. He was only 59 years old. In life, he always seemed younger than his years, was energetic, active and tireless.