Maisner condition. Mason Effect and its practical application

Magnet in a superconducting cup with water with liquid nitrogen is ferry as a mugomeset coffin ...

The legendary "Magomet Coffin" fited in the "scientific" picture of the world in 1933 as "Mason Effect": Locked above the superconductor, the magnet searches and starts levitate. Scientific fact. A "Scientific Picture" (i.e., the myth of those who deal with the explanation of scientific facts) is: "A constant not too strong magnetic field is pushed out of the superconducting sample" - and everything immediately became clear and understandable. But those who build their own picture of the world are not allowed to think that he deals with levitation. Who likes what. By the way, the one who is not lucked by the "scientific picture of the world", that in science is more productive. Now we'll talk about this now.

And the case of God, the inventor ...

In general, to observe the "Maissen-Mahomet" effect, it was easily not easy: liquid helium was needed. But in September 1986, when the message of G. Bistza and A. Muller appeared that in ceramic samples based on Ba-La-Cu-O, high-temperature superconductivity is possible. This completely contradicted the "scientific picture of the world" and the guys would quickly emitted with this, but it was "Magomet Coffin": the phenomenon of superconductivity now it was possible to demonstrate anyone and anywhere, and so all other explanations of the "scientific picture of the world" contradicted even more , superconductivity when high temperatures quickly recognized and their Nobel Prize These guys have already received the next year! - Compare with the subject of the theory of superconductivity - Peter Kapitsa, who opened superconductivity fifty years ago, and "Nobelka" received only eight years before these guys ...

Before continuing, admire the levitation of Magomet Maissener on the following video.

Before starting the experience of a superconductor from special ceramics ( YBA 2 Cu 3 O 7) cooled, watering it with liquid nitrogen, so that it acquires its "magic" properties.

In 1992, the University of Tampere (Finland), Russian scientist Yevgeny Plottnov conducted studies of the properties of the shielding with superconducting ceramics of various electromagnetic fields. However, in the process of experiments, it was quite by chance that the effect was found not fit into the framework of classical physics. The tweets called it - "gravity shielding" and, with co-author, published a preliminary message.

The sublock rotated the "frostbitten" superconducting disk in the electromagnetic field. And once, someone in the laboratory lit the tube and smoke, who fell into the zone above the rotating disk, suddenly rushed up! Those. Smoke, walked over the disk in weight! Measurements with objects from other materials were confirmed by a guess, not perpendicular, but in general the opposite "scientific picture of the world": it turned out that it was possible to defend against the "all-pervagrating" forces of the World Communication!
But, in contrast, from the visual effect of Maissen-Mahomet here, the visibility was much lower here: weight loss was a maximum somewhere 2%.

The experiment report was completed by Evgeny Snacktnovy in January 1995 and sent D. Modanese, who asked him to give the name necessary to citation in his work "Theoretical Analysis ..." of the Los Alamos Preprints Library (HEP-TH / 9505094) and the summory theoretical Foundation to experiments. So the Identifier of the MSU - Chem 95 appeared (or in the transcription of Moscow State University - Chemistry is 95 years old).

The article was rejected by several scientific journals, until finally, she was not accepted for publication (for October 1995) in the prestigious "Journal of Physics", published in England (The Journal of Physics-D: AppLied Physics, A Publication Of England »S Institute Physics). It seemed that the discovery was about to provide himself if not recognition, then at least the interest of the scientific world. However, it turned out wrong.

The first article was published far from science editionwho do not dismiss the purity of the "scientific picture of the world" - today will write about green men and flying plates, and tomorrow about anti-gravity - it would be interesting to the reader, it does not matter, this fits or does not fit into the "scientific" picture of the world.
The representative of the University in Tampere said that in the walls of this institution did not deal with the issues of anti-gravity. The collaborators of Levit and Vuorinen, which provided technical support, frightened the scandal, disappeared from the laurels of the laurels, and Evgeny Plottnov was forced to decide the prepared text in the magazine.

However, the curiosity of scientists won. In 1997, NASA Group in Huntsville, Alabama, repeated the pilot experiment using its installation. Static test (without rotation of the hitch) The effect of gravity shielding has not confirmed.

However, otherwise could not:the previously mentioned Italian physicist - theorist Giovanni Modanese, in his report presented in October 1997 at the 48th Congress of IAF (International Astronaut Federation), held in Turin, noted, supported by the theory, the need for use to obtain the effect of a two-layer ceramic HTSC disk With a different critical temperature of the layer (however, he wrote and lined). In the future, this work was developed in the article "Gravitational Anomalies by HTC SuperConductors: A 1999 Theoretical Status Report." By the way, there is also an interesting conclusion, on the impossibility of building aircraft using the effect of "gravity shielding", although there remains the theoretical possibility of building gravitational elevators - "lifts

Soon, gravity variations were discovered by Chinese scientists.during the measurement of gravity change in the process of complete sun Eclipse, very little, but indirectly confirms the possibility of "gravity shielding". So began to change the "scientific" picture of the world, i.e. Create a new myth.

In connection with what happened, it is appropriate to ask the following questions:
- and where were the notorious "scientific predictions" - why science did not predict the anti-gravity effect?
- Why does everything decide the case? Moreover, the armed scientific picture of the world scientists, even after they were worn and put in the mouth, could not repeat the experience? What is this in the case of such that in one head comes, and it is simply not in the other?

Another cool difference russian wrestlers with Lzhenauka, By whom we until the end of their days were led by the militant materialist Yevgeny Ginzburg. Professor from the Institute of Physical Problems. P.L. Kapitsa RAS Maxim Kagan said:
Experiments of the sublock look rather strange. At two recent international conferences on superconductivity in Boston (USA) and Dresden (Germany), where I participated, his experiments were not discussed. It is not widely known to those specialists. Einstein equations, in principle, the interaction of electromagnetic and gravitational fields is allowed. But in order for such an interaction to become noticeable, a colossal electromagnetic energy is needed, comparable to the Einstein revenue energy. We need electrical currents for a lot of orders of magnitude higher than those achievable in modern laboratory conditions. Therefore, we do not have real experimental possibilities to change gravitational interaction.
- What about NAS?
- Nasa has big money for scientific development. They check many ideas. I even check the ideas very dubious, but attractive to the wide audience ... We study the real properties of superconductors ....»

- That's how it is: we are realistic materialists, and there are semi-graphic Americans can be crowned with money to the right and left in favor of fans of the occultism and other lzhenayuki, it is, they are their business.

More details with the work of those who wish can be trained.

Antigravitational Gun Singnyova-Modanese

The scheme of "anti-gravity gun"

I hung out on realistic-compatriots of the sublings in full. Together with the theorist MODASE, they were created, figuratively speaking, an anti-gravity gun.

In the preface to publication of the subcotton, wrote the following: "I am not public work on gravity in Russian, so as not to put in the uncomfortable position of my colleagues and the administration. In our country there are enough other problems, and the science does not interest anyone. You can freely use the text of my publications in competent translation ...
Please do not bind these works with flying plates and aliens, not because they are not, but because it causes a smile and no one wants to finance funny projects. My gravity work is very serious physics and carefully executed experiments .. We operate with the possibility of modifying the local gravitational field based on the theory of vacuum energy fluctuations and quantum gravity theory».

And so, the work of the sublock, in contrast to the Russian henres, did not seem ridiculous, for example, Boeing, which launched extensive studies on this "funny" subject.

And the twelts and modones created a certain device that allows you to manage gravity, more precisely - antigravitation . (Report on the website of the Los Alamos laboratory can be). " Controlled gravitational impulse "allows for a short-term impact effect on any items at a distance of tens and hundreds of kilometers, which makes it possible to create new movement systems in space, communication systems, etc." In the text of the article, it is not striking, but it should be paid to the fact that this impulse repels, and does not attract objects. Apparently, given that the term "gravity shielding" is not acceptable in this case, only the fact that The word "anti-gravity" is "taboo" for science, makes the authors avoid its use in the text.

At a distance of 6 to 150 meters from installation, in another building, measuring were installed.

Vacuum flask with pendulum

devices representing conventional pendulums in vacuum flasks.

For the manufacture of spheres of pendulums, various materials were used: Metal, glass, ceramics, wood, rubber, plastic. The installation was separated from measuring instruments located at a distance of 6 m.- 30 centimeter brick wall and steel sheet 1x1.2x0.025 m. Measuring systems located at a distance of 150 m., were additionally fenced with a brick wall with a thickness of 0.8 m. Not more than five peters were used in the experiment, located on the same line. All their testimony coincided.
To determine the characteristics of the gravitational pulse - in particular its frequency spectrum, a condenser microphone used. The microphone was connected to the computer and was located in a plastic spherical box filled with porous rubber. It was placed on the sighting line after glass cylinders and had the possibility of various orientation to the direction of the discharge axis.
The impulse launched the pendulum that was visually observed. The lagging time began to oscillation of the pendulum was very little and did not measure their own oscillations gradually faded. Technically, it was possible to compare the signal from the discharge and the response received from the microphone, which has the typical behavior of the perfect pulse:
It should be noted that no signal was found outside the field of sight and it seems that the "bundle of strength" had clearly defined boundaries.

The dependence of the impulse force (the angle of deviation of the pendulum) is not only from the discharge voltage, but also from the type of emitter.

The temperature of the pendulum, in the process of experiments has not changed. The force affecting the pendulum did not depend on the material and was proportional to only the mass of the sample (in the experiment from 10 to 50 grams). Pendiles of various masses were demonstrated equal deviation at constant voltage. It was proven large quantity Measurements. Deviations in the strength of the gravitational pulse are also found within the range of the emitter projection (emitter). These deviations (up to 12-15%) are associated with possible emitter inhomogeneities.

Pulse measurements, in the range of 3-6 m, 150 m (and 1200m) from the experimental setup, were given, within the experiment errors, identical results. Since these points of measurements other than air were also separated by a thick brick wall, it can be assumed that the impulse of gravity was not absorbed by the medium (or losses were insignificant). The mechanical energy "absorbed" every pendulum depended on the discharge voltage. Indirect evidence that the observed effect is of gravitational nature is the established fact of the ineffectiveness of electromagnetic shielding. In the gravitational effect, the acceleration of any body experiencing a pulse effect should be in principle, regardless of body weight.

P.S.

I am a skeptic, and I do not really believe that it is generally possible. The fact is that there are completely ridiculous explanations of this phenomenon, including in physical journals, such as the fact that they have so developed back muscles. Why not buttocks?!

AND So: Boeing company has deployed extensive studies on this "funny" topics ... And now it is ridiculous to think that someone will have a gravitational weapon capable of, say, to produce earthquake .

And what about science? It's time to understand: science does not invent anything and does not open. People open and invent, open new phenomena, open new patterns, and it is already becoming science, using other people can make predictions, but only in the framework of those models and those conditions for which open models are correct, but go beyond these models Science itself is not able.

For example, the better the "scientific picture of the world", which is first, than that which they began to use later? Yes, only convenience, but what does it have to reality that and the other? The same! And if the carno substantiated the efficiency of the heat engine using the concept of heator plant, then this "picture of the world" was not worse than the one that these were knocking on the walls of the cylinder-molecule. What is one model better than another? Yes, nothing! Each model is true in a sense, in some other limits.

On the agenda, the question for science: explain how yoga sitting on the ass, plunge on half meter?!

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When cooling the superconductor in the external constant magnetic field, at the time of transition to the superconducting state, the magnetic field is completely outstrudy from its volume. This superconductor differs from the perfect conductor, in which the induction to zero falls magnetic field In the volume should be saved unchanged.

The absence of a magnetic field in the volume of the conductor allows you to conclude from the general laws of the magnetic field, which in it there is only a surface current. It is physically real and therefore takes some thin layer near the surface. The magnetic field of the current destroys the external magnetic field within the superconductor. In this regard, the superconductor behaves formally as an ideal diamagnet. However, it is not diamagnetic, since inside it magnetization is zero.

Maisner's effect cannot be explained only by infinite conductivity. For the first time, his nature was explained by the Brothers Fritz and Heinz Londons with the help of the London equation. They showed that in the superconductor, the field penetrates a fixed depth from the surface - the London depth of the magnetic field penetration λ (\\ displaystyle \\ lambda). For metals λ ~ 10 - 2 (\\ displaystyle \\ lambda \\ SIM 10 ^ (- 2)) μm.

Superconductors I and II kind

Clean substances in which the phenomenon of superconductivity is observed, are few. More often, superconductivity has alloys. In pure substances, there is a complete effect of the Maisner, and the alloys does not complete the magnetic field of the magnetic field from the volume (partial effect of the Maisner). Substances showing the full effect of Maisner are called superconductors of the first kind, and partial - second-sort superconductors. However, it is worth noting that in low magnetic fields, all types of superconductors possess the complete effect of the Maisner.

Superconductors of the second kind in the volume there are circular currents that create a magnetic field, which, however, fills not all the volume, and is distributed in it as separate yarrickos vieties. As for the resistance, it is zero, as in the superconductors of the first kind, although the movement of the vortices under the action of the current current creates an effective resistance in the form of dissipative losses for the movement of the magnetic flux within the superconductor, which is avoiding input into the structure of the superconductor defects - pinning centers, for which Vortices are "cling."

"Magomet Coffin"

Magomet Coffin is an experience that demonstrates the effect of Maisner in superconductors.

origin of name

According to legend, the coffin with the body of the Prophet Magomet hung in space without any support, so this experiment is called the "Magomet Coffin".

Setting experience

Superconductivity exists only at low temperatures (in the HTSC-ceramics - at temperatures below 150), so the pre-substance is cooled, for example, with liquid nitrogen. Next, the magnet is placed on the surface of a flat superconductor. Even in the fields,

For the first time, the phenomenon was observed in 1933 by German physicists by Maisner and Oxenneld. The basis of the Maisner effect is the phenomenon of the full displacement of the magnetic field from the material when switching to the superconducting state. The explanation of the effect is associated with a strictly zero value of electrical resistance of superconductors. The penetration of the magnetic field into the ordinary conductor is associated with a change in the magnetic flux, which, in turn, creates an induction EMF and the induced currents that prevent the change in the magnetic flux.

The magnetic field penetrates into the superconductor to the depth, displacing the magnetic field from the superconductable constant, called the London constant:

Fig. 3.17 Mason Effect Scheme.

The figure shows the magnetic field lines and their displacement from the superconductor located at temperatures below the critical one.

When switching temperature through a critical value, a magnetic field will change dramatically in the superconductor, which leads to the appearance of an emf pulse in the inductance coil.

Fig. 3.18 Sensor implements Maisner effect.

This phenomenon is used to measure ultra-plastic magnetic fields, to create cryotronov(Switching devices).

Fig. 3.19 The device and designation of cryotron.

Constructively, cryotron consists of two superconductors. Around the tantalum conductor, the coil of niobium is wound, according to which the control current flows. With an increase in the control current, the magnetic field strength increases, and the tantalum passes from the state of superconductivity into normal state. In this case, the conductivity of the tantalum conductor changes dramatically, and the operating current in the chain almost disappears. Based on cryotrons, create, for example, managed valves.

Magnet levitizes over a superconductor cooled with liquid nitrogen

Maisner effect - Full molding of the magnetic field from the material when switching to a superconducting state (if the field induction does not exceed the critical value). For the first time, the phenomenon was observed in 1933 by German physicists by Maisner and Oxenneld.

Superconductivity - the property of some materials to have a strictly zero electrical resistance when the temperature is reached below a certain value (the electrical resistance does not become close to zero, but disappears completely). There are several dozen clean elements, alloys and ceramics moving to a superconducting state. Currentness - not only just no resistance, it is also a certain reaction to an external magnetic field. The effect of the Maisner is that a constant not too strong magnetic field is pushed out of the superconducting sample. In the thickness of the superconductor, the magnetic field is weakened to zero, superconductivity and magnetism can be called as opposite properties.

Kent Hovind in his theory suggests that to a great flood, the planet Earth was surrounded by a large layer of water consisting of ice particles that were held in orbit, above the atmosphere, using the Mason Effect.

This aqueous shell served as protection against solar radiation and provided a uniform distribution of heat on the surface of the Earth.

Illustrating experience

A very spectacular experience demonstrating the presence of the Maisner effect is presented in the photo: a permanent magnet soars over a superconducting cup. For the first time, such an experience was carried out by the Soviet physicist V. K. Arkadyev in 1945.

Superconductivity exists only at low temperatures (a high-temperature superconductor ceramics exists at temperatures of about 150 K), so the substance is cooled, for example, with liquid nitrogen. Next, the magnet is placed on the surface of a flat superconductor. Even in the fields of 0.001 TL noticeably displacement of the magnet up at the distance of the order of the centimeter. With an increase in the field, up to a critical magnet rises higher above.

Explanation

One of the properties of second-type superconductors is the pushing of a magnetic field from the superconducting phase area. Stripping from a fixed superconductor, the magnet pops up and continues to steer until the external conditions contain a superconductor from the superconducting phase. As a result of this effect, the magnet approaching the superconductor will "see" the magnet of the opposite polarity of exactly the same size as the levitation causes.

Even more important property of the superconductor than zero electrical resistance is the so-called Maisner effect, consisting in the displacement of a constant magnetic field from the superconductor. From this experimental observation, it is concluded that the existence of the unlucky currents within the superconductor, which create an inner magnetic field, oppositely directed by an external, applied magnetic field and compensating for it.

A sufficiently strong magnetic half recovery of this temperature destroys the superconducting state of the substance. The magnetic field with the voltage H c, which at a given temperature causes the transition of a substance from the superconducting state into normal, is called a critical field. With a decrease in the temperature of the superconductor, the value of H c increases. The dependence of the magnitude of the critical field on temperature with good accuracy is described by the expression

where is the critical field at zero temperature. Superconductivity disappears when the electrical current is passing through the superconductor, greater than the critical, since it creates a magnetic field, greater critical.

The destruction of the superconducting state under the action of the magnetic field differs in superconductors I and II of the genus. For the superconductors of the genus II, there are 2 values \u200b\u200bof the critical fields: H C1 in which the magnetic field penetrates into the superconductor in the form of an apricot and n c2 vortex - at which the disappearance of superconductivity occurs.

Isotopic effect

The isotopic effect in superconductors lies in the fact that the temperatures of T C are inversely proportional to square roots from the atomic masses of the isotopes of the same superconducting element. As a result, monoisotropic drugs are somewhat different at critical temperatures from the natural mixture and from each other.

Moment of London

The rotating superconductor generates a magnetic field, precisely aligned with the axis of rotation, the arising magnetic moment called the name "Moment of London". It was used, in particular, in the scientific satellite "Gravity Probe B", where the magnetic fields of four superconducting gyroscopes were measured to determine their axis of rotation. Since almost perfectly smooth spheres served as gyroscope rotors, the use of the moment of London was one of the few ways to determine their axis of rotation.

Application of superconductivity

Significant progress has been achieved in obtaining high-temperature superconductivity. On the basis of metal ceramics, for example, the composition of YBA 2 Cu 3 O x, substances are obtained for which the temperature t with the transition to the superconducting state exceeds 77 K (liquefaction temperature). Unfortunately, almost all high-temperature superconductors are not technological (fragile, do not have the stability of properties, etc.), as a result of which the technique still uses mainly superconductors based on niobium alloys.

Superconductance phenomenon is used to obtain strong magnetic fields (for example, in cycloturons), since when the superconductor of strong currents, creating strong magnetic fields, there are no thermal losses. However, due to the fact that the magnetic field destroys the state of superconductivity, t. N. N. To obtain strong magnetic fields. Superconductors of genus, in which the coexistence of superconductivity and magnetic field is possible. In such superconductors, the magnetic field causes the appearance of thin yarns of a normal metal, penetrating the sample, each of which carries a quantum of magnetic flux (Vorki Abrikosov). The substance between the thread remains superconducting. Since in the superconductor II of the genus there is no complete effect of the Maisner, superconductivity exists to much greater values \u200b\u200bof the magnetic field H C 2. The technique applies mainly the following superconductors:

There are photon uniform detectors. In some, the presence of a critical current is used, and the effect of Josephson, Andreevsky reflection, etc. So, there are superconducting single-photon detectors (SSPD) to register single photons of IR ranges that have a number of advantages over the detectors of a similar range (FEUDD) using other ways to register .

The comparative characteristics of the most common IR range detectors based on the properties of superconductivity (first four), as well as superconducting detectors (last three):

View of the detector	Maximum account speed, C −1	Quantum efficiency,%	, C. −1	NEP W.
Ingaas PFD5W1KSF APS (Fujitsu)
R5509-43 PMT (Hamamatsu)
Si APD SPCM-AQR-16 (EG \\ & G)
MEPSICRON-II (Quantar)

			less than 1 · 10 -3	less than 1 · 10 -19
			less than 1 · 10 -3

Vortices in second-type superconductors can be used as memory cells. Such an application has already found some magnetic solitons. There are also more complex two and three-dimensional magnetic solitons resembling vortices in liquids, only the role of current lines in them play lines for which elementary magnets (domains) are built.

Lack of heating losses When passing a direct current through a superconductor makes attractive use of superconducting cables for electricity delivery, since one thin underground cable is capable of transmitting the power that the traditional method requires the creation of a power line circuit with several cables a lot of greater thickness. Problems that prevent widespread use is the cost of cables and maintenance - through superconducting lines it is necessary to constantly pump liquid nitrogen. The first commercial superconducting power line was commissioned by American SuperConductor Naong-Isalendevnyu-Yorkev late June 2008. South Korea's power systems are going to create over 2015 superconducting power lines with a total length of 3000 km.

Important application Find miniature superconducting device-rings - squid, the action of which is based on the connection of changes in magnetic flux and voltage. They are part of the ultra-sensitive magnetometers, the Measuring Madrunning Field of the Earth, as well as used in medicine to obtain the magnetograms of various organs.

Superconductors are also used in Maglava.

The phenomenon of the dependence of the transition temperature to the superconducting state from the magnitude of the magnetic field is used in cryotron-controlled resistances.

Zero resistance is not the only feature of superconductivity. One of the main differences with superconductors from ideal conductors is the Mason Effect, Outdoor Walter Maisner and Robert Oxenfeld in 1933.

The Maisner effect consists in the "pushing" of the superconductor of the magnetic field from the part of the space. This is caused by the existence of unlucky currents within the superconductor, which create an inner magnetic field oppositely directed by the applied external magnetic field and compensating for it.

When cooled a superconductor located in an external constant magnetic field, at the time of transition to the superconducting state, the magnetic field is completely outstrudy from its volume. This superconductor differs from the perfect conductor, in which the induction of the magnetic field in volume should be maintained unchanged to zero.

For the first time, Maisner's effect was explained by the Brothers Fritz and Heinz London. They showed that in the superconductor magnetic field penetrates a fixed depth from the surface - the London depth of the magnetic field penetration λ . For metals l ~ 10-μm.

Clean substances in which the phenomenon of superconductivity is observed, are few. More often, superconductivity has alloys. In pure substances, there is a complete effect of the Maisner, and the alloys does not complete the magnetic field of the magnetic field from the volume (partial effect of the Maisner). Substances showing the full effect of Maisner are called superconductors of the first kind and partial - superconductors of the second kind .

Superconductors of the second kind in the volume there are circular currents that create a magnetic field, which, however, fills not the whole volume, but is distributed in it as individual threads. As for the resistance, it is zero, as in the superconductors of the first kind.

The transition of the substance into the superconducting state is accompanied by a change in its thermal properties. However, this change depends on the genus of the superconductors under consideration. So, for superconductors ι kind in the absence of a magnetic field at a transition temperature T S. The warmth of the transition (absorption or selection) appeals to zero, and therefore it tolerates the heat capacity, which is characteristic of the phase transition ιι of the genus. When the transition from the superconducting state into normal is carried out by changing the applied magnetic field, the heat should be absorbed (for example, if the sample is thermally insulated, then its temperature decreases). And this corresponds to the phase transition ι of the genus. For superconductors ιι kind, the transition from the superconducting to normal state under any conditions will be a phase transition of ιι genus.

The phenomenon of the magnetic field pushing can be observed in the experiment, which was called "Magomet Coffin". If the magnet is put on the surface of a flat superconductor, then you can observe levitation - the magnet will hang at some distance from the surface without touching it. Even in the fields with an induction of about 0.001tl noticeably displacement of the magnet up at the distance of the order of the centimeter. This is explained by the fact that the magnetic field is pushed out of the superconductor, so the magnet approaching the superconductor will "see" the magnet of the same polarity and exactly the same size, which will cause levitation.

The name of this experiment is "Magomet Coffin" - due to the fact that according to legend, the coffin with the body of the Prophet Magomet hung in space without any support.

The first theoretical explanation of superconductivity was given in 1935 by Fritz and Heinz London. A more general theory was built in 1950 by LD. Landau and VL. Ginzburg. She gained widespread and is known as the theory of Ginzburg - Landau. However, these theories had phenomenological character and did not disclose the detailed superconductivity mechanisms. For the first time, superconductivity on the microscopic level was explained in 1957 in the work of American physicists John Bardina, Leon Cooper and John Sriffera. The central element of their theory, called the BCS theory, are the so-called Cooper pairs of electrons.

The chaotic movement of the conductory atoms prevents the passage of electric current. The conductor resistance decreases with a decrease in temperature. With a further decrease in the temperature of the conductor, the resistance and phenomenon of superconductivity is observed.

At some temperature (close 0 OK), the resistance of the conductor drops sharply to zero. This phenomenon is called superconductivity. However, in superconductors, another phenomenon is also observed - the Maisner effect. Explorers in the superconducting state detect unusual property. From the volume of the superconductor completely displaces the magnetic field.

Displacing a magnetic field superconductor.

The conductor in the superconducting state, unlike the perfect conductor, behaves like a diamagnet. The outer magnetic field is displaced from the volume of the superconductor. Then if you place a magnet over a superconductor, a magnet freezes in the air.

The occurrence of this effect is due to the fact that when making a superconductor to the magnetic field, there are vortex induction currents in it, the magnetic field of which will fully compensate for the external field (as in any diamagnet). But the induced magnetic field itself also creates vortex currents, the direction of which is opposite to induction currents in the direction and is equal in magnitude. As a result, there is no magnetic field and current in the volume of the superconductor. The volume of the superconductor is shielded by a thin near-surface layer - the skin-layer - on the thickness of which (about 10-7-10-8 m) penetrates the magnetic field and in which it compensation occurs.

but - A normal conductor with a different resistance from zero at any temperature (1) is entered into a magnetic field. In accordance with the law of electromagnetic induction, currents arise that resist the penetration of the magnetic field into the metal (2). However, if the resistance is different from zero, they quickly fade away. The magnetic field permeates the sample of a normal metal and almost uniformly (3);

b. - from a normal state at temperatures above T. C There are two ways: the first: with a decrease in temperature, the sample goes into a superconducting state, then you can apply a magnetic field that is energized from the sample. The second: first impose a magnetic field that penetrates into the sample, and then lower the temperature, then the field will push the field. Turning off the magnetic field gives the same picture;

in - If there was no effect of the Maisner, the conductor without resistance would lead himself differently. When moving to a state without resistance in a magnetic field, it would maintain a magnetic field and retain it even when removing an external magnetic field. Mojabling such a magnet could only be increasing the temperature. This behavior, however, is not observed on experience

In 1933, the German physicist Walter Fritz Maisner together with his colleague Robert Oxenfeld opened the effect, which was subsequently called him name. The Maisner effect is that when switching to a superconducting state, a complete outpacing of the magnetic field from the conductor volume is observed. It can be clearly obstaciously to observe with the help of the experience given by the name "Magomet Coffin" (according to the legend, the coffin of the Muslim prophet Magomet hung in the air without physical support). In this article we will tell about the effect of Maisner and its future and true practical application.

In 1911, Heik Challing-Onane made an important discovery - superconductivity. He proved that if you cool some substances to a temperature of 20 k, then they do not resist electrical current. The low temperature "soothes" random fluctuations in atoms, and electricity does not meet resistance.

After this discovery began a real race for finding such substances that will not have resistance without cooling, for example, at ordinary room temperature. Such a superconductor will be able to transmit electricity to gigantic distances. The fact is that the usual power lines lose a significant amount of electric current, just because of the resistance. In the meantime, physicists put their experiments with the help of cooling superconductors. And one of the most popular experiments is the demonstration of the Mason Effect. In the network you can find a lot of rollers showing this effect. We posted one that best demonstrates it.

To demonstrate the experience of levitation of the magnet over the superconductor, you need to take high-temperature superconducting ceramics and a magnet. Ceramics is cooled by nitrogen to superconductivity. The current is connected to it and the magnet is placed on top. In the fields 0.001 toll, the magnet shifts up and levitates over a superconductor.

The effect is explained by the fact that in the transition of a substance into superconductivity, the magnetic field is pushed out of its volume.

How can I apply the Maisner effect in practice? Probably, each reader of this site saw many fantastic films in which cars batted over expensive. If it is possible to invent a substance that turns into a superconductor at a temperature, let's say not lower than +30, then it will not be fantastic.

And what about ultra-speed trains, which also hover over the railway. Yes, they exist now. But unlike the Maisner effect, there are other laws of physics: repulsion of the unipolar sides of the magnets. Unfortunately, the high cost of magnets does not allow you to extend this technology. With the invention of the superconductor, which you do not need to cool, flying machines will become a reality.

In the meantime, the effect of Maisner took on its weapons of magicians. One of these ideas we were excavated for you on the network. Its tricks shows the exos troupe. No magic is only physics.

Mysterious quantum phenomena still surprise researchers with their unimaginable behavior. Earlier, we talked about, today we consider another quantum-mechanical phenomenon - superconductivity.

What is superconductivity? Superconductivity is a quantum phenomenon of the flow of electric current in a solid body without loss, that is, with a strictly zero electrical resistance of the body.

With the introduction into physics of such a concept as "absolute zero", scientists have become increasingly investigating the properties of substances at low temperatures when the movement of molecules is practically absent. To achieve low temperatures, such a process is required as "gas liquefaction". When evaporated, such gas selects energy from the body, which is immersed in this gas, since it requires energy for the separation of molecules. Such processes occur in household refrigerators, where the liquefied gas Freon evaporates in the freezer.

At the end of the XIX - early XX century, such liquefied gases were already obtained as oxygen, nitrogen, hydrogen. For a long time, it was not amenable to liquefying helium, while it was expected that it would help to achieve the minimum temperature.

Success in the liquefaction of helium was achieved by the Dutch physicist Heik Kamelning-Onnence in 1908, which worked at Leiden University (Netherlands). Liquefied helium allowed to achieve a record low temperature - about 4 K. Having obtained liquid helium, the scientist began to study the properties different materials under helium temperatures.

History opening

One of the questions that was interested in the chamber-onnes was to study the resistance of metals at ultra-low temperatures. It was known that with increasing temperature, electrical resistance also grows. Therefore, it can be expected that a reverse effect will be observed with a decrease in temperature.

Experimenting with mercury in 1911, the scientist brought it to freezing and continued to lower the temperature. Upon reaching 4.2 to the device stopped fixing the resistance. Onnes replaced the device in the research unit, since their malfunctions were afraid, but the devices were invariably showed zero resistance, despite the fact that another 4 K. remained to absolute zero

After the opening of superconductivity of mercury arose a large number of questions. Among them: "Are the superconductivity of other substances, in addition to mercury?" Or "Resistance is reduced to zero, or it is so little that the devices that exist cannot measure it.

Onnes suggested an original study with an indirect measurement, to what level resistance decreases. An electrical current is excited in the semiconductor circuit, which was measured by deviation of the magnetic arrow, did not slide for several years. According to the results of this experiment, obtained by calculations, the specific electrical resistance of the superconductor was equal to 10-25 OM.M. Compared to the electrical electrical resistance of copper (1.5010-8 OM.M.), this value is less than 7 orders of magnitude, which makes it almost zero.

Maisner effect

In addition to superconductivity, superconductors possess one more distinctive feature, namely, the effect of Maisner. This is the phenomenon of rapid attenuation of the magnetic field in the superconductor. The superconductor is a diamagnetic, that is, macroscopic currents are induced in the magnetic field in the superconductor, which create their own magnetic field, which completely compensates for the external.

The effect of Maisner disappears in strong magnetic fields. Depending on the type of superconductor (about this below), the superconducting state is either completely (superconductors of the i-th genus), or the superconductor is segmented with normal and superconductible areas (II). It is this effect that is capable of explaining the levitation of the superconductor over a strong magnet, or a magnet over the superconductor.

Theoretical explanation of the effect of superconductivity

Phenomenological approach. Although Challing-Onane is the primary superconductance, the first theory of superconductivity was first proposed in 1935 by German physicists and brothers Fritz and Geanez Londons. Scientists sought to mathematically write such properties of the superconductor as superconductivity and the effect of the Maisner, not adhering into microscopic causes of superconductivity, phenomenologically. The derived equations allowed to explain the effect of Maisner so that the external magnetic field could penetrate into the superconductor only on a certain depth, depending on the so-called London penetration depth. To explain superconductivity, it was assumed that the current carriers in the superconductor, as in the metal, are electrons. At the same time, zero resistance means that the electron does not experience collisions during his movement. Since this applies to all conductivity electrons, there is a current of electrons without resistance.

It is obvious that this theory does not explain the nature of this phenomenon itself, but only describes it and allows you to predict his behavior in some cases. The deeper, but also, the phenomenological theory was proposed in the 1950s by Soviet physicists of theoretics left Landau and Vitaly Gisburg.

BCH theory. The first qualitative explanation for the phenomenon of superconductivity was proposed within the framework of the so-called theory of BKS, built by American physicists John Bardin, Leon Cooper and John Srineffer. This theory comes out of the assumption that an attraction may occur between electrons under certain conditions. Attraction, which is due to various excitations, first of all - the oscillations of the crystal lattice, can create "Cooper's pairs" - the associated states of two electrons in the crystal. Such a pair can move in a crystal without dispelled on the oscillations of the crystal lattice or impurities. In substances with a temperature, far from zero, there is enough energy to "break" such a pair of electrons, while at low temperatures the system does not have enough energy. As a result, the flow of associated electrons - Cooper couples, which practically do not interact with the substance are arising. In 1972, D. Bardin, L. Cooper and D. Schrifer received the Nobel Prize in Physics.

Later, the Soviet Physico theorist Nikolai Bogolyubov improved the theory of BKSH. In their works, the scientist described in detail the conditions under which Cooper pairs can form (the energy is close to the Fermi energy, certain spins, etc.) as a result of quantum effects. Separately, electrons are particles with a half-spin (fermions), which are unable to form and switch to the superfluid state. When there is a cooper pair of electrons, it is a quasiparticle with a whole spin and is. Under certain conditions, bozones are capable of forming condensate Bose Einstein, that is, the substance whose particles occupy the same condition, which leads to superfluidity. Such superfluidity of electrons and explains the effect of freshness.

Superconductors in an alternating electric field

In addition to superconductivity and the effect of Maisner, superconductors have a number of other properties. It is worth noting the following - the zero resistance of superconductors is characteristic only at constant current. Variables electric field Makes the resistance of the superconductor non-zero and it grows, with an increase in the field frequency.

Also, as a two-dimensional model, the superfluid material on the region of superfluidity and the region of the conventional substance is separated, and the electron flow to superconducting and ordinary. Constantly the field would speed up superconducting electrons to infinity (given their zero resistance), which is impossible, therefore it turns to zero when entering the superconductor. Since the constant electric field does not act on superconductors, then conventional electrons are not exposed to its effects (it is simply energged out), which means the movement is represented only by superconducting electrons.

In the case of an alternating electric field, the process of accelerating electrons followed by a slowdown, which is physically possible. In this case, there is also a current of ordinary electrons, which have the resistance property. The higher the frequency of this field, the greater the effects associated with ordinary electrons appear.

Moment of London

Another interesting property of the superconductor is the moment of London. The essence of the phenomenon is that the rotating superconductor creates a magnetic field that is aligned precisely along the axis of rotation of the conductor.

Further study of this phenomenon led to the opening of the gravity of the magnetic moment of London. In 2006, researchers Martin Tajmar from the ARC SEIBERSDORF Research Institute, Austria, and Klovis de Matos from the European Space Agency (ESA) found that the acceleration of the reservoir also generates a gravitational field. However, such a gravitational field is weaker than the Earth about 100 million times.

Classification of superconductors

There are several classifications of superconductors, which are based on criteria:

The reaction to the magnetic field. This property divides superconductors into two categories. The superconductors of the i-th genus have some one critical value of the magnetic field, exceeding which they lose superconductivity. II - have two limit values \u200b\u200bof the magnetic field. When using a magnetic field, limited by these values, to superconductors of this category, the field partially penetrates the inside, while maintaining superconductivity.
Critical temperature. There are low-temperature and high-temperature superconductors. The first possesses the property of superconductivity at temperatures below -196 ° C or 77 K. High-temperature superconductors are sufficient temperatures above the specified. Such separation takes place, since high-temperature superconductors can be used in practice as coolers.
Material. Here we allocate such varieties like: clean chemical element (such as mercury or lead), alloys, ceramics, organic or iron-based.
Theoretical description. As is known, any physical theory has a certain application. For this reason, for further use, it makes sense to divide superconductors on theories that are able to describe their nature.

Superconductance of graphene

Over the past few years, graphene has increased significantly. Recall that graphene is a layer of modified carbon, one atom thick. First of all, this contributed to the discovery of carbon nanotubes - a specific superproof material, which is created by turning one or more of the graphene layers.

In 2018, a group of researchers from the Massachusetts Institute of Technology and Harvard University under the guidance of Professor Pablo Jarillo-Errroo, discovered that when rotating under a certain ("magically") angle, two graphene sheet completely devoid of electrical conductivity. When the researchers applied to the material voltage, adding a small number of electrodes to this graphene design, they found that at a certain level, the electrons escaped from the initial insulating state and flowed without resistance. The most important feature of this phenomenon is that the superconductivity of the specified graphene structure was obtained at room temperature. And although the explanation of this effect is still questionable, its potential in the field of energy supply is quite high.

Application of superconductors

Superconductors have not yet been widely used, but the development in this area is actively conducted. So thanks to the effect of Maisner, "soar" over the road on the magnetic cushion is possible - Maglev.

Based on superconductors, heavy duty turbogenerators are already created, which can be applied on power plants.

Cryotron is another use of superconductivity, which can be useful for technology and electronic devices. This is a device that can switch the state of the superconductor from the usual to the superconducting in a very short time (from 10⁻⁶ to 10⁻⁻⁻с). Cryotrons can be used in memorization and coding information systems. So for the first time they were used as storage devices in the computer. Also, cryotrons can help in the area of \u200b\u200bcryoelectronics, among the tasks of which - increase the sensitivity of the signal receivers and save the signal form as much as possible. Here to achieve goals contribute low temperatures and superconductivity effect.

Also, due to the absence of resistance in superconductors, cables from such a substance would deliver electricity without loss of heating, which would significantly increase the efficiency of power supply. Today, such cables require cooling through liquid nitrogen, which increases the price of their operation. However, research in this area is conducted, and the first power transmission on the basis of superconductors was maintained in New York 2008 by American SuperConductor. In 2015, South Korea announced the intention to create several thousand kilometers of superconducting power lines. If you add to this the recent opening of graphene superconductivity at room temperature, then global changes in the field of power supply should be expected in the near future.

In addition to these applications, superconductivity is used in measuring equipment, ranging from photon detectors and ending with a measurement of geodetic precession through superconducting gyroscopes on the Space Actuator "Gravity Probe B". This measurement confirmed the prediction of Einstein on the presence of such a precession for the reasons set forth in the general theory of relativity. Without deep into the measurement mechanism, it should be noted that the data on the geodesic precession of the Earth makes it possible to accurately calibrate the artificial satellites of the Earth.

Summing up the above, it suggests the conclusion about the prospects for the effect of superconductivity in a variety of areas, and the large potential of superconductors, primarily in the spheres of power supply and electrical engineering. We expect many discoveries in the near future in this area.

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