Railgun - the weapon of the future. American rail guns: fantastic weapons for ships of the future Electromagnetic rail gun

Science does not stand still; in the race for world domination, people are inventing more and more advanced weapons that threaten stability globe and keeping enemies and ill-wishers in check.

American scientists are once again going to surprise the whole world by presenting a new weapon, which has already been dubbed “Weapons of the Twenty-First Century.” Under this scary and promising name lies an industrial prototype of an electromagnetic gun. The world's most powerful electromagnetic gun is called "Railgun" and plans to begin a completely new chapter of world weaponry.

RailGun, being a pulsed electrode mass accelerator, allows you to transform electrical energy to kinetic. The name of the device was born because of the appearance of the system. Strictly speaking, what are called “rails” are actually parallel electrodes connected to a direct current source. The projectile is placed between them, and an electrical circuit is closed to impart acceleration. The main goal of developing such technology is to equip the US Navy with similar weapons. It is assumed that the shot range will reach four hundred kilometers.

The rail gun uses electromagnetic force (Laurenz force) to accelerate the projectile, which is part of the chain initially.

The advantages of using a railgun are undeniable:

• High destructive power of the shot;
• Impressive firing range (from 150 to 350 km);
• The safety of this type of weapon due to the absence of gunpowder/explosive fuel;
• The reduced weight will allow the equipment to be equipped with a larger number of charges;
• The projectile speed can reach nine thousand kilometers per hour.

The industrial prototype will be more durable. However, despite seeming promising, the project has many limitations that prevent the rapid equipping of US warships:

• A clear, sharp impulse is needed that will accelerate and push the projectile before it scatters or evaporates;
• A huge amount of energy with which the pulse gun will be powered;
• Adverse effects of moisture and salt, exposing the system to corrosion;
• System stabilization;
• Complete unmasking launcher, which occurs after the first shot;

Large sums spent on testing and improving a laboratory sample with an unclear time frame for full-scale implementation. In order to solve the problem of equipping RailGun with energy, additional research is being carried out in parallel. The projectile must have a minimum mass, the material for making the projectile and the rail must have high conductivity.

Work on the railgun continues

In parallel with work on an energy source that allows multiple shots without complete replacement, scientists are working on improving the system: its compact size, the materials from which parts of the gun are made, its safety.

If the results of the test of the gun are successful, then this will truly be a real breakthrough in the organization of military operations on the water. The Americans, having achieved success in the implementation of the railgun, will be able to dominate the military sphere without any problems. High-precision destruction of targets at long distances will become possible, and the enormous speed achieved by the projectile will contribute to its enormous destructive effect. An important fact is that the cost of a railgun projectile is several times lower than the cost of other anti-ship projectiles, and the system can be maintained by just one person - the gunner.

Work on improving the railgun is being carried out in the United States with varying degrees of success. In 2011, there was a serious threat of closure of the project as unpromising and “futuristic”. However, Barack Obama defended the “weapons of the 21st century” by signing a corresponding decree. Currently, a number of people are working on the project large companies, such as General Atomics and BAE Systems), which envision equipping warships with railguns within ten years. To implement this program, it is necessary to refine the energy source that powers the RailGun. It should work like a battery, storing enough a large number of energy, and half measures will not solve the problem: what is the point of expensive weapons capable of firing several single shots? In addition, the stated rate of fire of the gun from 6 to 10 rounds per minute is only a theory, and even then insufficient.

Work to increase the rate of fire involves the search for more wear-resistant materials: the guides in the gun have to be changed after every second shot. Working to increase speed leads to the destruction of projectiles in flight, and this also becomes a serious obstacle to large-scale implementation of the railgun. To this list we can add the need for a high-precision guidance and sighting system, and it becomes obvious that the American plans can safely be called overly optimistic.

History of the creation of RailGun

But the first tests of such weapons were carried out by the Germans during the Second World War. The weapon was tested in a railway tunnel in Bavaria, and the results raised hopes of creating a formidable electromagnetic weapon. The prototype of the gun accelerated a ten-gram aluminum cylinder to a speed of over 4 thousand km/h, but was captured by the Americans, who appreciated the idea.

Thoughts about creating such weapons came to the minds of Canadian, Australian, and English scientists. In the years cold war“Similar work was carried out by Soviet scientists. These developments were strictly secret, but rumors about achievements and planned weapons Soviet army weapons based on a similar principle were carried out until the collapse of the state. Russia did not have enough economic opportunities to continue work in this direction, and the project was curtailed for a long time. Today, work on the creation of electromagnetic weapons is being carried out in our country, and in parallel there are debates about the advisability of introducing such weapons.

A power that manages to implement the idea of ​​arming its army with pulse weapons will be able to dictate its terms to the world, but for now we're talking about only about theoretical dominance.

Greetings from Quake 3 Arena
Railgun, or in common parlance “rail”, is a pulsed electrode mass accelerator, the principle of operation of which is explained using the Lorentz force, which converts electrical energy into kinetic energy. It is a promising weapon that has a number of advantages over the classical design based on a chemical explosion. AND combat tests this beauty is just around the corner.

Operating principle and limitations

A rail gun uses an electromagnetic force called the Lorentz force to accelerate an electrically conductive projectile that is initially part of a circuit. Sometimes movable reinforcement is used to connect the rails. A current I passing through the rails excites a magnetic field B between them, perpendicular to the current passing through the projectile and the adjacent rail. As a result, mutual repulsion of the rails occurs and the projectile accelerates under the influence of force F.

One of the problems with the railgun is that to make its projectiles, a material with the highest possible conductivity is needed, because for creating driving force A very powerful instantaneous discharge of current is released along the rails. If the projectile material is not sufficiently conductive, it may be vaporized in the railgun by the current before leaving the gun.

The second limiter is the power supply. In the near future, the US Navy plans to test a railgun on a ship base (only a ship today can withstand a shot from this weapon). A salvo from a modern railgun requires an impulse of 25 (!) megawatts. One of the US Navy ships, which was designed specifically to be equipped with a railgun, is equipped with power plants of 78 megawatts, and the most common value of el. The installation power on the ship is 9 megawatts. For one shot of a railgun, almost 30% of the power of the special installation is required. fleet ship. You shouldn’t even think about using this type of weapon on ordinary ships.

Video from the US Navy experimental installation:

Question to the audience: where did the fiery flash at the exit come from? :)

Sometimes, to give the railgun projectile the highest initial speed, at which the shot will be more effective, a chemical explosion is produced (detonation of gunpowder, for example). To exaggerate, the railgun can be used as an “accelerating attachment” for guns, increasing the exit speed of the projectile. But I wouldn't risk running that kind of current through explosives.

Non-conductive projectile

There is another type of railgun that uses a non-conductive projectile. In the described case, the rails are closed not by the projectile itself, which leads to the formation of the Lorentz force, but separately, behind the projectile, forming an arc discharge. The latter leads to the evaporation of the projectile and the formation of a jet stream, which, moving the projectile along the rails, accelerates it.

Not to be confused with the Gauss gun

The Gauss gun and the railgun are often confused. The reason for this is the similar nature of the operation of these devices, but they use different approaches and electro-physical laws to accelerate the projectile. The railgun uses the Lorentz force or jet stream, and the Gauss gun uses electromagnetic fields. A ferromagnetic projectile is accelerated along a dielectric tube through a series of solenoids, which, when turned on, form a magnetic field that “pushes” the ferromagnetic projectile forward.

A Gauss gun has an efficiency significantly lower than a railgun, so the military does not consider this principle for creating weapons.

So why is such a complex railgun so tasty for the military?

Everything is so banal - money. “Rail” is capable of firing at a distance of up to 180 km today, and in the future it is planned to reach targets of up to 400 km. It is possible to fire at such distances only with the help of missiles, each of which costs millions of dollars, plus they know how to fight them. The railgun can already fire projectiles weighing 2-3 kg, which at speeds of up to 2000-2500 m/s leads to colossal destruction. The projectile itself costs about $20-25 thousand, compared to the cost of missiles - for free, and transportation and operation of such ammunition is a pleasure: the ammunition will not detonate, no problems with loading, no emergency situations due to the human factor (unless, of course, someone Someday he won’t drop it on his foot).

Scientists only have to resolve the issue with the power source, because... building ships specifically for the “rail” is very expensive (a power plant of 70 megawatts is the energy consumption of a small city). As soon as the power supply issue is resolved, we will be able to see railguns in service. And it’s not clear how to deal with a three-kilogram blank flying at a speed of Mach 7 and capable of sinking a ship.

Despite the disastrous reforms in our Armed Forces, the army's scientific and technical intelligence does not stand still; the development of new types of weapons continues that can radically change not only the nature of modern combat, but also the balance of forces in the system of military confrontation on the world stage. We will talk about some of them in materials under the heading "Russia's new weapon."

Shatura miracle

Recently in the laboratory of the Shatura branch of the United Institute high temperatures Russian Academy Sciences tested a unique device - Artsimovich railgun, which represents electromagnetic gun, which still fires very small projectiles - weighing up to three grams. However, the destructive abilities of such a “pea” are amazing. Suffice it to say that the steel plate placed in its path simply evaporated, turning into plasma. It's all about the gigantic speed imparted to the projectile by an electromagnetic accelerator used instead of traditional gunpowder.

After testing Director of the Shatura branch of the Joint Institute for High Temperatures of the Russian Academy of Sciences Alexey Shurupov told reporters present:

— In our laboratory tests maximum speed reached 6.25 kilometers per second with a projectile mass of several grams (about three grams). It's very close to first escape velocity.

What kind of gun is this, and what opportunities does it promise?

Gauss principle

To begin with, it should be noted that the search alternatives to using gunpowder as a working substance for accelerating a projectile in a gun barrel began at the beginning of the last century. As is known, powder gases have a fairly large molecular weight and, as a consequence, a relatively low expansion rate. The maximum speed achieved by a projectile in traditional artillery systems, is limited to a value of the order of 2−2.5 km/s. This is not so much if the task is to pierce the armor of an enemy tank or ship with one shot.

It is believed that they were the first to put forward the idea of ​​​​an electromagnetic gun French engineers Fachon and Villeplee back in 1916. Based on the principle of induction by Karl Gauss, they used a chain of solenoid coils as a barrel, to which current was sequentially supplied. Their current model of induction gun accelerated a 50 gram projectile to a speed of 200 meters per second. Compared to powder artillery installations the result, of course, turned out to be quite modest, but it showed the fundamental possibility of creating a weapon in which the projectile accelerates without the help of powder gases. In fact, even a year before Fachon and Villeple Russian engineers Podolsky and Yampolsky developed a project for a 50-meter “magnetic-fugal” gun operating on a similar principle. However, they were unable to obtain funding to bring their idea to life. However, the French did not go further than the “Gauss gun” model, since the developments seemed too fantastic for that time. In addition, this new product, as already noted, did not provide any advantages regarding gunpowder.

— Systematic scientific works the creation of fundamentally new electrodynamic mass accelerators (EDMA) began in the world in the 50s of the 20th century,” he told a “SP” correspondent expert of the Russian Arms information center, reserve colonel Alexander Kovler.— One of the founders of domestic developments in this area was the outstanding Soviet scientist, plasma researcher L.A. Artsimovich, who introduced the concept of “railgun” into Russian terminology (in English-language literature the term “railgun” is adopted) to designate one of the varieties of EDUM. The idea of ​​a railgun was a breakthrough in the development of electromagnetic accelerators. It is a system consisting of a source of electricity, switching equipment and electrodes in the form of parallel electrically conductive rails 1 to 5 meters long, located in the trunk at a short distance from each other (about 1 cm). Electric current from the energy source is supplied to one rail and returned through a fuse-link located behind the accelerated body and closing the electrical circuit to the second rail. When high voltage is applied to the rails, the insert instantly burns out, turning into a cloud of plasma (it is called a “plasma piston” or “plasma armature”). The current flowing in the rails and piston creates a strong magnetic field between the rails. The interaction of the magnetic flux with the current flowing through the plasma generates an electromagnetic Lorentz force, which pushes the accelerated body along the rails.

Railguns make it possible to accelerate small bodies (up to 100 g) to speeds of 6−10 km/sec. Actually, you can do without a projectile at all and accelerate the plasma piston on its own. In this case, the plasma escapes from the accelerator at a truly fantastic speed - up to 50 km/sec.

What will it give?

During the Cold War, work on the creation of electromagnetic guns was actively carried out in both the USSR and the USA. They are still strictly classified. It is only known that by the mid-80s of the last century, both sides came very close to the possibility of placing a railgun gun with an autonomous power source on a mobile carrier - a tracked or wheeled chassis. There is also information that an individual weapon on this principle.

“The overall length of the rifles was small, but those who saw such a weapon for the first time were struck by the massiveness of the butt. But this is where the main mechanisms were located; There, behind the fire control handle, a very thick magazine was docked. It had such parameters not due to the countless cartridges. It just contained an additional, and quite powerful, battery. The rifle was a plasma rifle; it could not fire without electricity. Due to the caseless mechanics, it had a rate of fire inaccessible to other types of machine guns. And due to the acceleration of the bullets by plasma, they received a solid acceleration, definitely unattainable with powder devices... And only after the third or fourth silent and invisible volley did the understanding of what had happened come... someone screamed, struck by a bullet that first pierced the comrade in front, or even two. It’s a terrible thing—plasma overclocking!” - this is how the science fiction writer, “singer of high weapons technology” describes the use of electromagnetic weapons in the near future. Fedor Berezin in his novel Red Dawn.

To this we can add that such weapons can easily shoot down military satellites and missiles, and when placed on a tank, they can combat vehicle invulnerable. In addition, there will be practically no protection from it. Projectile with escape velocity will break through anything. Military expert Pavel Felgenhauer adds: “It will be possible to sharply reduce the caliber by at least half. This means more ammunition, less weight. There will be no artillery gunpowder on board, and this is the protection of the tank itself, it will be less vulnerable. There will be nothing to explode.”

Recently, information was leaked to the press that on December 10, 2010, the US Navy conducted a railgun test, which was considered successful. The weapon was tested at a power of 33 megajoules. According to calculations by the US Navy, this power allows you to fire a metal projectile at a distance of up to 203.7 kilometers, and at the end point the speed of the blank is about 5.6 thousand kilometers per hour. It is expected that by 2020 guns with a muzzle energy of 64 MJ will be created. These guns should go into service with the DDG1000 Zumwalt series destroyers being built in the United States, whose modular design and electric transmission were designed with an eye to promising EM guns.

With the US withdrawal from the ABM Treaty, work on placing electromagnetic guns in orbit also resumed. In this area, the developments of General Electric, General Research, Aerojet, Alliant Techsystems and others under contracts with the US Air Force DARPA are known.

We are behind, but not hopelessly

Market reforms in Russia have sharply slowed down work on the creation of a railgun. But, despite the reduction in funding for military development of electromagnetic weapons, domestic science also does not stand still. Evidence of this is the systematic appearance of Russian surnames in the materials of the annual international conference on Electromagnetic Acceleration EML Technology Symposium.

The tests in Shatura also indicate our progress in this direction. The comparative ratio of the capabilities of Russia and the United States in this area can be judged by specific test indicators. The Americans accelerated a three-kilogram projectile to 2.5 kilometers per second (which is close to a powder accelerator). Our projectile is a thousand times smaller (3 grams), but its speed is two and a half times higher (6.25 km/sec.)

Assessments of prospects also sound differently. “It is impossible to use such weapons on modern ships, both American and Russian. There simply isn't enough energy for him. It will be necessary to create a new generation of ships with an energy system that will provide both the ships’ engines and their weapons,” the Russian Navy’s Armament and Operations Directorate said in a statement published in the press. At the same time, American military magazines are already publishing mock-ups of the first ship that could receive the new weapon. The 21st century destroyer DDX should appear by 2020.

The high rate of railgun acceleration is due to the work of electromagnetic Lorentz forces in the gun mechanism. They arise and begin to act on the projectile when two parallel current-carrying (minus and plus sign) guide rails are short-circuited after a very powerful but very short current pulse is applied to them. As a current-closing element, a special fitting with a projectile built into it or the projectile itself, lying on the rails and closing them, is used. Lorentz forces are directed to push the projectile out of the cannon, and it flies out of the barrel at hypersonic speed. The acceleration of the projectile is also facilitated by the pressure of the plasma, which is formed behind the projectile from the action of a powerful arc discharge. Plasma at a speed of 50-100 km/h acts on the projectile as a kind of powerful jet stream.

Rails are expensive and vulnerable

In American experiments on the creation of electromagnetic weapons, as a rule, a special “shoe” shape is used as a reinforcement, in which the projectile is fixed. This design eliminates contact of the projectile with the rails. Guides made from silver-plated oxygen-free copper are highly susceptible to wear from friction and erosion. When using metal projectiles that perform a short circuit with their “body,” replacement of the rails is required after two or three shots.

The name “railgun” was invented in the 50s of the last century by Academician L. Artsimovich, a world expert in the field of thermonuclear fusion and high-temperature plasma physics. The plasma accelerator he invented was advanced to Nobel Prize, but the USSR removed the scientist’s candidacy from discussion due to the secrecy of the development.

The projectile itself is made of refractory tungsten. The high density of this metal allows even a heavy projectile to be made small, which solves the problem of placing ammunition in limited volumes of charging compartments or projectile magazines.

However, it is not only the rapid wear of the rails that prevents the railgun from turning into a superweapon; there are also other obstacles. First of all, these are power sources. The railgun requires a powerful power supply system in the form of unipolar generators, compulsors, and megawatt ionistor capacitors. These devices make it possible to generate a very powerful short electrical pulse transmitted to the rails. In laboratory conditions, one can put up with equipment units that are substantial in size and weight. In the navy, the factor of weight and volume is also not so significant: the ship has enough displacement to pack 130 tons of equipment in addition to the gun barrels themselves.

Railgun Blitzer production General Atomics (USA) is placed on two trailers - on one the gun itself, on the other - power plant. The development of EMF began in 2005 and was completed in 2011.

For ground-based military railguns, the problem seems more complex. If you placed the equipment on tank chassis, you would have to lead a 78-ton monster into battle. The solution was to distribute the installation between two car trailers (on one the gun itself, on the other - the “energy”), this option was implemented in the American Blitzer army gun. Another tractor-trailer was given to the control station. To power the ship's railguns (there will presumably be two of them on the high-tech destroyers of the Zumwalt project), a power reserve of the ship's installation (reserved only for railguns) of at least 35-45 MW is provided. The energy should be enough to accelerate the projectile to 2000-2500 m/s. Then, having received a muzzle energy of 64 MJ, he will be able to fly to a distance of up to 400 km and, having saved 20 MJ of energy, hit the target with a powerful kinetic blow. It has already been calculated that such a projectile weighing 18-20 kg hitting an aircraft carrier will produce the effect of a nuclear strike.

32 Golfs on target

Army guns have a shorter firing range - 80-160 km, which is why the “energy” for shots will require approximately half as much as the ship’s. For reference: a Golf passenger car has an energy of 1 MJ at a speed of 160 km/h. A railgun projectile weighing 10 kg with a muzzle energy of 32 MJ at a speed of 2500 m/s is capable of piercing three concrete walls or six 12 mm steel sheets, which is equivalent in effect to an explosion of 150 kg of TNT.

Serious obstacles to the widespread use of railguns are resonance phenomena in the rail system and the effect of pushing the rails away from the action of Lorentz forces, electromagnetic compatibility with the electronic systems of the gun, the need to cool the barrel and electronics units, etc.

During full-scale testing, the need was also identified for quickly reloading the gun to increase the rate of fire to at least 6-10 rounds per minute. This year, working in cooperation with the American military-industrial complex British company BAE Systems conducted firing tests at the US Navy training ground in Virginia. As the British say, in the next couple of years they expect to increase the rate of fire of their installation to 10 rounds per minute with a projectile weight of 16 kg, so this problem is gradually finding a solution.

Estimated projectile weight: 18 kg; Muzzle velocity: 2.5 km/s (Mach 7.5), twice that of conventional guns; Range: 400 km (for conventional naval guns - no more than 80 km); Projectile: destroys the target due to impact energy, does not contain explosives; Gun barrel length: 10 m

Indestructible electronics

The projectile has the most suitable conical elongated shape for hypersonics with a slightly blunt toe - this is a kind of pointed rod. The stabilizer in the tail allows you to keep the projectile on its flight path. The creation of such ammunition is another problematic area of ​​the railgun program.

The United States has been developing a unified hypersonic HVP projectile since 2012, and today it is already undergoing fire tests. It is unified because it will be used not only in railguns, but also in ordinary ship guns of different calibers, which they want to leave mixed with railguns on destroyers Zumwalt. The same ammunition will be used in ground guns.

To make the HVP suitable for guns of different calibers, it will be manufactured in sub-caliber versions with a projectile in the pan for each specific caliber. When the assembly leaves the barrel, the pallet breaks into pieces, and only the projectile flies further. In the 2015 tests, HVP was fired with a caliber of 90 mm and a length of 609 mm. The projectile itself weighs 12.7 kg, and the entire assembly weighs 18.5 kg. The remaining 5.8 kg is the pallet.

The projectile is placed between two conductive rails. The reinforcement protects the rails from direct contact with the projectile

They plan to make HVP projectiles adjustable in flight, for which they will be equipped with a precision guidance module that works with the GPS system. The Americans said that they already have workable electronic systems controls that can withstand overloads of 30,000 - 40,000 g during acceleration, exposure to plasma temperatures of 20,000 - 25,000 degrees and electromagnetic fields ultra-high power. There is evidence of successful tests of such projectiles in 2016. It is expected that full development of the HVP will be completed by 2020, and they will be transferred to series by 2025. The control unit will lead to an increase in the price of the projectile, which in its original (without electronics) version costs 25 thousand dollars. But it’s still significantly cheaper than ship-based guided missiles costing 0.5-1.5 million.

Three grams of monstrous power

The peculiarity of the American approach to the development of a railgun is the gradual increase in capabilities with the consistent achievement of improved parameters: projectile acceleration speed from 2000 to 3000 m/s, firing range from 80-160 to 400-440 km, muzzle energy of the projectile from 32 to 124 MJ, weight projectile from 2−3 to 18−20 kg, rate of fire from 2−3 rounds per minute to 8−12, power of energy sources from 15 to more than 40−45 MW, barrel life from intermediate 100 rounds by 2018 to 1000 rounds by 2025, trunk length from initial 6 m to final 10 m.

Such information is not officially published in Russia, but last year, First Deputy Chairman of the Federation Council Committee on Defense Franz Klintsevich stated that work is actively underway in our country in the field of creating electromagnetic weapons.

The successful tests of a railgun (though not of a combat class, but of a laboratory class) in Shatura near Moscow, which were carried out at a branch of the Joint Institute for High Temperatures of the Russian Academy of Sciences under the leadership of Academician V. Fortov, are well known. A railgun with a barrel length of 2 m fired bullets weighing a few to tens of grams. Russian know-how—preliminary acceleration of a projectile before being fed into the barrel—allows for muzzle velocities higher than American ones. Thus, in January 2017, a projectile made of dense plastic weighing 15 g was accelerated to a speed of 3000 m/s and penetrated a metal target many centimeters thick. Somewhat earlier, a projectile weighing 3 g was accelerated to a speed of 6250 m/s (almost the first in space) and when it hit a steel target, it simply vaporized it.

China, according to press reports, is at the stage of research and development, which is concentrated in the specially created CASIC corporation in the Wuhan Scientific Center (WUHAN). Representatives of the PRC said that they are developing a ground-based railgun similar to the American Blitzer and promise to create a 130 mm caliber gun under Project 055A by 2020.

The Ampere force also acts on the rails, leading them to mutual repulsion.

Story

Term railgun was proposed in the late 1950s by Soviet academician Lev Artsimovich to replace the existing cumbersome name "electrodynamic mass accelerator". The reason for the development of such devices, which are promising weapons, was that, according to experts, the use of gunpowder for shooting has reached its limit - the speed of the charge released with their help is limited to 2.5 km/sec.

In the 1970s, the railgun was designed and built by John P. Barber of Canada and his scientific adviser Richard A. Marshall of New Zealand. Research school Physical Sciences, Australian National University. [ ]

Theory

In railgun physics, the modulus of the force vector can be calculated through the Biot-Savart-Laplace law and the Ampere force formula. To calculate you will need:

From the Biot-Savart-Laplace law it follows that the magnetic field at a certain distance ( s (\displaystyle s)) from an infinite wire with current is calculated as:

B (s) = μ 0 I 2 π s (\displaystyle \mathbf (B) (s)=(\frac (\mu _(0)I)(2\pi s)))

Consequently, in the space between two infinite wires located at a distance r (\displaystyle r) from each other, the magnetic field modulus can be expressed by the formula:

B (s) = μ 0 I 2 π (1 s + 1 r − s) (\displaystyle B(s)=(\frac (\mu _(0)I)(2\pi ))\left((\ frac (1)(s))+(\frac (1)(r-s))\right))

In order to clarify the average value for the magnetic field on the railgun armature, we assume that the rail diameter d (\displaystyle d) much less distance r (\displaystyle r) and, assuming that the rails can be considered a pair of semi-infinite conductors, we can calculate the following integral:

B avg = 1 r ∫ d r − d B (s) d s = μ 0 I 2 π r ∫ d r − d (1 s + 1 r − s) d s = μ 0 I π r ln ⁡ r − d d ≈ μ 0 I π r ln ⁡ r d (\displaystyle B_(\text(avg))=(\frac (1)(r))\int _(d)^(r-d)B(s)(\text(d))s= (\frac (\mu _(0)I)(2\pi r))\int _(d)^(r-d)\left((\frac (1)(s))+(\frac (1)( r-s))\right)(\text(d))s=(\frac (\mu _(0)I)(\pi r))\ln (\frac (r-d)(d))\approx (\frac (\mu _(0)I)(\pi r))\ln (\frac (r)(d)))

According to Ampere's law, the magnetic force on a wire carrying current is equal to I d B (\displaystyle IdB); assuming the width of the conductor projectile r (\displaystyle r), we will get:

F = I r B avg = μ 0 I 2 π ln ⁡ r d (\displaystyle F=IrB_(\text(avg))=(\frac (\mu _(0)I^(2))(\pi )) \ln (\frac (r)(d)))

The formula is based on the assumption that the distance l (\displaystyle l) between the point at which the force is measured F (\displaystyle F), and the beginning of the rails is greater than the distance between the rails ( r (\displaystyle r)) 3-4 times ( l > 3 r (\displaystyle l>3r)). Some other assumptions were also made; To describe the force more accurately, the geometry of the rails and the projectile must be taken into account.

Design

There are a number of serious problems associated with the manufacture of a railgun: the current pulse must be so powerful and sharp that the projectile does not have time to evaporate and fly apart, but an accelerating force would arise, accelerating it forward. The projectile or plasma is acted upon by an Ampere force, so the current strength is important to achieve the required magnetic field induction, and the current flowing through the projectile perpendicular to the magnetic field lines is important. When current flows through the projectile, the projectile material (often using ionized gas behind a lightweight polymer projectile) and the rails must have:

• as high a conductivity as possible,
• projectile - with as little mass as possible,
• - as much power and less inductance as possible.

However, the peculiarity of the rail accelerator is that it is capable of accelerating ultra-low masses to ultra-high speeds (projectile speed in firearms limited by the kinetics of the chemical reaction taking place in the weapon). In practice, the rails are made of oxygen-free copper coated with silver, aluminum bars or wire are used as projectiles, a polymer can be used in combination with a conducting medium, and a battery of high-voltage electric capacitors, which is charged from impact unipolar generators, compulsators, and others, is used as a power source. electrical power sources with high operating voltage, and before entering the rails they try to give the projectile itself as much power as possible initial speed using pneumatic or firearm guns. In those railguns where the projectile is a conducting medium, after voltage is applied to the rails, the projectile heats up and burns, turning into conductive plasma, which then also accelerates. Thus, the railgun can shoot plasma, but due to its instability, it quickly disintegrates. It is necessary to take into account that the movement of the plasma, or more precisely, the movement of the discharge (cathode, anode spots), under the action of the Ampere force is possible only in an air or other gaseous medium not lower than a certain pressure, since otherwise, for example, in a vacuum, the plasma jumper the rails move in the direction opposite to the force - the so-called reverse arc movement.

When non-conductive projectiles are used in railgun guns, the projectile is placed between the rails, behind the projectile, in one way or another, an arc discharge is ignited between the rails, and the body begins to accelerate along the rails. The acceleration mechanism in this case differs from the above: the Ampere force presses the discharge to the back of the body, which, intensively evaporating, forms a jet stream, under the influence of which the main acceleration of the body occurs.

Advantages and disadvantages

• The use of a railgun eliminates the need to store conventional ammunition on ships, which increases the survivability of the ship.
• The relatively small size of railgun shells allows for increased ammunition capacity. However, the size of the system as a whole is not very small, and at least takes up space no less than several medium-sized anti-ship missiles.
• The effective fire range of a railgun is up to 200 km, but it can be argued that the greatest effective range for artillery is 20-40 km, and at a greater distance you either have to use a projectile that is adjusted in flight, or the ammunition consumption will increase many times over.
• The high velocity of the projectile allows the railgun to be used as an air defense weapon. The projectile speed of a promising gun, tests of which were planned for 2016, was supposed to be 6, which is significantly lower than many anti-aircraft missiles(9 M for one of the S-300 V4 missiles), maneuvering the projectile is impossible; in practice, only a speed of 3.6 M was achieved.
• No evidence of effectiveness has been presented for many years, especially in terms of accuracy and destructive force. Moreover, with ultra-long-range shooting, the problem of non-uniform curvature of the Earth, gravitational irregularities, temperature differences and, accordingly, air density, as well as humidity, and many other problems arise that limit the accurate firing of artillery with uncorrected projectiles with a range of a few tens of kilometers.
• Penetration, in particular (at long ranges), and the impact in general upon impact does not exceed the performance of medium-caliber artillery (the speed is several times higher, but the mass is several times less, there is zero explosive instead of many kilograms, the only difference is the increase in range due to the combination of mass, speed and, above all, reduced size, which reduces aerodynamic drag). Projectile kinetic energy when penetrating, it is not transmitted beyond what is necessary to overcome the obstacle precisely due to the high speed of the projectile. Those. if a projectile has 3 units of energy, and 1 unit is enough to penetrate the target, then the projectile punches a hole and moves on with the remaining energy. It has no charge, so all impact on the target is limited to punching a hole in it. True, at very high speeds there are nuances here, but damaging effect they are incomparable to explosives. [clarify] [ ]

Advantages

• Provided that all problems related to real application, such weapons can provide tactical stationary missile defense against non-maneuvering ballistic missiles, or expand the firing range horizon.

US Navy program

Developments in Russia

According to the first deputy chairman of the Federation Council Committee on Defense and Security Franz Klintsevich, work on the creation of an electromagnetic gun (railgun) is actively underway in Russia. It is supposed to be used in astronautics to launch payloads into orbit, but other than these words there have been no reliable facts yet.