Humanity is missing, luckily I have billions of clones.

Chapter 116 Laser Cannon
Li Qingsong has already mastered electromagnetic cannon technology. However, electromagnetic cannons used for interception and electromagnetic cannons used for attack are two different things.

Offensive electromagnetic cannons pursue lethality, so the projectiles must be as large as possible and as fast as possible. As for the firing rate, of course, the higher the better, but the requirements are not that high.

The requirement for defending against electromagnetic guns is that the projectile must be as small as possible - it only needs to be hit by the incoming electromagnetic gun projectile to deviate from its trajectory by even just one centimeter. After a long journey, it will deviate greatly from its original trajectory, making it impossible to hit the spacecraft. This does not require too much kinetic energy, so why make the projectile so large?
On the contrary, the smaller it is, the more it can carry.

The requirement for muzzle velocity is actually not high, and there is no need to reach a speed of more than ten kilometers per second.

Several kilometers per second, or even less than one kilometer per second, is not unacceptable.

After all, we are intercepting, so we only need to calculate the trajectory of the projectile in advance, and the lower speed can just hit the high-speed projectile.

Defensive electromagnetic guns do not have high requirements for projectile mass and muzzle velocity, but instead have extremely high requirements for firing rate.

In extreme cases, defensive electromagnetic guns must be able to fire hundreds or even thousands of projectiles within a second. Because in a space battlefield, who can be sure how many projectiles will be flying towards them in the next moment?
Following this design idea, Li Qingsong took a lot of improvement measures on the original electromagnetic gun, and finally created a small electromagnetic gun with a barrel of only two meters, a diameter of only 10 centimeters, and a maximum muzzle velocity of only two kilometers per second - even some gunpowder gun bullets with high muzzle velocities cannot compare with it.

The projectiles fired by this electromagnetic gun are extremely small. The lightest projectile weighs only about 2 milligrams, roughly the weight of a small steel ball in a ballpoint pen refill.

Even if its muzzle velocity is as high as 2000 meters per second, its kinetic energy is only a few joules, but it doesn't matter. As long as it can cause the target projectile to deviate from its trajectory by even just one centimeter, it is enough.

The extremely light mass allows a warship to carry a large number of these projectiles. After all, even if there were 50 of these projectiles, the total mass would only be one kilogram.

After completing the development of various types of defensive electromagnetic guns, Li Qingsong turned his attention to laser cannons.

Lasers have an incomparable advantage over physical projectiles, which is their faster speed.

The fastest electromagnetic cannon projectile only travels at a speed of a dozen kilometers per second, while the transmission speed of lasers is the speed of light, a difference of more than 20,000 times.

Defensive laser cannons are more suitable for dealing with projectiles that have entered a closer range and will soon hit the enemy if not intercepted.

At the same time, Li Qingsong also plans to develop both offensive and defensive models of laser cannons.

It would be a waste if such a good offensive method was not used to attack enemy spacecraft.

Laser beams with extremely high energy can not only destroy the target's armor and shell by traditional heat burning methods, but also trigger a certain shock wave effect after quickly heating the target, causing greater damage.

In addition, the extremely rapid heating effect can also destroy the structure of the material, causing it to directly peel off due to rapid high-temperature expansion and low-temperature contraction, thereby destroying the overall structure.

Lasers have a very long history of application and have been used on a large scale in the early days of the human world, but their use in the field of weapons is relatively rare.

The most important thing is that the technology is too difficult.

Weapon-grade laser cannons not only require extremely high-power laser generators, but also extremely high instantaneous power, which places a huge strain on the energy supply system, even greater than that of electromagnetic guns.

In addition, it has extremely high requirements for the cooling system, which is fundamentally different from the electromagnetic gun.

Without a strong enough cooling system, the laser generator may melt itself in less than a second. Another most important factor is the divergence angle of the laser.

Li Qingsong must create a laser with an extremely low divergence angle so that it will have practical significance.

Only when the divergence angle is low enough can the laser beam be sufficiently convergent.

Suppose that when a laser beam is first emitted, its cross-sectional area is 1, and then after transmitting one kilometer, its cross-sectional area becomes 2. It is obvious that the energy received per unit area is reduced to half of the original amount, and the lethality is greatly reduced.

Similarly, decades ago, Li Qingsong had already adopted a clumsy method without any skills, accumulating brainpower and resources, developing at all costs, and iterating and optimizing day after day. Finally, decades later, he developed a laser cannon with certain practical significance.

According to previous plans, the laser cannon developed by Li Qingsong has two major series, one series is defense and the other series is offense.

Under each major series, there are many models based on the laser power, wavelength, etc.

At this moment, Li Qingsong started an experiment on high-energy offensive laser cannon.

One thousand kilometers above Ganymede, a retired Mercury-class battleship is sailing quietly.

Although it has been retired and its technology is outdated, its armor material is still relatively advanced and extremely thick.

It could not be penetrated even by sustained bombardment from high-rate machine guns.

But at this moment, a thousand kilometers away, a laser beam from the surface of Ganymede shone on its armor.

The initial cross-section of this laser beam was only about 3 square centimeters. After traveling a thousand kilometers, its cross-section has only doubled to 6 square centimeters.

Although the area has doubled and the energy received per unit area has been reduced by half, because the initial energy is high enough, it still has extremely high lethality at this moment.

Under the laser irradiation, the metal materials on the spacecraft armor began to boil and explode in just a few seconds. After more than ten seconds, the surrounding armor materials were also seriously affected by the changes here, resulting in a significant decline in performance and extremely reduced protection capabilities.

After half a minute, the thick armor was burned through, causing a large amount of gas to leak out, and the entire spacecraft lost power due to the penetrating damage.

After a comprehensive assessment, Li Qingsong came to a conclusion.

"The power of a ship-borne combat laser cannon cannot be that high. Generally speaking, the largest ship-borne laser cannon can maintain a certain degree of lethality within a range of about 3,000 kilometers. Beyond that, it is useless.

Very good, not bad, three thousand kilometers is enough."

Even if it wasn't enough, there was nothing he could do. This was already the limit of Li Qingsong's skills, and he couldn't go any higher.

After completing the inspection of the offensive laser cannon, Li Qingsong turned his attention to the defensive laser cannon.

(End of this chapter)