The city was thrown there first, with the exploration of the No. 1 world, the various resources in the No. 1 world began to flow to Aurora City, the resources inside Aurora City are now very abundant, since the materials are abundant and the city is now ready to expand, then let's upgrade the city's urban defense to the next level!

Now the city defense of Aurora City is artillery and missiles of various calibers, missiles or something Su Fan has no way to upgrade in a short period of time, and even if it is upgraded, it is useless, she aimed at the artillery, since the reason of the big hand last time, the city has been expanding in the recent period, and they are desperately building large-caliber artillery, these artillery can now be upgraded because they have a large number of new materials.

The next generation of large-caliber artillery is, of course, electromagnetic weapons, the principle of electromagnetic weapons is not a tall thing, the key is the material, one is the barrel material, the electromagnetic gun can easily hit the shell dozens of times the speed of sound out of the chamber, the requirements for the barrel are extremely high, the barrel of the electromagnetic gun is two guide rails, if you are not careful, it will break due to violent friction, or because the resistance is too large, it will catch fire directly.

The second material is the energy supply system, the super destructive power of the electromagnetic cannon is not a joke, there is not enough energy cannonballs and there is not so fast speed, the problem of the guide rail is very simple, it seems to be the so-called superconducting material of the high-end atmosphere on the earth, and it is not considered the bottom end in this world, but there is already one, that is, the magic metal of the thunder and lightning attribute, unfortunately, the magic metal is too expensive in the old world. I couldn't afford it, so the electromagnetic cannon project was put on hold for the time being, and since the development of World One, this project has already begun.

Although the magic metal of the No. 1 world is not like the No. 2 world, you can dig a pit to dig up priceless magic metal, but the magic level of this world is too low, and a lot of magic metal will not be used at all, and the useless things are of course of no value, because the magic metal of the thunder and lightning attribute is relatively rare, so it is collected as a luxury item, but it is a prosperous antique. World One is a standard chaotic world. In troubled times, all kinds of weapons and equipment are much more expensive than luxury goods.

Su Fan designed a 300 mm electromagnetic cannon, it's not that she doesn't want to make it bigger, this cannon can only be said to be testing the waters. After all, electromagnetic guns on Earth are still in the research stage. The cannon was forged from two ten-meter-long wires of full lightning properties. In order to increase the strength, the internal bracket made of titanium alloy should be able to withstand the severe friction of the shells. The cannon's energy supply is a dozen magic power extraction magic arrays connected in series, which occupy a relatively large area, making a 300 mm electromagnetic cannon occupy about the same area as a 1,000 mm conventional artillery, after all, it is just an experiment.

The design principle and design diagram of the electromagnetic cannon Su Fan has already had a draft, the formation of the cannon did not take long, the two reinforced guide rails were firmly fixed in parallel on a platform, the superconducting coil was erected, and the magic array for energy was also carefully depicted, this cannon can only be called an electromagnetic cannon system at present, and it is still not able to fight, so many wires are exposed, and the cannon will be scrapped if there is a slight problem.

The muzzle of the cannon pointed to the sea not far outside the city, surrounded by a circle of onlookers, Xueyu They listened to Su Fan all day long about how powerful the electromagnetic cannon was, and now they were brainwashed and gathered around curiously, wanting to see what powerful these guys who used electricity were.

Su Fan personally put a special shell of 300 mm caliber on the guide rail and fixed it, and finally checked the direction of the magnetic field, in case the direction of the magnetic field was twisted, then the result would be a tragedy, after checking that there was no problem for the last time, she quickly left the side of the cannon, got into the bunker, and pressed the button next to her.

The magic power extraction magic array was connected, emitting a dazzling purple light, accompanied by flickering electric sparks, powerful electrical energy flowed into the electromagnetic cannon system, because the coil of the electromagnetic cannon is made of superconducting materials, and there is no need to be afraid of being burned, Su Fan also let go without installing a fuse, and the powerful current passed through the coil, producing an extremely powerful thrust, which pushed the cannonball that was fixed on the guide rail to rush forward with an unimaginable acceleration.

About a few hundred kilograms of magic crystals in the magic array instantly turned into ashes, and the magic power extraction magic array flashed with terrifying electric sparks, even if it was so far away, Su Fan could feel the trace of static electricity on his skin, and the overly powerful current directly burned the magic array, the composition of the magic array was not a superconducting material, and an unpleasant smell floated out.

Boom ~ deafening explosion, the electromagnetic cannon does not make any sound, but the noise caused by the violent friction between the shell and the track, and the explosion sound when the shell passes through the air are very loud, and after the two noises are mixed together, a violent explosion is formed.

"It's so noisy!meow meow~" Liuli covered her ears and posed in a posture of holding her head and squatting, the two cats on her head also have a sense of hearing, this pair of ears is extremely keen, more acute than human ears, everyone hiding in the underground bunker and eh, only Liuli is uncomfortable.

"Okay, okay~" Su Fan stretched out his hand and hugged his good friend and touched his head, Liuli's favorite thing was this, and he immediately didn't hold his head and squatted to defend, lying in Su Fan's arms and arching around to find a place.

"Let's go, go and see how powerful it is?" Blood Jade is most concerned about this, what Aurora City lacks most now is not a big killer, what Su Fan has here is that now he can enter and exit the black world at will, and he can accumulate a lot of nuclear weapons casually, but nuclear weapons are not sweet potatoes, they can be thrown casually, and the electromagnetic cannon is what the city lacks, as for the laser weapon Su Fan has not considered it, but because of the technical problem, it has not been solved for the time being.

Blood Jade was the first to walk out of the underground bunker, Su Fan followed with Liuli in his arms, the twins didn't understand what it meant, but they just felt very powerful and followed.

Su Fan carefully observed this electromagnetic cannon device, under the violent friction, the guide rail of the titanium alloy was not damaged, but the high temperature was scary, and there was no resistance coating here, so it could only be put on first, anyway, the electromagnetic cannon was not used for large-scale bombing, and it was nothing if the magic array for energy was burned, as long as the power of the cannonball was enough, it would be good if the magic array was made into a modular shell, and it would not cost much anyway for a few magic arrays.

Through the velocimeter placed in the muzzle, Su Fan saw an astonishing figure of 3,400 kilometers per second! 10,000 times the speed of sound! Looking at this data, she was not calm at that time, she immediately searched in the direction of the muzzle, and sure enough, she found a lot of metal debris near the muzzle, these metal debris are nothing else, it is the tungsten steel alloy shell! At 10,000 times the speed of sound, the resistance of the cannonball and the air directly tore this shell, which is harder than the armor-piercing warhead of a tank!

"Did you succeed?" Blood Jade's understanding of the electromagnetic cannon is still at the level of an electromagnet, and he can't see a reason at all.

"It's a success," Su Fan said, grabbing a fragment of a cannonball, it looks like it needs to be improved

The power of the electromagnetic cannon is too great, it needs to be improved, after Su Fan sent the people around him away, he began to think about this electromagnetic cannon system, and after thinking for a while, he began to do it, first of all, the positioning of the electromagnetic cannon is aimed at some elusive masters, sniping them at a distance, then the caliber is not too big, plus the energy supply magic array is burned once, it is simply made into the existence of a shell, large-caliber artillery needs a larger volume of shells, if it is a small-caliber artillery shell, it can be made into a whole, increasing the firing speed。

In the end, the stereotype of the electromagnetic cannon is seventy-five millimeters, if the caliber is small, the killing is insufficient, if it is large, the shell alone cannot fit such a large magic array, and the final seventy-five millimeters is the most suitable, considering that the previous shell disintegrated because of the speed was too fast, she had to reduce the speed of the shell, only 5,000 times the speed of sound, so that the shell of the shell also became smaller, the size of this shell is no different from the general shell, but the warhead is a more slender armor-piercing shell style.

Science and technology is towards the two extremes of mega and miniaturization, the seventy-five mm electromagnetic gun is not considered a giant nor a small, so the technical content is much lower, the first sample gun was quickly manufactured, and the test was completed, the life of this small-caliber electromagnetic gun is relatively short because of the friction, a cannon hit a hundred times the guide rail will be seriously worn, and the new guide rail has to be replaced, and because the heat generated by the violent friction needs to be dissipated, the electromagnetic gun only fires once in ten minutes, for only 75 mm artillery, this speed is too slow。

It is precisely because the rate of fire is too slow, the city's defense system needs to install multiple electromagnetic guns to form a relatively complete defense network, this is a big siege, electromagnetic guns have high requirements for accuracy, many key parts, similar to coils or something, need Su Fan to do it himself, man-made machine girls can't do it.

Small-caliber electromagnetic guns have been successful, large-caliber electromagnetic guns and high-rate electromagnetic guns have also entered the research and development agenda, this is not a matter of proportional amplification, you must know that the same material, the larger the size, the relative strength of the relative decrease, if the material of the 75mm gun is used to make a thousand mm cannon, it is the best outcome to be directly torn apart by gravity. (To be continued......) rt