 So hello, I'm Xinxian, so today I'll be presenting on my hybrid operational railgun. So a pair of backgrounds, so everyone votes year 5 or JC2 in JC1 in my school will have to do a research project. So I chose to do one in the railgun. So firstly, a background on how railguns work. So railguns consist of a pair of rails with a projector in the middle. Current is passed from one end to the other, setting up magnetic field and the projector experiences along its path ends from that course. So railguns are really cool. The projector is moving so fast it's breaking the sonic barrier and you can see the plates at the back which are actually plasma due to the very high temperature that's produced by the railgun. So railguns are really awesome. They have very high model capacities compared to their gas expansion guns. While containing no explosives, so they are very safe. And also they are very low cost because you don't need to guide it, no need to calibrate for wind or gravity because it's so fast, you just have to point and shoot and they are just switches. And compared that to the Tomahawk missile price which is really expensive. But we are not using them now because of their very low real life time due to the high physical stress and temperatures with railgun rails experience. So this results in new requirement, frequent maintenance for the railguns and stuff and no one to this date has been able to demonstrate firing multiple full power shots from the same set of rails yet. So this is a major thing that's holding railguns back from their various applications. So firstly an introduction of various railgun armatures. The two most common railgun armatures are the solid and plasma armatures. The solid armature is where the projectile needs to contact the rails for currents to pass through and the plasma armature is in fact they replace it with plasma so the current passes through the plasma state which then pushes for a solid non-conductive projectile. And now I will introduce the hybrid armature which is a combination of both the solid and the plasma armature where you have a small gap that the plasma arm is used to carry the current across. So we can compare the various drawbacks of the systems and the hybrid armature railgun actually has the best of hopefuls as it has the least stress on the rails as it only needs to carry high current used with a small arc like low efficiency, it looks cool enough, but high power consumption like all real guns. So like we saw when we first started out to design the gun our main concern was that we had to maintain a constant small gap between the rails and the projectile while being able to sustain the plasma arc. So for that our answer to that was specially designed gun law. The projectile has been inserted into the wall already so you can see the gaps between the projectile and the rails which is a 0.5 mm gap and the copper rails copper shouldn't because of low resistivity at high current point Teflon guides to guide the projectile into straight line through the wall and G10 casing to hold everything together so you can see the wires which are actually the input and output of the current. These are also our projectile, 151 is very expensive it was precision engineered to have the guides also the point of takes which helps to concentrate electric fuel so plasma can arc easily so less voltage required. So the first thing we did was to check if the plasma can actually arc so we are brushing G10 gas through it and the blue spots are the plasma arcs. So this was about 400 volts I think so we are proof that we can get the plasma arc at 400 volts with G10 gas. So the next thing we had to do was to be able to sustain the plasma arc while the projectile was in the wall so you can see the normal capacitor discharges and the negative exponential decay function and what we need to sustain the plasma arc is actually a flat arc, current arcs so our answer to that was the pulse forming network which was a network of capacitors and inductors by using this system we can output a flat cloud waveform and the first capacitor discharges through the inductor the inductor resists high current pulse and so the first current output is left lower and then as the capacitor starts discharging less and the current drops the inductor will then convert the magnetic field back to its current so this maintains the flat top allowing us to get the square pulse So to construct a remnant circuit simulation in L.E. Spice 4 and then construct a flow of field so we can see our gravitate capacitors and inductors the capacitors are related for all 3 1.6 kilobots, 200 microvora and I don't remember but it happens So now after we've made our PN band the first thing we had to do was to check that it actually works so that was our idea to check that it works when we call it a PN, so a thyristor and call if it's inside and we discharge it through a one-bomb resistor and we have a single generator to signal the thyristor So yeah, it sounds great and what actually happens is that it discharges into a single generator but never mind if you've got results anyway for the PN band so we can compare our actual current waveforms to that and simulate the current waveform so our current waveform is very promising this is about 900 amperes per second so yes, our PN band works we can shoot the gun now so what we thought was as well as we put the projector in the middle charge the capacitor, flash it in there it shoots no more switching circuit, no more exploding single generators but then life isn't that easy so what happens is that when we charge the capacitor plasma starts arcane so it breaks down and then the projector stays there, it doesn't move so we had back to the switching circuit again so it's mainly good again so no more single generator we replace it with an Arduino megastar and then we put a resistor there hoping it would actually stop it from dumbing and then what happens? the exact same thing so we did it a lot of times until finally after a 4-dike did Arduino switch got the 5th one working and it actually works so this is a circuit diagram of the complete railgun system over here is the PN band which is charged to 1kV and then Arduino will know which is in single input from the button and it's capable of signaling two amplification circuits the first which is signaling the thyristor which then allows the PFN to be charged into the railgun and the second which signals the gas injection circuit which will flush the EDM gas into the railgun bore so this is the complete railgun system so firstly we inject the projector through the feed port which is the fancy ports of all the railgun and also as the gas injector and then the capacitors are charged then we inject we trigger the gas injector and the solar system gas also pushing the projector into the railgun bore and then we trigger the thyristor allowing the PN band to be charged into the railgun and finally the railgun fires so here's a video so we used light dates to measure the scale of the projector we shorted it with both hybrid and solid armature we had a pull-up which contacted the rails so we can compare the speeds and what happened with the solid armature it just feels to the rails when we try to shift it and the efficiency is not important like from discussions so we can see that the hybrid armature railgun experienced far less frictional losses and also the solid armature feels to the rails feels to the localized seating at the contact point between the rails and the projector when 1 kV passes through that so it kind of came out and stuck together and our small railgun could not provide enough force to overcome the fusion so you can imagine in big scale railguns how much damage is being sustained by the rails also most importantly our hybrid armature railgun tends to fire repeatedly with minimal damage to the rails so when I next seen the image the damage sustained by the rails after we fired it a few times which is quite minimal and it could still fire without any compensation so a congenial is through this project we have proven the feasibility and effectiveness of hybrid armature railguns in reducing railgations, frictional losses and hence allowing us to lengthen rail lifetime and increase the mass of velocity so then we hope that this can allow railguns to be used in more industries for example NASA is hoping to use railguns to launch stuff to lower for a bit can be used in fusion reactors and of course weaponry systems so what I learnt from this project is that we must respect high power we've burned out a lot of stuff and nothing ever was on the first try also our mechanics were extremely expensive because it was more than twice as the cost of the railguns singing and like 5 argynovas anyone has any idea what you can do with burn argynovas it's okay and we all have fun so let us end off with a