NationStates Jolt Archive

...where does the plasma go after the gun has been fired and how is the process repeated? Plus why doesn't the plasma melt through the walls of the gun? Last time i checked ETCs we use on NS don't have magnetic confinement or vaccum. Anyways, any answers?

Another Question.
What IS an ETC gun. Is it some kind of plasma railgun?

ETC guns, short for Electrothermo-chemical, use superheated plasma to augment the ignition of propellant. How they don't eat through the cannon itself is beyond me, and considered a product of NS sience. It's why I avoid the wankhappy ETC guns - they're impractical for a reason.

With that information, I'd say that the cost to create a barrel to hold up against the heat would have to be almost as powerful as the armour of a tank designed to stop an ETC round. And since the barrel would be horribly damaged after each shot...I say anyone using them it PMT is pushing it. In FT i''m sure there's something that will stop it.

Actually Electrothermal-Chemical guns essentially use a high power electrical ignition system taken to the extreme. First of all they dont mean plasma as in the future tech kind, they mean to change a medium nearly instantly from a solid to a gas or to be in a plasmatic state... This allows for an incease in velocity as the propellant is consumed quicker and with less carbon fouling as much more of the actual propellant is ignited in the inital ignition then with traditional rear primed progressive burn systems...

Or atleast thats the Real tech answer, initial experimentation and prototyping was done in the 80's by the British but was never adopted due to increased complexity, weight, logistics, and cost of manufucturefor what is really not all that drastic an increase (at most about 20% increase) it is not a product of NS science, but it has been badly represented by some in the NS comunity...

http://en.wikipedia.org/wiki/Electrothermal-Chemical_technology

Its just more expensive, something us people with 75% defense budgets can work with.

That's what ETC is, its basically using electricity to ignite the propellant. The advantages are that the entirety of the propellant is quickly expended instead of the hammer/primer method which is a much slower process. With an ETC cannon/round you're looking at a much quicker and much more, how do I say it, powerful? combustion of the powder. Its just a near instantaneous combustion which means more initial pressure is present which acts on the shell much, much better than the gradual combustion [which radiates towards the shell, which means the initial gases don't even touch it] hammer/primer method.


However, you could be thinking of electro-thermal, which is what I previously used... Ever used or seen a plasma cutting torch? We have one and I've used it God-knows-how many times. Put the tip to the metal, pull the trigger and electricity arcs directly into the metal and turns it into a plasma state [like a welder, but much hotter and with air fed directly into it to keep it into a quasi-gaseous/solid state]. How doesn't it burn right back through the tip? Compressed air keeps the 'torch' from the tip and feeds it. Pull the tip away the arc disconnects and its cool to the touch. Using an electro-thermal system on a tank, the initial jolt will be so much that the metal will be turned into a plasma state. And as soon as it ignites the arc is disconnected and its back to where it started. Its so quick that it does little damage [over time this changes; I can do it with a plasma torch, if I get the arc and instantly pull away there's nothing but a black mark and a small pit (and I'm not near as fast as a short jolt of electricity {think of a car, at 2400 RPMs with a V8 travelling down a road there are four sparks ignited every revolution, that's 9600 sparks a minute... I couldn't start an arc and pull away in 1/9600th of a minute})] and combine this with the plethora of pressurized gases and its going to contain itself. Others may go so far as actually using a compressed gas system to keep the superheated metal away, but its unnecessary.

Okay, so you gonna use compressed gases to keep hot plasma from damaging walls of the gun tube? Are you kidding me? Gasses store heat, thats what they do, they store heat better then solids. Those gasses will heat up and melt the tube and also there does the plasma go and how is the direction in which it goes determined? Also how can you fire this gun again if you already used up your piece of metal.

The reference to an arc welder (which does use compressed gas to focus the arc and keep it from melting the working tip to the electrode) was merely an example, though relatively accurate. Though the system is not necessary with a true ETC gun.

Plasma in this reference is merely a high voltage spark put through a light metal to act in the same way a primer does on a traditional round.

The plasma (which is really just a continous instant arc of energy) once power is stopped simply ceases to be much like a light goes off when energy is not running through the filimament. The light bulb dosent just explode becuase the filament was at a near plasmatic state and now that plasma has to 'go somewhere' likewise the heat released is only partially hotter than a traditional system (again probably less than 20%) but the effect equals a quicker more consistant burn which equals increased velocity and higher efficency from the propellant.

The 'plasma' dosent propel the round at all, gun powder does, the plasma just acts sort of like a booster charge to an exsploive by accelerating the burn rate and does it along the length of the charge instead of at the diameter. Velocity and Subsequently barrel pressure and heat will not exceed a 20% increase which can be compensated for in the construction of the barrel/chamber.

Or thats how REAL ETC guns work, some on NS may use different variations on the theme (and some just use the name with no connection what-so-ever) but thats the true system works.

The thing is that plasma doesn't just go away, the lightbulb doesn't have plasma in it, it has a piece of metal that burns continuously because the bulb is sealed off and filled with a special gas that dramatically slows the burn rate. That is also how the plasma light bulbs (those long cylindrical ones work) just there is no metal, only gas. ETC gun is a whole over deal, here you have hot plasma and there is no reason for it to go away until it gives off all of its heat energy. I remind you that energy can not be created or destroyed and so the heat energy given off by plasma can't just go poof. This being the case i don't see why that plasma would not damage the gun, although i am not sure as too how much plasma is created in the process purhapse an amount that gives off its energy quickly enough to not damage the gun, but again i don't know that. Is it how the ETC works?

Its just a spark from going laterally along the propellant cahrge so it all lights at once! The "plasma" weighs a tiny amountn, so it doesnt need mcuh energy to make it hot enough to do the job.

A venting system can be activated after the round leaves the barrel, the vent would release the plasma or gasses, wether or not this would actualy work, but either way its only a suggestion

okay i got it everbody, for some reason then i heard plasma and ETC i imagined there being created amounts of plasma on the scales of ITER, okay so just a spark, and all the energy is transfered to the propellant, thats feasible.

What irritates me about ETC guns on NS is that people seem to think they can use a heavier gun design, bump it up to 135-150mm, and then claim a 70 ton weight...

What irritates me about ETC guns on NS is that people seem to think they can use a heavier gun design, bump it up to 135-150mm, and then claim a 70 ton weight...
Amen.

Amen.

Indeed!

OOC:I used to be one of the idiots who use a 140mm ETC gun. But lately I have been seeing a shift away from large caliber ETC guns and towards smaller ETC guns(like 120mm-130mm) with features that increase the power of said ETC gun. I myself now utilise 130mm ETC guns on my Main Battle Tanks.

OOC: I use 126mm Hugh Velocity ETC weapons with EMR systems, i use that calibre because no-one else does and so they can make use fo captured ammunition.