Your "research report" is hard to read IMO.
Yeah, I get what you mean.... the "briefing" is actually a condensed list of idea stubs and talking points that I dashed off in a story format and, months later, it's turned out to actually be rather dense and obtuse to innocent bystanders.
The core of my idea was to reproduce the effects of the weapon as it exists in the game and are described in the story with a much simpler implementation. I say game *and* story because the two are a bit divergent at the moment and grow more amd less so as work progresses.
And this addresses another concern: the devs have often indicated that they're going to be working and reworking this stuff anyways... so might as well offer a plasma fix now for when they get around to the subject again.
A more considered rewrite is needed and I will drop the "report" motif and give a list of proper options.
Done...
Plasma and the Game
Plasma weapons, long a staple of SF military stories, actually would not work in any of the variety of ways that text and visual media have depicted.
Plasma is very energetic and by definition will expand very rapidly and as the plasma supplied by even industrial plasma burners and cutters is very tenuous it could not travel far without completely dispersing. In an atmosphere the effect is much worse as collisions with air molecules would immediately drain the plasma of its energy and thus revert it to normal matter.
So while actual plasma can indeed have very profound effects on ordinary matter these effects are applied by devices or natural forces (such as lightning) that constantly replenish the plasma at point-blank range from the target.
The classic SF description of a plasma hand weapon would require a very, very dense high-energy plasma somewhere between the plasma described above and the kind of plasma not often found outside of stars or detonating nuclear weapons... extreme heat and severe recoil would be the result and when that plasma hit an atmosphere all that energy would promptly be deposited in the air right in front of the weapon.
Not good.
These problems have been known for decades, actually. The original Traveller SF roleplaying game tried to get around them by having their (admittedly much more boisterous) plasma weapons use a boremounted laser to punch a hole through the air to channel the plasma while requiring the troop firing the weapon to be wearing powered armor to handle the heat and recoil... and it still wouldn't have worked.
The current plasma weapon concept in UFO:AI tried to steer around all this by postulating a temporary plastic shell that would protect the plasma en route to the target. Unfortunately this means that a similar material would make an excellent ablative armor against that same plasma.
The latest workaround to the problem that has been offered is having the shell material actually be a high-temperature superconductor that contains the plasma within magnetic shields without touching it... and thus not requiring that the shell be strong enough to withstand contact with the plasma.
This concept gets us further along but invokes problems of its own.
One is that when the sphere impacts the target only a small portion of the plasma will interact with the target while the rest deposits its energy in the air in front of the target. And even that intense of a plasma, say it's a hydrogen plasma contained in the volume of a six inch sphere, even that cannot dump enough energy to the air to generate the weapons effects described in-game.
Another problem is that this superconducting magnetic sphere will definitely interact with its environment... and not in ways that are conducive to traveling far or even hitting the target. Magnetic, electromagnetic, electric and electrostatic fields will interact with the sphere... and surely those pesky humans will put that to use in their defenses.
You can change the conditions somewhat to make the plasma more effective, of course. Making it denser, hotter, possibly of a different element and making the containment sphere stronger to match. But since you're starting from the choice of plasma as a weapon then you're starting from a selection that just makes a poor projectile weapon. By the time you get to where you want to be weapon effects-wise you are essentially firing a blob of extremely superheated goo that must be protected from the atmosphere by magnetic shields that would have to be at least several tesla in strength.
And even one tesla is a LOT of magnetic field. What happens when that sphere passes by a steel-framed building or over railroad tracks or under high-tension power lines? Nothing good. And don't forget gravity losses. And again, it won't take long for humans to notice all this and begin rigging countermeasures of their own.
Barring something new being introduced it would seem that plasma just is too much trouble to make work in a plausible manner for the desired effects.
The core of my idea here is not to just toss out the concept but instead to reproduce the weapon and the effects of the weapon as they exist in the game and are described in the story... but with a much simpler implementation.
Since the weapon effects actually resemble the combination of a blowtorch on steroids and a cranked-up flamethrower, all somehow projected over a distance, the simplest solution might be to have a non-plasma substance cross the distance and cause the desired effects.
Such a substance would be difficult for human technology to currently implement but the aliens have a ready-made concept that can be adapted: the 'alien materials' that compose their ships.
But it's a bit too early in-game to introduce those materials so we introduce instead a subclass of the materials that is tailored to produce the weapon effects but does not allow humans to immediately begin churning out nanocomposite armor and alien aircraft plating.
One limitation is that without being enclosed in an appropriate container with a power source these materials would promptly decompose into nanoparticles of their constituent elements... and thus become useless.
So alien materials that do not decompose, such as those in UFO hulls, would be a later and more advanced research subject.
So... what the device would actually fire starts out as a carefully engineered pellet of dense synthetic compounds hitherto unknown to humans.
The pellet is stored in a magazine that has a power source (one heck of a remarkably compact power source, actually, but that comes out a bit later) which feeds a mechanism that prevents the pellet from decomposing.
The pellet is moved into the firing mechanism, which also contains antidecomposition gear. The heating and firing effects require that the pellet not be in contact with the weapon while it is being primed and fired so the pellet needs to be suspended in the firing mechanism.
The compounds are not particularly magnetic so they can't be levitated that way. Microscopic jets of carbon nanotube particles can do this and the CNT can survive the environment long enough to be effective. CNT particles are already known to humans and thus this use does not affect gameplay.
And, not coincidentally, all this stuff so far royally jams up flamethrower engineering
So the pellet is suspended while it is heated to thousands of degrees centigrade. The exact temperature depends on the firing settings of the weapon but the exterior of the pellet never achieves plasma temperatures and instead becomes nearly fluid while the interior becomes even hotter.
When the pellet is ready to fire a curtain of CNTs is sprayed behind the heated mass and then the CNTs in the curtain, and incidentally the CNTs in the supporting jets, are rapidly accelerated forward by the weapon via magnetic and electrostatic fields generated between the two "prongs".
The nanotubes impact the mass and transfer their kinetic energy into it. The exterior of the mass then becomes a fluid while the core of the mass expands and tries to vaporize but can't quite get there. But the pellet does swell into an orb and that orb is moving. Fast.
A fast-moving superheated orb of fluid in that it would vaporize itself if not for the carefully engineered alien materials effects holding it together. (still van der waals forces?)
A fast-moving orb of fluid that glows blue because it has a core that is beyond white-hot.
And thus is formed the "bolt" as seen on PC monitors everywhere.
The CNTs are either dispersed by air or destroyed by contact with the bolt. This means that the bolts cannot be easily deflected by the same means that launched them.
An added effect is that at close range the propelling CNTs can cause nasty "powder burns" to a target, increasing the damage.
Upon impact the sphere finally gives way and stuff is flying everywhere. The various compounds in the bolt have been engineered to have a variety of effects including penetration, explosion and enhanced splash effects. And it's hot enough to burn through armor.
And the troops still call it plasma...
Edit: tried to make it into a proper proposal and appended it here.