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Is an FGMP round radioactive?


SOC-14 1K
I'm just skimming through my FF&S, and in the Maneuver Drives section it mentions the Fusion Rocket as basically a fusion reactor with a hole in it. It mentions that the exhaust is particularly horrible and radioactive.

Then, reading about the High-Energy weapons, and how essentially a PGMP uses a laser to heat hydrogen until reaches a plasma state, and then opens up a hole, whereas an FGMP waits for fusion to start before that happens.

So, if a Fusion Rocket is nasty and radioactive, why isn't a Fusion gun?
Shrug. Because it works by Handwavium? Realistically, a fusion gun would (a) irradiate the user, and (b) have an effective range comparable to its primary blast radius.
Yeah, I think I'd treat both the fusion and plasma guns as more of a grenade launcher type weapon. The fusion or plasma is sent downrange in a magnetic bubble that detonates at the specified range. This protects the user from all the nasty stuff but imparts quite a kick in the early versions, hence the need for the battle dress. A similar description should be used for the bigger versions too, and so they should all have a magazine component for the magnetic bottle smart round. The great thing about this smart round is like the one in development now, if the bad guys are behind hard cover just set the round to detonate a meter past the cover and put it over the wall, boom, no more bad guys.

But that's just off the top of my head. It probably needs a little fine tuning.

Now then, an analog weapon to the fusion drive would be a fusion type flame thrower
Originally posted by far-trader:
Now then, an analog weapon to the fusion drive would be a fusion type flame thrower
Finally! A valid excuse for Zhodani warbots! :D
Whartung asked: So, if a Fusion Rocket is nasty and radioactive, why isn't a Fusion gun?

Should be, isn't somehow, go figure.

Oh, that's right. It's a game!

If it really drives you and your players batty, do what I did in my ancient campaigns; throw the FGMP out. There are FGMPs in the OTU, there are none IMTU, and whether they work IYTU is entirely up to you!

Have fun,
Hi !

Perhaps You can consider that as a marketing bluff of TUs weapons industry

As Anthony already stated, a significant fusion reaction turns the firing person into the center of a primary blast radius...
So, a very, very tiny and clean (products are not radioactive) fusion reaction (around 0,000000001 g deuterium) should be able to produce enough additional energy to "level up" a standard plasma gun to a "fusion gun". One of those handwavium material protectors takes care for the created fast neutrons, but is activated slowly and has to be replaced from time to time...

OTHO, if plasma and fusion guns speak, would anybody care for some bits of radioactive pollution anyway :( ?

The officials provide misinformation about the dangerous side effects of these weapons...

Besides, in TNE the velocity of the plasma bolt is given with 8600 m/s.
For those with a higher weapon skill level than me (guess, everybody): doesnt a corresponding recoil kill the firing person, too ?


All I've been able to find is that they produce intense heat (infrared radiation) and a kinetic kick. The kinetic kick is because it's matter accelerated to 8600 meters per second (don't ask where they got that number - that's what it says) and gravity compensated for recoil. Nothing about Gamma, X-Ray or other damaging and possibly genetic-altering radiation. Maybe it's just low enough radiation to not make a difference with the extreme heat involved - solar fusion is over 1 million degrees. The fusion bolt would melt just about anything in it's path. Maybe the secondary damage is not enough to pay attention to.

The Engineer asked: "...doesnt a corresponding recoil kill the firing person, too?"

Recoil is a matter of momentum (=mass x velocity). Even at the very high velocity, if there's a miniscule mass, the recoil could be manageable. The projected bolt's kinetic energy (1/2 mass x velocity squared) will still be large because its velocity is so high.
Sir Daemon, thanks - I especially forgot the gravity compensation.
But with regard to wombles answer...does anyone have some idea about the projectile mass or the kinetic energy involved, when talking about a P/FGMP ?

And for the weapon geeks:
I found a site, where they calculate the recoil energy with 0,5 * p^2 / <Weapon mass> where p is the momentum given with <projectile velocity> * <projectile mass>.
Is that somehow correct ?
I would say the Engineer has the answer to your mass question: around 0.000000001 g deuterium. You're not going to get a lot of recoil, or kinetic energy out of that. Of course, since you're setting off a very tiny H-bomb, you don't really need "kinetic" energy.

I think we used the magnetic bottle idea when I played in college, too.
Originally posted by Andrew Boulton:
The firer is generally in CA/BD, which will shield them, and the target is dead anyway...
Well, I just look at the folks complaining about the use of DU rounds in the A-10's and M-1s, and the residual effects of that, and think about these guys running about tossing small H-Bombs at each other.

While the combatants may well be protected, there would I guess be long term effects on the battlefield.

Now, it can be argued that they have radiation cleanup issues ANYWAY. I mean, if you have a catastrophic hit on a fusion reactor (on a vehicle, for example), there will be ...umm... consequences anyway. So, maybe it's a non-issue and simply rendered as a cost of doing business.

Also, the PLASMA rounds wouldn't suffer this problem, as it's simply that -- hot owie plasma.

As for acting as a grenade launcher, sure, whatever. I've always visioned it as a bolt-o-energy rather than a hose, but having the containment fail on the fusion reaction when it hits (which is, of course, a design goal) I would think would release all sorts of nasty things besides blobs of heat. The Fusion and Plasma rounds already have rules for Splash damage as is anyway.

Leave it said that a) I wouldn't want to be in CQB with a Fusion gun, and b) I wouldn't want a few squads running through my neighborhood blasting away at each other with them either.

Of course then there's the "Nuclear weapons are bad, but damaged Fusion Reactors going critical are Okey Dokey" conumdrum.
Originally posted by Fritz88:
I would say the Engineer has the answer to your mass question: around 0.000000001 g deuterium. You're not going to get a lot of recoil, or kinetic energy out of that. Of course, since you're setting off a very tiny H-bomb, you don't really need "kinetic" energy.

I think we used the magnetic bottle idea when I played in college, too.
Yeah, the recoil has to be due to something else. Like you I figured it had to be a magnetic bottle round, and so of course the idea of plasma/fusion grenade and launcher
I should look at FF&S again, it had a low tech plasma bazooka as I recall :D
You're also not going to get a lot of energy from that miniscule amount. 0.000000001 g is maybe an atom or two. It doesn't even register on megaconverter.com. IMTU, the FCMP uses between 1g and 10g of hydrogen. You also have to remember that once it heats up, it's gas and gas disspates very quickly in atmosphere - especially with that much of a temperature difference. This gun wouldn't be much use long range without some handwavium. There's nothing to hold a magnetic bottle in place once the Fusion Bolt leaves the nozzle of the gun as well. Picture one or two Bolts flying and a lot of steam in the area obscuring the battlefield. In reactive or corrosive atmospheres, that could be very dangerous. A methane planet could possibly have it's atmosphere burned off - well, maybe not without oxygen, but you get the point. These things are dangerous. Something at most the size of a fly (and probably smaller) and as hot as the sun traveling at 19,237 miles per hour (8600 meters per second - that's Mach 26). Almost hard to comprehend. The thunderclap alone would shatter eardrums. Civilians wouldn't stand a chance. This gun is THE definition of shock and awe.

I hope no one ever makes one,

That's 10^-8g, and about 3x10^16 atoms of deuterium. The maximum yield of D-D fusion is on the order of 2x10^11J/g (antimatter is 9x10^13J/g), so you can get a couple kilojoules out of that. A more likely figure for the actual amount of fused material is about 10^-6g. The amount of plasma produced, however, may well be several grams.
I think you misunderstand my take on the magnetic bottle/grenade design Dameon. The magnetic bottle is maintained by and within the body of the grenade. Which also has all the smarts and guidance.

Basically the "gun" is for launching the "round" down range. The backpack produces the plasma or fusion which is then capped by the round which then takes over the containment by magnetic field and it is fired. As mentioned, this of course means the weapons need a bit of redesign to include the expendables for the rounds but it could be part of the power pack.
So Dan it'd be more like a gauss styled accellerator rifle firing a magnetic bottle cannister of plasma in a Fusion state that (somewhere downrange) explodes either by impact or proximity or time delay smart fusing?

Rather than a heating exciting pressure chamber that excites the plasma to a fusion state then opens a valve and lets it squirt down the barrel in a short stream?

Sounds more logical to me. I've always thought plasma and fusion guns were munchin weapons anyway but then I ref TNE and so generally play with a lower tech spectrum anyways
Yep, pretty much bang on Badbru. Thanks for the succinct description

I'm collecting my thoughts on the idea and will post them later in the IMTU forum.
If you keep the "Bolt of Fusing Plasma"; plasma and particulate radiation are, if not identical, very similar save for temperature, density and amount of charge.

Now, if I hit you with monatomic hydrogen and/or helium at 8600 mps, some of that will penetrate similar to alpha and/or beta radiation. not much, but some.

Now, if I make that plasma-hot, most of what gets "radiated" will be steam-exploded off the surface.

Fusion gun is a misnomer: it merely mens its begun to fuse before being fired, not that it's fusing (and thus producing serious gamma, x-ray and such, as what's in the gun is probably shielded from the user, and doesn't corner well..). The fusion byproducts of Neutrinos are not a big deal, and the alpha, beta, and neutron radiations don't tent to penetrate solids very far, again, they focus forward due to weapon design, but really aren't an issue to the target.

Now, those Fusion rockets probably have far higher exhaust velocities (they are probably several tens of kilometers per second, to match the size and fuel rates), so at lest an order of magnitude higher, and probably contain far higher ratio of alpha and beta particles (sustained fusion, rather than monetary). Likewise, the fusion rocket focuses back all the gamma, x-ray, IR, Visible, and UV that it possibly can (aside,possibly) from small windows for photovoltaic conversion to power), for both safety and that little extra efficiency (it's often easier to reflect than absorb EM radiation).