Photon Torpedoes and Warheads

[The Silence and I]

I was thinking about firepowers and the examples of environmental destruction used to calculate yields when an idea struck me:
It is canon the photon torpedoes use antimatter-matter warheads meaning most (something like 70% IIRC Mike's page on Torpedoes) of the released energy will be gamma rays--these really don't interact all that much with materials of normal density. I've read that a gamma ray can be expected to penetrate 16 feet of solid concrete, which brings me to my point; we can measure how much energy it may take to shatter/melt/vaporize an asteroid of a certain size, but shouldn't we also consider how much of that energy will pass through the target before deciding total yield? Particularly as shields ought to absorb these gamma rays? Also, couldn't this account somewhat for visually unimpressive torpedo detonations?
If someone were more knowledgeable on the subject perhaps it could be determined approximately how much energy fails to effect rock or iron asteroids?

[Kazuaki Shimazaki]

Take the Pegasus episode. The target is something like 5 kilometers wide. If gamma rays only penetrate 16 feet (about 5m) of concrete ... concrete isn't all that much denser compared to rock, and you are taking kilometers of rock here.

And you really may not win that way. Watch this logic sequence (I made it up quick, so it is probably flawed, but try it for size:)
1) According to the DESB, superlasers fire neutrinos. And the BTM CD suggests that superlasers are really just scaled up turbolasers, so by that logic turbolasers also fire neutrinos.
2) Neutrinos have murderously high penetration (I think the mean free path against normal Terran matter was like 6000LY) and corresponding low interactivity.
3) Shields do seem to stop TLs, so they must have a high interactivity with those neutrinos.
4) So when we watch things like Alderaan, asteroids, BDZs, and the like, we have to take this low interactivity into account.
5) I don't even want to imagine the results of this.

Just some food for thought.

[Laird]

Kinda off topic, I was watching voyager today. There was some kind of torpedo/missile thing with artifical intellegence, 7 of 9 said it was some kind of high explosive anti-matter weapon.

Point is , it wasn't any bigger then a standard photon torpedo and the quote was something like this "The blast radius of 200km, radiogenic particles blah blah blah."

Is it possible to assume that a weapon of similar design and size could mean a PT could be as powerful?

[Gandalf]

Kinda off topic, I was watching voyager today. There was some kind of torpedo/missile thing with artifical intellegence, 7 of 9 said it was some kind of high explosive anti-matter weapon.

Point is , it wasn't any bigger then a standard photon torpedo and the quote was something like this "The blast radius of 200km, radiogenic particles blah blah blah."

Is it possible to assume that a weapon of similar design and size could mean a PT could be as powerful?

Perhaps they have some sort of distribution method?

It seems it was designed for planetary targets, so the warhead my break into seperate pieces?

[Sarevok]

The highest accepted yield of a photon torpedo is the 64 megaton value from the TM.

[Rogue 9]

The highest accepted yield of a photon torpedo is the 64 megaton value from the TM.

Yes, yes, we know this. But if this torpedo sized object had that kind of power, what's to say the Feddies couldn't steal the warhead technology and load it into a torpedo tube to use? (I'm not sure if I agree or not, I'm just clarifying what I think he's saying.)

[Stormbringer]

The highest accepted yield of a photon torpedo is the 64 megaton value from the TM.

Yes, yes, we know this. But if this torpedo sized object had that kind of power, what's to say the Feddies couldn't steal the warhead technology and load it into a torpedo tube to use? (I'm not sure if I agree or not, I'm just clarifying what I think he's saying.)

The simple fact that they probably have little to no contact with the people that built it, and there is still the major hurdle of reverse-engineering it if they stole it. A roman soldier could still an few rounds of 9mm ammo, that doesn't mean he can make them.

[Rogue 9]

Well that's why I don't agree with him fully. I was just saying what I thought he meant, since it didn't seem very clear to me.

[Uraniun235]

Oh, I remember that damn episode. Hell, I thought it was even smaller than a torpedo (since a torpedo is large enough to accomodate a whole man).

Simply put, that technology is superior to Federation weapons technology; IIRC, those things were warp capable and had a range measured in lightyears. That in itself would require quite some amount of fuel in addition to the warhead itself. My guess would be that they're packing a lot of antimatter in really densely.

[The Silence and I]

Take the Pegasus episode. The target is something like 5 kilometers wide. If gamma rays only penetrate 16 feet (about 5m) of concrete ... concrete isn't all that much denser compared to rock, and you are taking kilometers of rock here.

And you really may not win that way. Watch this logic sequence (I made it up quick, so it is probably flawed, but try it for size:)
1) According to the DESB, superlasers fire neutrinos. And the BTM CD suggests that superlasers are really just scaled up turbolasers, so by that logic turbolasers also fire neutrinos.
2) Neutrinos have murderously high penetration (I think the mean free path against normal Terran matter was like 6000LY) and corresponding low interactivity.
3) Shields do seem to stop TLs, so they must have a high interactivity with those neutrinos.
4) So when we watch things like Alderaan, asteroids, BDZs, and the like, we have to take this low interactivity into account.
5) I don't even want to imagine the results of this.

Just some food for thought.

1)You would get more penetration than that, an engineer can expect a single gamma ray to penetrate 16 feet, so only a few gamma rays are lost every 16 feet or so--sure the asteroid in Pegasus may have eventually absorbed all of the energy, but my thought is that a significant percentage of the energy became wasted heat. If all the energy is absorbed by the rock within a few dozen cm of the surface then you will get significant mechanical energy from heat, if that same energy is spread out then joules per cubic cm decreases and some amount of the energy becomes useless heat. e.g. rather than mostly vaporizing the surface layer and shattering the rest of the 'roid, a you get less vaporization at the surface, but more of the interior is heated. In other words, if you think about this as a heat engine, spreading the energy lowers the efficiency--same energy goes in, less work comes out.
2) DESB? This is the first time I have heard anything about neutrinoes comprising the damaging portion of a turbolaser--why in the bloody blazes of hell would anyone design a weapon requiring several orders of magnitude more energy input than you get for output??!!? I would double check all your sources on this one if I were you. That's even worse than trying to kill someone on Earth at 2000 yards with an election beam...

[Kazuaki Shimazaki]

1)You would get more penetration than that, an engineer can expect a single gamma ray to penetrate 16 feet, so only a few gamma rays are lost every 16 feet or so--sure the asteroid in

We need Durandal or Darth Wong or somebody like that in here. But Quickie quote on Gamma Rays:

gamma ray
The highest energy, shortest wavelength electromagnetic radiations. Usually, they are thought of as any photons having energies greater than about 100 keV. (It's "gamma-ray" when used as an adjective.)

From http://imagine.gsfc.nasa.gov/docs/dict_ei.html

Also, look at the table here for HVLs with various energies.
http://www.ndt-ed.org/EducationResource ... ndepth.htm

Even at 2000keV, HVL is only 2.45m versus concrete. That means if I shoot one million gamma ray photons at concrete, 2.45m in, 500,000 of them would have collided with enough to be transformed into heat.

I think your number is also a HVL, albeit at higher frequency (mroe energetic.) 16 feet is about 3m, so 3m deep, you would lose half. 6m deep and you lose 75%, and by the time you are 10m deep, about 90% of the gamma energy would be deposited in the concrete.

The heated sphere thus expanded a little, to about 10m in radius. The onus is on you to show that made a HUGE difference.

Pegasus may have eventually absorbed all of the energy, but my thought is that a significant percentage of the energy became wasted heat. If all the energy is absorbed by the rock within a few dozen cm of the surface then you will get significant mechanical energy from heat, if that same energy is spread out then joules per cubic cm decreases and some amount of the energy becomes useless heat. e.g. rather than mostly vaporizing the surface layer and shattering the rest of the 'roid, a you get less vaporization at the surface, but more of the interior is heated. In other words, if you think about this as a heat engine, spreading the energy lowers the efficiency--same energy goes in, less work comes out.

The onus is on any Trekkie who wants to produce a bigger number to evaluate the likely loss mathematically and do the work himself.

2) DESB? This is the first time I have heard anything about neutrinoes comprising the damaging portion of a turbolaser--why in the bloody blazes of hell would anyone design a weapon requiring several orders of magnitude more energy input than you get for output??!!? I would double check all your sources on this one if I were you. That's even worse than trying to kill someone on Earth at 2000 yards with an election beam...

It is the Dark Empire Sourcebook, Chapter 9, Planetary Shields section.

That's what it stated, and it is absurd enough that very few take it too seriously. Nevertheless, it is official, and since you are talking about counting the inefficiency into account, I decided to half-jokingly whip it up to show you what might happen if we went down that road.

[Darth Wong]

Gamma rays are highly penetrative, but the depth of penetration is statistical, and varies with density and temperature. That's why the air around a nuclear weapon becomes fairly opaque to X-rays during the initial fireball formation.

As for efficiency losses, they are not an issue. Any reasonably-sized solid target can be assumed opaque to gamma radiation for the purposes of weapon calculations, and there is no such thing as efficiency losses to "waste heat" when the whole purpose of the weapon is to heat up the target.

[The Silence and I]

Alright, that answers a few questions I had. I had thought gamma rays had better penetration than that, my source did not give the all important percentages. I put this forward to find out its estimated impact, and I did. Once I am able to calculate accurately a model of asteroid destruction I do intend to do so *goes off muttering about properties of rock and efficiencies of energy transfere...*

[Major Diarrhia]

Kinda off topic, I was watching voyager today. There was some kind of torpedo/missile thing with artifical intellegence, 7 of 9 said it was some kind of high explosive anti-matter weapon.

Point is , it wasn't any bigger then a standard photon torpedo and the quote was something like this "The blast radius of 200km, radiogenic particles blah blah blah."

Is it possible to assume that a weapon of similar design and size could mean a PT could be as powerful?

I've always belived yield isn't a matter of how much M/AM there is. That torpedoes have a disproportionatly large yield.

[Uraniun235]

I've always belived yield isn't a matter of how much M/AM there is. That torpedoes have a disproportionatly large yield.

Huh? You're saying that photon torpedoes should be weaker than what we see on screen?

[Major Diarrhia]

I've always belived yield isn't a matter of how much M/AM there is. That torpedoes have a disproportionatly large yield.

Huh? You're saying that photon torpedoes should be weaker than what we see on screen?

Not exactly, damage done is damage done. I'm just saying that torpedoes may be doing more with less. Sort of like how a phaser vaporizes stuff but without needing gigatons of energy or at the very least causing the equivilant of a nuclear explosion when the molecules lose their bonds. Then again, it has never been stated on screen how much anti-matter they hold, maybe they compress the stuff into a solid. Personaly I think the damage a torpedo can do is pretty high.

[Kazuaki Shimazaki]

Not exactly, damage done is damage done. I'm just saying that torpedoes may be doing more with less. Sort of like how a phaser vaporizes stuff but without needing gigatons of energy or at the very least causing the equivilant of a nuclear explosion when the molecules lose their bonds. Then again, it has never been stated on screen how much anti-matter they hold, maybe they compress the stuff into a solid. Personaly I think the damage a torpedo can do is pretty high.

Actually, all it takes to do the damage on screen (low megaton range at most IIRC) is less than 1kg worth of matter annihilation. Even if you assume it is of mere water density, 1kg of reactant is 0.001m^3 (that's a cube 10cm across.) At a density of about 10 times that of water (over iron and less than lead,) the cube would have to be 0.0001m^3 (that's a rectangular prism 10cm long and wide, but only 1cm high.)

A phaser does seem to 'borrow' energy from the target, but even then, it's effective yield generally isn't that impressive.