Page 85

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Mjolnir
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Re: Page 85

Post by Mjolnir »

I should also have mentioned that that time and power calculation assumes constant acceleration. In reality, the acceleration will drop as the velocity of the projectile relative to the gun increases, leading to lower exit velocity, or the power required will rise as the projectile accelerates, leading to a peak higher than the average...how much depends on the exact acceleration curve. Particle beams have the benefit of a flatter power consumption over the course of the shot, because they're firing a stream of particles rather than accelerating a single mass.

Again, the main reason I think particle beams may be easier than hypervelocity EM projectile guns is that while a weaponized particle beam would likely fire in a brief pulse, the rise and fall times of the power supply aren't nearly as critical an issue...some particles might be fired at suboptimal velocities, but you don't end up with your one and only projectile already partway down the rails by the time the main pulse hits it, losing acceleration distance, or flying out the end of the gun while you're still trying to put energy into it, wasting input energy. And as you scale up energy and scale down timescales, the problems railguns and such face rapidly become much harder to deal with, while with particle beams...just adding parallel systems will do to increase overall shot power and energy, and that's worst case, scaling up the system will probably work better.

The downside is again operation in atmosphere...particle beams don't penetrate atmosphere very well in the first place, and a compact linear accelerator is a lot harder to build when you have the issue of atmospheric breakdown shorting things out. So without a space battleship to mount weapons on, we're going to see mostly railgun and laser development.

dfacto
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Re: Page 85

Post by dfacto »

Ok, I concede that particle cannons would make good weapons, and probably be much more efficient than a railgun in space.
I don't envision any cyclotron, just a straight linear accelerator...more straightforward to scale up in beam intensity, and it's what existing particle beam milling machines use. And probably with a particle source more like those used in plasma drives in development now, such as VASIMR.
Actually, wouldn't a cyclotron be a much better alternative? If you're not chasing high fractions of c, then the cyclotron lets you have a much smaller gun with the ability to constantly fire rounds by injecting them straight into the middle, rather than requiring pulse fire. You would need a short barrel to refine the particle path after exiting the cyclotron though.

You could use the same energy, have smaller rounds, but maintain a "stream" of fire which would do significant damage at a greater speed.

Also I know everyone talks about lasers being difficult to scale up, but since the 90s when I started reading about military applications they have been scaled up, and quite significantly. I have a feeling laser tech is greatly underestimated by a lot of people. Most likely when we finally decide we need to kill each other in space, we'll be doing it with lasers, and they'll pack a punch.

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Re: Page 85

Post by BattleRaptor »

Actually particle accelerators are EXTREMLY inefficent even if we assume 1:1 return on input energy to output energy at the emitter, particle accelerators capable of dense streams require focusing devices.
Focusing a particle stream takes many times more energy then the actual emitter, the denser the particle stream and the greater the conformation, exponentially greater energy wasted.

Maybe Mjolnir is aware of a self focusing or naturally coherent particle emitter that also lends itself to be launching densely packed streams capable of causing physical damage and still being useful after a few million kilometers, even if its just theory.
Could I get the name of such a device, I would love to read about it.

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Re: Page 85

Post by Mjolnir »

dfacto wrote:Actually, wouldn't a cyclotron be a much better alternative? If you're not chasing high fractions of c, then the cyclotron lets you have a much smaller gun with the ability to constantly fire rounds by injecting them straight into the middle, rather than requiring pulse fire. You would need a short barrel to refine the particle path after exiting the cyclotron though.

You could use the same energy, have smaller rounds, but maintain a "stream" of fire which would do significant damage at a greater speed.
The cyclotron largely lets you achieve a given particle energy in a shorter weapon. I don't think it's notably more efficient. Something similar might be used to separate and inject particles into the linac...and as for continuous fire, I don't think they're any better suited than linacs. I assumed pulsed shots because you still want high powers to inflict damage, and storing it for a bit and releasing it all at once lets you achieve higher peak power levels than you can sustain. Plus, shorter pulses will deliver more energy to a smaller portion of the enemy ship. They might be more efficient than a multi-stage linac, though.

dfacto wrote:Also I know everyone talks about lasers being difficult to scale up, but since the 90s when I started reading about military applications they have been scaled up, and quite significantly. I have a feeling laser tech is greatly underestimated by a lot of people. Most likely when we finally decide we need to kill each other in space, we'll be doing it with lasers, and they'll pack a punch.
Well, there are some useful chemical lasers around now, and arrays of solid state lasers that can operate in the tens of kW range, but for scaling up in power it's always looked like we'd need to go the free electron laser route. As I mentioned before, those are in development now, but a prerequisite for a 1 MW FEL is a >1 MW electron beam (albeit one with a rather closer target). And as far as I know, FELs generally use linacs rather than one of the various types of ring accelerators, though I think some work has been done at "recycling" the beam exiting the end instead of dumping it and its left-over energy as waste heat.

BattleRaptor wrote:Actually particle accelerators are EXTREMLY inefficent even if we assume 1:1 return on input energy to output energy at the emitter, particle accelerators capable of dense streams require focusing devices.
Focusing a particle stream takes many times more energy then the actual emitter, the denser the particle stream and the greater the conformation, exponentially greater energy wasted.
You're going to need to give a cite for that.

The big research accelerators do require very narrow ranges of input particle energies and trajectories and need to keep stray particles away from instrumentation, and so cull the majority of the injected particles, wasting large amounts of power, and in ring accelerators (especially those using non-superconducting magnets), the chains of quadrupole magnets that steer and maintain the beam focus probably consume quite a lot of power relative to that spent accelerating the particles. I'm not aware of any reason focusing would have any significant share of the total power consumption in a short, low-particle-energy linac, though...and it's certainly not the case in the very small end, such as electron guns for CRTs and such. Just the acceleration accomplishes much of the task, the initial tangential velocity becoming small in comparison to the gained forward velocity and easily countered via Lorentz forces.

I'm not sure at all why you're even talking about the emitter...if you mean the particle source, the particles haven't even been accelerated yet, and you're lumping in the rest of the accelerator, which actually puts power into the beam, with focusing of the beam.

BattleRaptor wrote:Maybe Mjolnir is aware of a self focusing or naturally coherent particle emitter that also lends itself to be launching densely packed streams capable of causing physical damage and still being useful after a few million kilometers, even if its just theory.
Could I get the name of such a device, I would love to read about it.
I'm not suggesting anything will be useful in the millions of km range (even Outsider weaponry doesn't have that sort of range), and large-aperture lasers are probably the way to go for extreme range weaponry. Or guided missiles, assuming such can survive whatever defenses are in place.

That said, helicon plasma beams have been suggested for beamed propulsion specifically due to self focusing effects that allow them to be used at relatively long ranges. Look up the MagBeam concept.

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Re: Page 85

Post by BattleRaptor »

Exactly what would I cite? I asked you to provide a Particle emitter or accelerator whatever you would like to call it, thats capable of being efficent as you describe... becuase you are going on and on how railguns are not.. and how Particle Weapons are BETTER in terms of energy consumption.

You may want to look up the Magbeam yourself, coherence hasnt been accheived over any real distance... not even 9ft.
Even if it does work it requires the Spaceship to have a Magneticsail that extends kilometers, it also requires the ship to be preaccelerated.

Even if you wish to ignore all of those, it still doesnt support beams capable of punching though metal.. infact the plasma is FOCUSED by the recieving spaceship.

Its also made up of 2 parts, the particle emitter/accelerator and the magnetic focusing nozzle. Particles are not confined during acceleration only after by a magnetic nozzle.

as for the CRT
The Electron Emitter(correct term btw) in a CRT has to be the WORST example.
When one stops and looks at the input/output energy(less then 1% out), much of the energy ends up going into heat, the electrons dont have a uniform speed, and most of the Electrons are culled by the physical aperture.
So yes it does Technicly use more energy then the Electro-Magnets used to confine and deflect the stream.


However
Do the Electromagnets use more energy then they focus/deflect.
YES


A Particle weapon cannot afford such wastage in heat or cull the particles in such a way, it either has to force them to conform or remove them from the stream non-destructively.This takes energy.. it takes a crapload of energy.

If you attempted to upscale a electron gun into 100MW beam range and attempted to fire your ship would explode.

You decided to get into the argument with a statement I made in this very thread, the argument was based on the assumption I implied that THE SAME RAILGUN that fires pellet with reduced weight would have double the velocity, and you argued because of inefficiencies it wouldnt, you then repeatedly brought up how inefficient RailGuns are in relation to Particle Accelerators.

One could then expect, reasonably I might add, that you apply the same problems with inefficiencies to Particle Accelerators as you have decided to point out with Railguns.

It takes the same ammount energy to accelerate physical mass as it does Particles to the same energy level assuming 100% efficiency.

Maybe you would like to post a spreadsheet listing the power waste of known railgun designs agasint known Particle Accelerator designs that are capable of being upscaled into weapons.

I for one actually LACK such information, but I can say without a doubt your argument about how efficient Particle Accelerators are compared to railguns isnt anywhere as clear cut as you would make it seem.

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Re: Page 85

Post by fredgiblet »

BattleRaptor wrote:You decided to get into the argument with a statement I made in this very thread, the argument was based on the assumption I implied that THE SAME RAILGUN that fires pellet with reduced weight would have double the velocity, and you argued because of inefficiencies it wouldnt
1. You never stated that it would be a vastly different weapon firing the different slug, you said, and I quote "Half the weight double the speed" with no mention of the design of the weapon.
2. It doesn't really make much of a difference anyway.

The problem isn't just inefficiency, it's basic physics. Doubling acceleration while leaving the barrel length the same will get you roughly (IIRC) 1.4 times the muzzle velocity assuming that efficiency stays the same. The end result of that is that to double the velocity you need to increase the barrel length and/or increase the energy. If you do either of those things you are no longer comparing apples to apples, you're comparing this to this with predictable results.

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Re: Page 85

Post by dfacto »

Mjolnir wrote:The cyclotron largely lets you achieve a given particle energy in a shorter weapon. I don't think it's notably more efficient. Something similar might be used to separate and inject particles into the linac...and as for continuous fire, I don't think they're any better suited than linacs. I assumed pulsed shots because you still want high powers to inflict damage, and storing it for a bit and releasing it all at once lets you achieve higher peak power levels than you can sustain. Plus, shorter pulses will deliver more energy to a smaller portion of the enemy ship. They might be more efficient than a multi-stage linac, though.
I don't really see how pulsed power would be of any benefit with a cyclotron. You need oscillating fields between two dees. It's about frequency and power over a longer period of time, not power pulses. As I see it the linac would have:

-pulsed power requiring pulsed shots
-pulsed shots at high power requiring similar capacitor banks as railguns (I assume, not sure about this one)
-pulsed shots requiring larger single rounds (milligrams or grams)
-larger rounds at the same speeds would require far more power

With a cyclotron you could maintain constant power to the dees and inject much smaller quantities of shot (nanograms or less) and fire an effectively constant stream at enemies. Less punch per any given amount of time, but constant damage. And with the space and power saved you could have more gun per ship.
I'm not sure at all why you're even talking about the emitter...if you mean the particle source, the particles haven't even been accelerated yet, and you're lumping in the rest of the accelerator, which actually puts power into the beam, with focusing of the beam.
You couldn't use an emitter for your concept. You'd be hard-pressed to find something that puts out grams of material in any useful span of time. The rounds would have to be premade magnetically contained packets of particles.

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Re: Page 85

Post by osmium »

BattleRaptor wrote:Exactly what would I cite? I asked you to provide a Particle emitter or accelerator whatever you would like to call it, thats capable of being efficent as you describe... becuase you are going on and on how railguns are not.. and how Particle Weapons are BETTER in terms of energy consumption.
1) the ask for a citation is obvious; where are you getting your efficiency numbers? We have a lot of "beam weapon" examples: XRD's, the electron gun in an SEM, particle accelerators, CRT's etc. Each is designed with something other than "weapon" in mind, so where are these numbers coming from. If you're just grabbing an "efficiency" number from a CRT it will be a pointless number as for a weapon we care about energy imparted to the beam, not efficiency of light production.

2) the point is that even if you grant your efficiency argument, with the acceleration the Loroi and Umiak are capable of in outsiders and the known limitations on what railguns / coilguns are likely to be able to do railguns are only useful in very rare situations as a weapon because you CAN'T HIT ANYTHING with them.
BattleRaptor wrote: You may want to look up the Magbeam yourself, coherence hasnt been accheived over any real distance... not even 9ft.
Even if it does work it requires the Spaceship to have a Magneticsail that extends kilometers, it also requires the ship to be preaccelerated.

Even if you wish to ignore all of those, it still doesnt support beams capable of punching though metal.. infact the plasma is FOCUSED by the recieving spaceship.

Its also made up of 2 parts, the particle emitter/accelerator and the magnetic focusing nozzle. Particles are not confined during acceleration only after by a magnetic nozzle.
My reading up on it is quite different. The point of the system is to accelerate a ship, not punch a hole in anything. You just need to scale up the speed and number of particles. The key bit here is that Mjolnir provided an example of exactly what you wanted: a self focusing particle beam. And instead of saying something reasonable like "Oh that's interesting, I wonder (or provide evidence) of why this would/wouldn't work if adjusted for a military application". Instead in your 30 second read through of the wiki (or whatever you skimmed) you missed the forest for the trees as, to my eyes, it appears like you have been doing for this whole thread with every single other person in this thread who has responded to you. Take some time, read it, maybe let it sink in for an hour or something then respond.
BattleRaptor wrote: as for the CRT
The Electron Emitter(correct term btw) in a CRT has to be the WORST example.
When one stops and looks at the input/output energy(less then 1% out), much of the energy ends up going into heat, the electrons dont have a uniform speed, and most of the Electrons are culled by the physical aperture.
So yes it does Technicly use more energy then the Electro-Magnets used to confine and deflect the stream.
So to give you an example written out specifically. This is exactly what Mjolnir asked for.

Give me a source for your CRT energy output efficiency number, where are these losses? Because I think the CRT beat 1% energy efficiency for *light* production, and for a weapon all we care about is accelerated particles, so for a weaponized CRT it would probably beat 10% efficiency. When my back of the envelope, order-of-magnitude type calculations are way out of whack with your statements I question them. Hence the request for your source.
BattleRaptor wrote: However
Do the Electromagnets use more energy then they focus/deflect.
YES
I fail to see why applying force perpendicular to the acceleration in order to maintain cohesion is going to be such a huge percentage of energy expenditure.
BattleRaptor wrote: A Particle weapon cannot afford such wastage in heat or cull the particles in such a way, it either has to force them to conform or remove them from the stream non-destructively.This takes energy.. it takes a crapload of energy.
other simpler case which is probably used: make sure stray particles just don't impact your equipment with too much force. You don't *have* to "force" them to conform (although I, as above, take issue with containment being such a huge issue, this isn't a tokamak and it's not a cylotron where you need to curve the beam...if this really were such a huge issue there wouldn't be devices like SEM's, focused beam ion mill because you wouldn't be able to control the beam of electrons / particles)
BattleRaptor wrote: If you attempted to upscale a electron gun into 100MW beam range and attempted to fire your ship would explode.
A wonderful statement, but likely wrong and quite hyperbolic. You might melt something, but explode? To note here it might be nice to provide some additional reasons, your thoughts / musings etc. Because at face value this argument is "because I said so" which you'll find rarely flies here.
BattleRaptor wrote: You decided to get into the argument with a statement I made in this very thread, the argument was based on the assumption I implied that THE SAME RAILGUN that fires pellet with reduced weight would have double the velocity, and you argued because of inefficiencies it wouldnt, you then repeatedly brought up how inefficient RailGuns are in relation to Particle Accelerators.
At best you "implied" that you meant different guns(i.e. didn't specify). Hence the confusion. When, say, 3 or 4 different people obviously did not catch what you meant, specify it. Don't get your panties in a wad over some slight to your intellect or something. "Oops that was a midnight post, sorry, I meant to take the conversation down the path of 'why design for larger rounds?'" And it would be over no flame war required.

to answer my own question: one reason might be time to target. If the bigger round is still reliably hitting the targets it is designed for, it's easier to accelerate the round slower over a longer period to attain the same energy output. The only reason reason for a lighter round is if you can't reliably hit targets. This essentially will change based one 1) max energy output which limits reasonably the max velocity for a given round mass and 2) the acceleration of ships. You will find that at some range the efficiency drop off is not worth the increased accuracy and it's better to just put in 2 mass drivers and launch 2 rounds (or maybe do 2 rounds in a row), this range will be dependent on the acceleration ships can reliably maintain over the combat time frame... otherwise your argument is actually an argument for particle weapons (or something like it).

As you've essentially set up what is similar to xeno's paradox. If you have picked arbitrarily 1/2 the mass and 2x the velocity (same energy) why not 1/16 the mass and 4x the velocity better? why isn't 1/256th the mass and 16x even better? Would that not have even better range and speed and weapon properties? The only limit to this argument is the smallest mass of a particle or the speed of light, whichever you hit first.
BattleRaptor wrote: One could then expect, reasonably I might add, that you apply the same problems with inefficiencies to Particle Accelerators as you have decided to point out with Railguns.
I actually do not think it's very reasonable, they are very very different creatures. Friction and not destroying the projectile by trying to accelerate it are big problems for a railgun that don't exist at all for a particle accelerator. Now it might turn out that upon analysis they are similar enough, as they both use electromagnetism to accelerate their projectiles, the how is slightly different though. Out of hand, I think it's risky to fire from the hip and make a sweeping statement like that.

-O

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Re: Page 85

Post by Mjolnir »

dfacto wrote:I don't really see how pulsed power would be of any benefit with a cyclotron. You need oscillating fields between two dees. It's about frequency and power over a longer period of time, not power pulses. As I see it the linac would have:
Yes, but you've got an oscillator driving the cavity. I wasn't referring to a brief, violent pulse as with a railgun, but of firing the weapon at a low duty cycle at a higher power than you can sustain continuously.

dfacto wrote:With a cyclotron you could maintain constant power to the dees and inject much smaller quantities of shot (nanograms or less) and fire an effectively constant stream at enemies. Less punch per any given amount of time, but constant damage. And with the space and power saved you could have more gun per ship.
The less punch for any given time is the one and only reason why I was assuming pulses. It has nothing to do with linear accelerators, it applies just as well with lasers. As for saving space and power, scaling a cyclotron up to the beam current needed would be far more difficult...think of all the charged particles in there at any given time, circulating and deforming the electromagnetic field inside with their own fields.

dfacto wrote:You couldn't use an emitter for your concept. You'd be hard-pressed to find something that puts out grams of material in any useful span of time. The rounds would have to be premade magnetically contained packets of particles.
Hah, and then there's the issue of dealing with grams of decay particles produced when you're not firing, and the enormous quantities you'd have to carry to have any around. I'd assumed (maybe wrongly, given the quality of his responses) that he couldn't possibly be talking about a decay emitter, but was talking about any particle source. And he did get around to mentioning the cathode of an electron gun, though indirectly, and he seems to think the emitter does all the acceleration for some reason.

There's no particular need for a quadrupole magnet (used for magnetic beam steering and focusing) to consume any power. It doesn't do any work (in the physics sense), it just sits there as particles go through its field. Similar goes for electrostatic focusing and deflection. Most accelerators use non-superconducting magnets, though, so power consumption is quite high whether a beam is being focused or not, and maintaining superconducting systems itself costs large amounts of power here on Earth, and with a short linear accelerator we don't care nearly as much about bunching the particles into clean packets, so I suspect BattleRaptor's mysterious power drain in beam focusing is just completely inapplicable.

As for the particle beam being the extreme in scaling velocity up and mass down, that's apples and oranges. A particle beam weapon doesn't have to deliver all of a shot's energy in the time it takes a single particle to traverse the weapon, and it doesn't have to accelerate its payload using a magnetic field induced by driving currents through said payload. As osmium noted, I made the arguments I did because we were talking about a completely different weapon.

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Re: Page 85

Post by icekatze »

hi hi

Suppose you made a rail gun where the round is longer than the barrel? It could be a spike 2 kilometers long, then you could gradually impart energy as it passes along the rails.

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Re: Page 85

Post by Mjolnir »

icekatze wrote:Suppose you made a rail gun where the round is longer than the barrel? It could be a spike 2 kilometers long, then you could gradually impart energy as it passes along the rails.
You've then got reduced acceleration due to the higher projectile mass, and the projectile itself has to deal with some extreme compression and tension forces during firing. And there's the little mechanical issues of storing and handling those long projectiles. You'd be better off firing a stream of small separate projectiles...which may in fact work. It'd be limited by heating of the rails, but resistive losses are proportional to the square of current, so firing a stream of smaller projectiles using smaller currents might reduce losses and heating for the same total output shot energy.

You wouldn't be able to optimize the pulse shape for each projectile when you have multiple projectiles on the rails...that'd be easier to do with smaller, lower energy projectiles, but requires that only one be on the rails at a time. This may lead to a significant loss in efficiency...fine tuning of such things can make a big difference in the output in devices like railguns. Look at the Sandia Z accelerator experiments, where careful tuning of the discharge over time together with tweaks of the projectile construction let them get from ~16 km/s to 45 km/s. The reduced energy per projectile still helps even if they're fired as separate shots, though, if you can come up with a way to repeat firing rapidly enough that the projectiles of a burst have a good chance of hitting the same part of a target.

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Re: Page 85

Post by Ktrain »

This overly in depth digression has inspired me to register.
icekatze raise are great question about the function of large scale mass drivers, since humanity (both current and fictional) has never been involved in actual space combat, large scale mass drivers should be viewed as an attempt to prepare for such combat. Before WWI, Battleships' main armaments consisted mainly of small scale guns (6") while after actual combat it was shown that fewer large velocity guns were preferable. The discussion concerning mass drivers and particle/laser weapons should be viewed in this context.

Maybe would should accept that future human have overcome the current limitations associated with mass drivers and that there are trade offs between speed and accuracy. Minutia be damned :)


PS: Can't wait till the next page for new (less flamed) discussions.
OUTSIDER UPDATE => HALF LIFE 3 CONFIRMED?

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Re: Page 85

Post by BattleRaptor »

fredgiblet wrote:
BattleRaptor wrote:You decided to get into the argument with a statement I made in this very thread, the argument was based on the assumption I implied that THE SAME RAILGUN that fires pellet with reduced weight would have double the velocity, and you argued because of inefficiencies it wouldnt
1. You never stated that it would be a vastly different weapon firing the different slug, you said, and I quote "Half the weight double the speed" with no mention of the design of the weapon.
2. It doesn't really make much of a difference anyway.

The problem isn't just inefficiency, it's basic physics. Doubling acceleration while leaving the barrel length the same will get you roughly (IIRC) 1.4 times the muzzle velocity assuming that efficiency stays the same. The end result of that is that to double the velocity you need to increase the barrel length and/or increase the energy. If you do either of those things you are no longer comparing apples to apples, you're comparing this to this with predictable results.
Not what I said at all, unless you think cutting up sentences is acceptable.

1.I never said it wasnt, smarty pants.
Weapons however when they change what they fire also need to change, its common sense.

2.If I HALVE a cake, it is half of the original cake.

If a cake is half the size, it is HALF the size of the original not unless specificly mentioned is it part of the orginal.

See the meaning change between half and halve.
Its very important.
sad thing is, my english is horrible.

I also made the mistake of assuming some things would be apparent... which amazingly they were in that you decided to argue how apparent they were and that my statement was wrong based n the assumption that I didnt and thought something I didnt.

If I was not talking about the original Projectile then I wouldnt be talking about the original gun, it wouldnt function, just like almost projectile weapons known to man.
If you change the size of the round, you have to made modifications to the gun.. or use a diffrent weapon.

Common sense I made the mistake of thinking everyone had.

osmium
Your reading must be very poor.
Its Self foccusing abilities currently leave it at diffusing below 9ft.
The plasma has a very low speed, I think its around 120km/s before its no longer self foccusing.
It also has a maxium density before it also tears itself apart.

This is theory mind you.. since they havnt even got it to say Focused for 9ft in testing.

Its also a Example of a Plasma/particle hybrid.
That has very slow maxium possible therorectical speeds.
Has Diffusion greater then modern lasers even if it works in theory, that excludes its use as a particle weapon unless the targeted ship is going to be nice and focus that plasma itself and blow itself up.

I asked for a example in theory or practice that could be upscaled to be a weapon.
MAGBEAM is not.
Also make up your mind.. is it a example of a weapon as I asked for.. or is it not?

Mjolnir is the one that brought up efficiency, and started spouting about Particle weapons being so much better in this regard.
So why should I have to provide citations for such things and he not?

He brought up CRT NOT I, I simply pointed out they are massively inefficent.
So your back of the Envelope calculations dont support it?
What would those be?

Mine
I decided to start with REAL world examples.
37inch CRT old style TV uses 320watts(dimmer then most LCD, but doesnt use any kind of CPU controler to draw extra voltage, that said moden CRT are far more efficent but they switched from the standard CRT to a hybrid)

a 37inch LCD using a CCFL(9% viable light efficiency) uses ~180 watt.(found between 140-190)
LED LCD(20-40% efficiency) 37inch (60 watts, however not as bright as the normal LCD or CRT)

Unlike a CRT the beam is not split up where only the targeted pixel receives the beam and each beam strength(brightness) is controlled the Light falls across the whole LCD panel.

LCD if assumed to be 100% efficient and all pixels are set to max brightness blocks 66% of the total light that hits the rear of the LCD film.

This discounts the fact LCD blocking light even in the spectrum they are supposed to allow it to pass though, and that about 5% of the screen is cell walls that allow no light though, and is ignored in estimation that the LOSS here is about the same as loss of Electrons to similar effects in a CRT. This is ontop of the loss of light from a non 100% reflective surface, and that some of the light hits non reflective parts of the insides of the LCD screen which is most often black, and even escapes entirely.

This gives a LCD screen 3% BEST CASE energy/output to light, that uses less power then the CRT screen of the same size(we also know that for quite a few years LCD screens have been brighter then CRT).

We know that the CRT is using 50% more power so it must only be half as efficent.. 1.5%.

Assuming same brightness which is yet again another averageing that favours the CRT.

Except for the last factor, around 15-30W of a LCD screen it drawn by its electronics such as the CPU.

So non hybrid CRT at (<=)1% is a reasonable conclusion.

As for Electron Microscopes, they have seen over a 3 fold order of magnitude increase in efficiency since the first generation.
They are also a VERY poor examples, efficiency ratings are combined of the Emitter and the receiver, and untill recent methods would make it unfair to even bring them up with rateing in the 0.01% or even less range, now in theory they can get 80% efficiency yet the method is for single atom electron emitters, cant be used for a weapon due to interference between emitters.

osmium wrote:A wonderful statement, but likely wrong and quite hyperbolic. You might melt something, but explode? To note here it might be nice to provide some additional reasons, your thoughts / musings etc. Because at face value this argument is "because I said so" which you'll find rarely flies here.
a 100MW beam based on a Electron Emitter from a CRT design would require 10000MW of energy being transfered almost instantly into a Physical blocking aperture, I did state CRT at less then 1%.
Ship goes BOOM, I thought such things would be as apparent to others as they are to me, my mistake, I apoligise.



Lasty now... the argument has turned into.

The Particle beam doesnt need to acclerate all the particles to the same speed?.
It doesnt matter...

Lets assume a particle beam with a average DIFFRENCE in acceleration of its particles of 10% and of max speed 99% light.
Lets assume at point blank range the particle weapon JUST penetrates with a single shot enemy armor.
Lets also pretend the particle beam isnt a beam but actually a Discreate PELLET and that all particles are fired INSTANTLY.
Lets take Loroi vessal acceleration of 30g as a base for this example.

At one light second such a pellet has now expanded to ~30000 kilometers in length and now takes 0.1 second to fully hit a target.
A Ship at 147m/s relative velocity can move during that .1 of a second 14.7 meters during start to finish of getting hit with the beam.

beams effectiveness now now been droped to ~1/15th of its effective power.
If at point blank range the particles could just penetrate the armor of the ship, it now takes 14.7 shots on the EXACT same location to penetrate.

Now a SHIP would be traveling FAR faster then this... lets take a ship that has undergone 5 seconds of acceleration at 30g.
Its Velocity is 1470m/s.

in 1/10th of a second it Travels 147 meters.

Its now going to take 147 shots of that same particle weapon to penetrate the ships armor assuming it swiped the ship exactly the same spot every time.

Which brings us back to RELATIVE speed.

So far we have only countered ONE ship, but there are infact 2, this means the Relative velocity assuming they both perform equaly could be zero... to 2930m/s.
Which even assuming a beam hits a ship the entire team, the beams effective penetration power can be as low as 1/294th.

Yet in reality it would do even far less damage.
A perfect real world example, armor penetrators.. just a 20% drop in energy can cause them to go from penetrating the target to causing no damage.
I have been extremly generous towards particle weapons in assuming energy/surface area is the only cause of drop in effectiveness.

Particle weapons to actually be effective they need to either fire Particles as descrete packets at the same Relative velocity.

OR

They need to be a continued Beam Operation, which would require such large ammounts of power and mass as to be well.. massively INEFFICENT at anything but short range.
We know this is not the case because we know the destructive energy levels of the outsider beam weapons, we also know there effective range.
A Particle Beam in outsiders that fired over 1 second would be useless agasint a moving dodging target at one light second.

This all comes in before we take into account normal diffusion, over a light second the stream could be 2-3 maybe even 10 times wider, nothing we have today can accheive this.. or even GET in the order of magnitude of it.
Which once again effects how efficient the weapon is, if you are spreading your energy across an area 1/1000th or even GREATER(diffusion+time+speed) what was once a weapon capable of blowing a ship apart at point blank range now is simply recorded on the targeted ship as slight increase in hull temperature.

If weapon focus only tripples at 1 light second, and particle speeds only have a 0.1% variation, Loroi ships with a 20-30second acceleration would become damn near immune to there own particle weapons.
Infact the greatest defense agasint particle weapons of this kind wouldnt be armor or shields but speed.

When we add in the shields that Both Loroi and Umiak ships have.
Fighting with particle weapons that dont fire single homogeneous packets at anything other then point blank ranges(mass driver range) is impossible for the given destructive energy levels given in outsider to cause any reasonble damage to a moving ship.

Nemo
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Re: Page 85

Post by Nemo »

BattleRaptor wrote:1.I never said it wasnt, smarty pants.
Weapons however when they change what they fire also need to change, its common sense.

Ok. Just.... stop. At a certain point I have to assume youre fighting for its own sake. You were wrong. You can not half the weight double the speed and still have double the energy. Own up to it and move on, moving the goal posts and squirming around just makes you look worse.

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Siber
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Re: Page 85

Post by Siber »

A question: You seem to be assuming that the weapon velocity is .1 c and your using it at 1 light second. Why? Engagement ranges are what they are in Outsider because any farther and you don't have any reasonable expectation of a hit. For a .1c weapon I'd think you'd only be using it inside .2 ls.

An observation: I think why people came at you for the half weight/double speed argument is that accelerating projectiles to higher speeds doesn't have a linear difficulty. Having the technical capability of accelerating a slug of mass x to velocity y does not imply the capability of accelerating a slug of mass x/2 to a velocity of 2y, and if the first weapon is at the limits of their ability then it implies rather that the second weapon is outside of their capability. Going smaller and faster may still be productive, you can hit at longer ranges and you can carry more rounds, but you won't hit as hard.
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NOMAD
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Re: Page 85

Post by NOMAD »

Battleraptor, you may might also want to consider the engineering changes that must be made to a weapon with double the "Speed" as you imply, just because the simply formals used here show, theoretically show that it could be possible ( and as Mjolnir as proven, can't without a major increase in power).

now say, if we were able to increase the speed of a KE gauss round to X2 using a normal X1 speed weapon. now true you got the power needed for the increase and changes the bore of the barrel to fit the smaller projectile. You have to change the the following, shock/damping system, power feed/supply, mounting bracket ( reinforcements to take the increase recoil, heavier mags need etcs). The basics of my point is that you have to change alot of factors in order to get a weapon to work properly (and effectively).

This same problem was encountered by both axis and allied sides in the tank development. the problem was ( and the British in particular found this out) was the you could necessarily put in a bigger tank gun into their current tanks, just to cope with the Germany Panzer's having thicker armour. They couldn't and often they need to change the turret ring diameter (for a bigger turret to accommodate the large gun), the gun mount need to be stronger ( recoil and larger angle improvements IE better shooting performance). these changes often meant redesigning the some or often the whole tank in these chase.

Note: in anythign doesn't make sence please let me know.

battle, I know you made your point, I respect your "fortitude" in stinking with your theory but Nemo does have a point. could we move on to the next subject ?
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fredgiblet
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Re: Page 85

Post by fredgiblet »

BattleRaptor wrote:1.I never said it wasnt, smarty pants.
Weapons however when they change what they fire also need to change, its common sense.
Of course, you know what else is common sense? That if you don't specifically state that a weapon will have a significantly different design that the aforementioned changes will be minimal. Obviously the railgun would need to be modified to support a different projectile, but the assumption that we should assume that you are talking about a weapon with the VASTLY different design required to make your statement true is unreasonable.
2.If I HALVE a cake, it is half of the original cake.

If a cake is half the size, it is HALF the size of the original not unless specificly mentioned is it part of the orginal.

See the meaning change between half and halve.
Its very important.
Huh?

I also made the mistake of assuming some things would be apparent... which amazingly they were in that you decided to argue how apparent they were and that my statement was wrong based n the assumption that I didnt and thought something I didnt.

If I was not talking about the original Projectile then I wouldnt be talking about the original gun, it wouldnt function, just like almost projectile weapons known to man.
If you change the size of the round, you have to made modifications to the gun.. or use a diffrent weapon.

Common sense I made the mistake of thinking everyone had.
That the design of the weapon would need to be vastly different is quite obvious, however the casual nature of your original post implies that you think such a switch would be simple, you tighten down the bore on the 200kg mass driver, roll the 100kg slug in and bam, double the velocity. The setup that you are NOW claiming would require MUCH greater energy input and/or (probably and) a notably longer barrel, meaning that such a switch is not nearly as simple as your original post implied. Instead of tightening down the bore and turning the power dial up to 11 you are talking about an entirely new weapon with vastly greater engineering requirements which can easily be beyond the technology available to humans as of Outsider. Additionally, even if the technology exists to produce the weapons you are talking about they will still be significantly more expensive than their counterparts meaning that the cost:benefit ratio simply isn't likely to be there.

ETA: It seems that you are on the right side of physics, just on the wrong side of engineering (and communication).

discord
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Re: Page 85

Post by discord »

battleraptor: just want to point out, the CRT/LCD arguments you are a putting forward are about generating VISIBLE LIGHT! at which point you are probably pretty close, but how much energy do you think is lost in the CRT when converting from the particle stream through the screen to produce visible light? as you might know older CRT screens have been known to give sunburn despite being quite 'dim'.

so, the efficiency of the Cathode Ray Tube emitter is NOT the same as the efficiency of a CRT monitor....although i am not sure if that exact technology would scale well, but there are few other ways of producing particle streams, one of them should work.

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Mjolnir
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Re: Page 85

Post by Mjolnir »

discord wrote:battleraptor: just want to point out, the CRT/LCD arguments you are a putting forward are about generating VISIBLE LIGHT! at which point you are probably pretty close, but how much energy do you think is lost in the CRT when converting from the particle stream through the screen to produce visible light? as you might know older CRT screens have been known to give sunburn despite being quite 'dim'.
That argument was so utterly disjointed from reality I didn't know where to start. Using the relative visual brightness of LCD and CRT monitors to judge the efficiency at focusing a particle beam?

discord wrote:so, the efficiency of the Cathode Ray Tube emitter is NOT the same as the efficiency of a CRT monitor....although i am not sure if that exact technology would scale well, but there are few other ways of producing particle streams, one of them should work.
The "emitter" in a CRT is a heated cathode coated with alkali metal oxides that reduce its work function, which takes a few watts of power even when not emitting electrons and produces electrons with thermal energy...a few eV each. The focusing is a series of control electrodes that draw that stream out and, yes, cull some from the edges, providing a directional beam (together with the cathode making up the electron gun) and handling tiny currents at low voltages (meaning they consume little power...this is also why BattleRaptor's claim of exploding ships is unrealistic, he doesn't seem to know the difference between the particle source and the accelerator that actually puts energy into the particles, and has resisted correction on this), the accelerator is the big potential difference between the gun and front of the screen, charged up by the flyback circuit. This involves a small current at a high voltage (tens of kV), and essentially all the power consumed goes into accelerating electrons.

That gets you a spot on the screen. Display CRTs also have the yoke coils, copper windings that are driven with 50-60 Hz and 30-kHz range ramp waves at higher currents than anything else in the CRT...these coils and their drivers alone probably consume more power than the actual CRT. The flyback in typical sets was a cheap and simple way of producing high voltage, not an efficient one, so more power consumption there. When I mentioned CRTs, I was talking about the beam forming, focusing, and acceleration mechanisms of the CRT itself, not CRT monitors as light-producing devices.

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Rosen_Ritter_1
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Re: Page 85

Post by Rosen_Ritter_1 »

shouldn't this go in another thread?

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