10e@hpcvia.hp.com (Steven_Tenney) (10/12/89)
From: 10e@hpcvia.hp.com (Steven_Tenney) A few months ago I read a short blurb on the feasability of using particle-beam technology as a form of future fire power. A particle beam gun would shoot proton energy pellets. Has anyone heard of this possibility? Thanks ahead of time for any available info. Steve Tenney
brown@ncratl.Atlanta.NCR.COM (Kyle Brown) (10/13/89)
From: brown@ncratl.Atlanta.NCR.COM (Kyle Brown) In article <10149@cbnews.ATT.COM>, 10e@hpcvia.hp.com (Steven_Tenney) writes: > > > From: 10e@hpcvia.hp.com (Steven_Tenney) > > A few months ago I read a short blurb on the feasability of using > particle-beam technology as a form of future fire power. A particle > beam gun would shoot proton energy pellets. Has anyone heard of this > possibility? > > Steve Tenney There are some *major* problems with using particle beams as weapons. Not the least of which is that the power required to make a particle beam do anything interesting (say cut through armor more than paper thin) is in the megawatt range. Also, Proton beams are the only candidates for such weapons, and these are *not* easy to generate or play with (any plasma physicists out there want to elaborate?) This topic will have to stay in rec.arts.sf-lovers for a couple o' decades ------------------------------------------------------------------------ "Earth: Mostly Harmless." -- The Hitchiker's Guide to the Galaxy brown@ncratl.atlanta.ncr.com
budden@manta.nosc.mil (Rex A. Buddenberg) (10/14/89)
From: budden@manta.nosc.mil (Rex A. Buddenberg) There are occasional references to particle beam weapons in open literature. Naval Institute Proceedings has notes on the subject occasionally. It's obvious that we're not hearing the whole story. A couple issues ago, there were some notes about the next generation of Navy ships and there is an interesting wrinkle in the logic. Most of the verbiage referred to the process of defining the problem. The disconnect is that one <solution> has crept in -- electric main propulsion. But the benefits apparently make it an attractive enough concept to build around: - electric power, particularly in an era where high temp superconductors appear to be becoming a practical technology, allows great flexibility in machinery plant arrangements. Wonderful news to naval engineers who can benefit by having some of their design constraints go away. And shaft alignments are real problems when they come as battle damage... - ability to diver this large bagful of kilowatts to an electrically driven weapon for short periods of time. Particle beam weapons, lasers and related technologies will require large amounts of power and the ability to dual-use what you've already put there as propulsion power is a further economy. Now, unless the Navy has some black program out there, this isn't likely to happen for a few years. The DDG-51 class of destroyer is gas turbine propelled and has a weapons suite that looks fairly familiar. And lead ship is at the christening stage about now. So it'll be a few years before the Navy gets to the next break point in construction where something like this might be programmed for production. All from memory... Rex Buddenberg
cerebus@bucsf.bu.edu (Tim Miller) (10/14/89)
From: cerebus@bucsf.bu.edu (Tim Miller) On 12 Oct 89 03:19:03 GMT, 10e@hpcvia.hp.com (Steven_Tenney) said: ST> A few months ago I read a short blurb on the feasability of using ST> particle-beam technology as a form of future fire power. A particle ST> beam gun would shoot proton energy pellets. Has anyone heard of this ST> possibility? I've heard nothing on this; I'd like to know if you can provide a short summary of the article (e-mail). The thing that bothers me about the feasibility of battlefield man-killing lasers or particle beams is one of power consumption. They suck power like MAD. The problem also is linked to the fact that a laser or particle beam hooked up to an inferior power source is of ZERO effectiveness rather than reduced effectiveness; read that as useless without an ideal power source operating perfectly in the field (and everything fails sooner or later, though usually sooner). I rather like the idea brought up by some military s-f writers: rather than a laser or other beam weapons, what about a small pellet moving at .7c or some such insane velocity. They call this type of weapon a 'relativistic BB-gun.' Comments? Timothy J. Miller cerebus@bucsf.bu.edu
jwtlai@violet.waterloo.edu (Jim W Lai) (10/14/89)
From: jwtlai@violet.waterloo.edu (Jim W Lai) In article <10184@cbnews.ATT.COM> brown@ncratl.Atlanta.NCR.COM (Kyle Brown) writes: >There are some *major* problems with using particle beams as weapons. >Not the least of which is that the power required to make a particle beam >do anything interesting (say cut through armor more than paper thin) is >in the megawatt range. Also, Proton beams are the only candidates for such >weapons, and these are *not* easy to generate or play with (any plasma >physicists out there want to elaborate?) With respect to SDI, the APS directed-energy weapons study considered only neutral particle beams. They mentioned that neutral-particle beams are rapidly ionized once they enter the thin upper atmosphere at 100 km, and are then rapidly deflected by the Earth's magnetic field. For terrestrial use, we can rule out neutral particle beams, since they won't be neutral for very long at ground level. They power requirements they considered of practical use for killing missiles were between 100 MW and 1000 MW, depending on range and retargeting rate. Considering this, IMHO the problem of scaling down and modifying such technology for use by, presumably, armored vehicles is nontrivial (i.e. difficult). I would expect the crew would have to be shielded against the magnetic forces used to accelerate the ions. I don't know enough to estimate the range of a beam of positive ions in air. How much power does a tank engine produce?
dave@sun.soe.clarkson.edu (Dave Goldblatt) (10/16/89)
From: Dave Goldblatt <dave@sun.soe.clarkson.edu> In article <10184@cbnews.ATT.COM> brown@ncratl.Atlanta.NCR.COM (Kyle Brown) writes: >There are some *major* problems with using particle beams as weapons. >Not the least of which is that the power required to make a particle beam >do anything interesting (say cut through armor more than paper thin) is >in the megawatt range. Also, Proton beams are the only candidates for such >weapons, and these are *not* easy to generate or play with (any plasma >physicists out there want to elaborate?) Well, when I was working on such an (unclassified) project a few years ago, the idea was not necessarily to cut through missiles (for example), but to destroy the electronics inside by exposure to the particle radiation. This would not require anywhere near as much power as actually slicing up the target would. I understand that this is currently a feasible SDI project now. >This topic will have to stay in rec.arts.sf-lovers for a couple o' decades Well, at least a few more years. :-) >------------------------------------------------------------------------ >"Earth: Mostly Harmless." -- The Hitchiker's Guide to the Galaxy >brown@ncratl.atlanta.ncr.com -dg- (Save the F-14D Super Tomcat!) -- Internet: dave@sun.soe.clarkson.edu or: dave@clutx.clarkson.edu BITNET: dave@CLUTX.Bitnet uucp: {rpics, gould}!clutx!dave Matrix: Dave Goldblatt @ 1:260/360 ICBM: 75 02 00W 44 38 12N
djm@castle.ed.ac.uk (D Murphy) (10/16/89)
From: D Murphy <djm@castle.ed.ac.uk> In article <10233@cbnews.ATT.COM> cerebus@bucsf.bu.edu (Tim Miller) writes: > > >From: cerebus@bucsf.bu.edu (Tim Miller) > > >On 12 Oct 89 03:19:03 GMT, >10e@hpcvia.hp.com (Steven_Tenney) said: > >ST> A few months ago I read a short blurb on the feasability of using >ST> particle-beam technology as a form of future fire power. A particle >ST> beam gun would shoot proton energy pellets. Has anyone heard of this >ST> possibility? I really seriously doubt this. Not only do you have the problem of (see below) energy supplies, you're also trying to shoot a very small, highly charged particle through lots of big, neutral particles. No way - consider that beta-emissions are completely stopped by a few feet of air, even the very high energy ones. Protons wouldn't get very far. > > The thing that bothers me about the feasibility of battlefield >man-killing lasers or particle beams is one of power consumption. They >suck power like MAD. The problem also is linked to the fact that a laser >or particle beam hooked up to an inferior power source is of ZERO >effectiveness rather than reduced effectiveness; read that as useless >without an ideal power source operating perfectly in the field (and >everything fails sooner or later, though usually sooner). > Not only this, but even in vacuum there are feasability problems. On an article (a while ago, so I forget where) it was pointed out that charged- particle beam weapons were rejected for SDI because of the targetting difficulties associated with interference of the earth's magnetic field on the particles (you know how an electric motor works ?). Funny - IMHO that'd be obvious. > I rather like the idea brought up by some military s-f writers: >rather than a laser or other beam weapons, what about a small pellet moving >at .7c or some such insane velocity. They call this type of weapon a >'relativistic BB-gun.' > > Comments? > No chance - not in atmosphere. Maybe the Pentagon are wanting to go huntin' and shootin' bug eyed monsters now that the SU are supposed to be nice guys, but again there is the problem of firing in air. The pellet would have to be really small to be launched at such a speed from a weapon of usable size. Trouble is, air resistance goes up with velocity, so the more energy you put into the projectile, the less efficient it gets. > Timothy J. Miller > cerebus@bucsf.bu.edu IMHO, about the only offensive use of lasers (by offensive I mean not used for target designation and homing) is in blinding the opposition's optical targetting systems - anything from laser homing missiles to eyes. I saw an article (I think in the London Financial Times, or maybe the Economist) about just such a device being developed by the SU. Is this true ? Murff...
gwh%earthquake.Berkeley.EDU@ucbvax.Berkeley.EDU (George William Herbert) (10/18/89)
From: gwh%earthquake.Berkeley.EDU@ucbvax.Berkeley.EDU (George William Herbert) In article <10232@cbnews.ATT.COM> budden@manta.nosc.mil (Rex A. Buddenberg) writes: >A couple issues ago, there were some notes about the next generation >of Navy ships and there is an interesting wrinkle in the logic. >Most of the verbiage referred to the process of defining the problem. >The disconnect is that one <solution> has crept in -- electric main >propulsion. >Now, unless the Navy has some black program out there, this isn't >likely to happen for a few years. The DDG-51 class of destroyer >is gas turbine propelled and has a weapons suite that looks fairly >familiar. And lead ship is at the christening stage about now. >So it'll be a few years before the Navy gets to the next break >point in construction where something like this might be programmed >for production. This is true. The navy has had the ability to use electric-coupled powerplants (and has had some) for years. They do have problems, but acceptable ones, and there has been quite a bit of thought on the idea of using this setup for standby power for directed energy weapons. Perhaps the mid-class Arleigh Burke update? **************************************** George William Herbert UCB Naval Architecture Dpt. (my god, even on schedule!) maniac@garnet.berkeley.edu gwh@ocf.berkeley.edu ----------------------------------------
tony@nexus.yorku.ca (Tony Wallis) (10/18/89)
From: tony@nexus.yorku.ca (Tony Wallis) cerebus@bucsf.bu.edu (Tim Miller) : | I rather like the idea brought up by some military s-f writers: rather | than a laser or other beam weapons, what about a small pellet moving at | .7c or some such insane velocity. They call this type of weapon a | 'relativistic BB-gun.' | Comments? - Timothy J. Miller Not in the atmosphere. The pellet would be vaporized by Mach-1000000 heating before it reached the target. (Or the muzzle of the gun !)
MLFISHER@ohstpy.mps.ohio-state.edu (10/18/89)
From: MLFISHER@ohstpy.mps.ohio-state.edu
:> I rather like the idea brought up by some military s-f writers:
:>rather than a laser or other beam weapons, what about a small pellet moving
:>at .7c or some such insane velocity. They call this type of weapon a
:>'relativistic BB-gun.'
:>
: No chance - not in atmosphere. Maybe the Pentagon are wanting to go
: huntin' and shootin' bug eyed monsters now that the SU are supposed to be
: nice guys, but again there is the problem of firing in air. The pellet would
: have to be really small to be launched at such a speed from a weapon
: of usable size. Trouble is, air resistance goes up with velocity, so the
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Actually the viscous force (e.g. air resistance on a projectile) is
proportional to the velocity squared. Even more of a problem.slouie@uts.amdahl.com (Shelley Louie) (10/20/89)
From: slouie@uts.amdahl.com (Shelley Louie) Even before the problems of development of particle beam weapons and/or kinetic motion weapons (ie. Gauss guns), there is the problem of its impracticalities in terms of being a line-of-sight weapon. The Navy's empathsis on missles would still exist even if a cheap energy weapon were developed today. I would contend however that such a weapon would be ideal for use in an anti-air capacity if it were able to fire fast enough. The ability to rapidly fire a accurate series of small shots over a line-of sight difference would make a fantastic middle-range point defense and play havoc in an anti-aircraft situation. As for orbiting sattilites to be used as ultra-high level bombers, the needed mass and accuracy would make such a weapon impractical except vs a clustered target such as a town. Smaller individual targets would be next to impossible to hit on a steady basis. Too many variables to contend with. -shelley
tcmaint%tekigm2.men.tek.com@RELAY.CS.NET (Thomas A. Dowe) (10/24/89)
From: "Thomas A. Dowe" <tcmaint%tekigm2.men.tek.com@RELAY.CS.NET> In article <10412@cbnews.ATT.COM> slouie@uts.amdahl.com (Shelley Louie) writes: >Even before the problems of development of particle beam weapons and/or >kinetic motion weapons (ie. Gauss guns), there is the problem of its >impracticalities in terms of being a line-of-sight weapon. In defense, laser weapons could be extremely effective in certain config- urations. Mechanically manipulated, they could saturate the defensive front with millions of strikes per minute; blinding temporarily, if not permanently, attacking troops. Night vision devices could be rendered ineffective and laser sighting confused. Tad tomd@pulsar.telcom.tek.com
willner@cfa.harvard.edu (Steve Willner) (10/26/89)
From: willner@cfa.harvard.edu (Steve Willner) >> : of usable size. Trouble is, air resistance goes up with velocity, so the > Actually the viscous force (e.g. air resistance on a projectile) is > proportional to the velocity squared. Even more of a problem. Drag forces are confusing, and neither statement is entirely right. The drag force depends on two dimensionless numbers, the Reynolds number and the Mach number. The latter is fairly familiar and is just the ratio of object speed to sound speed. The former may be unfamiliar: it is essentially the ratio of "impact drag" to "viscous drag." In practical weapons and most vehicles, the Reynolds number is large and viscous drag can be neglected. Exceptions include water vehicles at slow speeds and conditions within the boundary layer, where the Reynolds number is small and viscous drag dominates. (Another example is microscopic organisms, where the Reynolds number is very tiny indeed!) At _low Mach numbers_: Viscous drag increases linearly with speed. Impact drag increases as the square of speed. As noted, impact drag is generally the only drag component that matters. High Mach numbers - applicable to the original suggestion of extreme velocity projectiles - are more complicated, and I don't know of simple formulas. I _think_ the speed dependence may even differ for objects of different shapes, but I'm surely no expert on this subject. ------------------------------------------------------------------------- Steve Willner Phone 617-495-7123 Bitnet: willner@cfa 60 Garden St. FTS: 830-7123 UUCP: willner@cfa Cambridge, MA 02138 USA Internet: willner@cfa.harvard.edu