El Cid (or someone else knowledgable on the matter), are Chinese silos dense packed or spread out? Also, to what extent do they rely on camouflage and to what degree on hardening?

There is an extensive article about the subject of HANE, or High Altitude Nuclear Explosions, in this month's issue of Scientific American. As to dial-a-yield in regard to EMP, most of a nuclear weapon's energy is released in the form of X and Gamma Rays, which in the atomsophere are largely absorbed and reemitted as IR. Higher up there is less air to do this and the hard radiation is absorbed more slowly. Further, because of the altitude, the EMP is thus distributed over a wider area. Finally, the weapon discharges massive amounts of ionized particles into the upper atomosphere, which will stongly affect radio communications and degrade or destroy the sensitive electronics of satillites there. Most military satillites orbit higher, but not all. There was also an article in Pop Sci a few years ago about a conventional EMP weapon mentioned in another post. It was quite simple, involving the detonation of a cylinder of explosive wrapped with a layer of material with a high capacitance. Total cost: $1000.00 with parts from Radio Shack (- the explosives, you would have to go to Nevada or Montana to pick those up with a driver's license, at least pre911)

I remember reading about "frisbee" nukes some time ago. This was a saucer shaped warhead that supposedly could direct about %70 percent of a nuke charge into a small conal shape below the disc for "precision" strikes. This was in a magazine so it wasn't that classified. Wonder if the Chinese are playing with that kind of weapon for Taiwan. A couple of 200k frisbees oughta be just enough.

ok, I'm confused, how does anyone make a nuke that is a focussed/shaped charge, i.e. a nuclear version of a claymore? At the technical level I can't see how that is possible.

Focusing a nuclear blast is not really any different than any other kind, its just a matter of scale. The U.S. gov't investigated the possibility of using a series of atomic bombs to boost a large spacecraft of satillite into orbit, called Project Orion. In a similar vein, the U.S. experimented with NERVA, nuclear energy rocket vehicle application, which would direct the exhaust of a nuclear reactor to power a rocket. There are also thermionic rockets / ion drives which use low-grade radioactive material cast into cylinders and surrounded on all but the 'exhaust' side by shielding. As to focusing the blast of a nuclear weapon, you could use geography, like mountains, to channel the effect, or a material which was reflective to hard radiation (which may or may not be possible, I tend to think such radiation would sink into anything). Your best bet might be to travel to Alaska and ask the guys running HAARP, the high altitude auroral research project, which attempts to focus / affect the ionosphere with 2gW transmitters. They might be able to collect the radioactive debris from a high altitude blast and dump it on someone. Lastly, the shaping of the bomb casing and fusion material might help. If the bomb were designed in a bell shape, with the atomic detonator where the bulbous part of the ringer would be on a bell, and the fusion material running the length of the stick, a very heavy outer coating of uranium (the bell) may serve to focus some of the blast downward before it too fissled and released all of its energy outward. Try looking at: nuclear bunker busters, x-ray lasers

I could work out how to make a geographic/terran influenced effect, I just had problems working out how you could convert a nuke into an overgrown claymore. It's one for more research I think ;) I still fail to see how you could create a shaped charge effect on a nuke. It would be turned into pixie dust before anything could effectively influence that plume out.

I have problems with the idea of focusing a nuclear blast with much efficacy, though a heavy casing would certainly help to direct some of the blast before it decayed (remember that nuclear reactions do occur on the order of nanoseconds) I still agree that most of the casing would dissolve, melting into the sphere. However, I feel that the xray laser may be an excellent way to shape that charge, see following: from:http://www.fact-index.com/l/la/laser_applications.html#Military "Another idea to come from the SDI project was the nuclear-pumped X-ray laser. This was essentially an orbiting atomic bomb, surrounded by laser media in the form of glass rods; when the bomb exploded, the rods would be bombarded with highly-energetic gamma-ray photons, causing spontaneous and stimulated emission of X-ray photons in the atoms making up the rods. This would lead to optical amplification of the X-ray photons, producing an X-ray laser beam which would be minimally affected by atmospheric distortion and capable of destroying ICBMs in flight. The X-ray laser would be a strictly one-shot device, destroying itself on activation. Some inital tests of this concept were performed with underground nuclear testing, however, the results were not encouraging. Reseach into this approach to missile defense was discontinued after the cancellation of the SDI program." I don't know why it wasn't encouraging.

"I don't know why it wasn't encouraging." Probably economies of scale. ;) OTOH if you could create a pulse detonation process then it might have merit - cycle up the power plant and use it to discharge at a predefined point. Recharge cycles would be interesting. A bit like a nuclear powered pulse engine which is a cycling detonator..

Simple, it wasnt encouraging because at the time the explosion not just vaporized the device too fast but also a gigantic chunk of the explosive energy and hence its gamma ray emissions were wasted because they werent all bombarding the rods. In other words the lasers didnt work becaused their explosions dissipated too much and too quickly, which in turn resulted in a weakened beam.

Nuclear Pumped X Ray lasers are a one time thing. They destroy themselves in the process of firing. I wonder if results could be made more "encouraging" by spreading out the glass filaments in a parabola with the nuclear pumping device at the focus. If the parabola were quite large perhaps the x-rays would be insufficient strength to vaporize the thing immediately. Or, one could use a moderating substance which would absorb and re-emit the x-rays, slowing down their effective rate of propogation. Hard to test with a ban on nuclear tests.