Sure if you try to catch a bullet with a bullet you're making your life harder. Anyway to increase the interception surface/volume ?

> Any way to increase the interception surface/volume ?

Yes - the usual way is to fit the interceptor with a nuclear warhead (see Sprint, Spartan and Nike Zeus on the US side - Fakel 51T6, Novator 53T6 and S-300PS/S-300PM on the Soviet side)... But it has sort of fallen out of fashion...

These weapons used enhanced radiation warhead (neutron bomb). The mechanism was use of neutron flux to disable incoming nuclear warhead.

Radiation hardening the warhead against this type of attack would make it less effective.

Wouldn't the neutron flux mess with the properties of the nuclear payload? Shielding against a neutron flux from nuclear explosion probably not practical given the sizes warheads.

Light atoms are used to slow down fast neutrons. Thermal neutron absorbers (large neutron capture cross section) like boron, lithium or cadmium is used for shielding.

Li6H is perfect for shielding warhead. Li6H (Lithium-6 hydride) contains hydrogen to slow down neutrons and lithium to absorb them. It has hightest hydrogen content of any hydride, high melting point and can be casted.

The shielding takes some space and the warhead yield is smaller than without shielding. The goal is not to completely block neutron flux but to reduce it to the level where exploding countermeasure must be very close.

If I recall correctly the case of the re-entry vehicle tends to be stuff like depleted uranium, which is pretty good protection against neutron flux up until the point where it begins significant breeder contributions. You'd basically have the hit the vehicle anyway to get close enough for that.

Uranium or lead, heavy nuclei that shield well against gamma radiation would do little for neutrons.

Neutrons needs something with light atom like hydrogen - water or maybe polyethylene and lots of it to slow down. So a small nuclear explosion which emits a neutron pulse might work pretty well. It would hellish if it somehow exploded over a population center, though. Didn't get hit by the ICBM (good). Everyone's bones melted (bad).

Not really, I mean, your opponent is the one controlling the size of the thing you're trying to intercept and they're not going to be trying to make things easier on you. The only viable option given that is to go for area saturation and basically play the odds, but that's really expensive because not only do you need lots of interceptors in that case, but each one needs to be capable of getting a kinetic kill since there's no guarantee which one (if any) will actually hit. At some point I imagine the interceptors become a bigger danger to each other than they are to the thing you're trying to intercept.

I see. Were there research into non destructive interception ? a missile catching up another one and binding to it to divert it ?

That would be even harder because now you need to match position and velocity instead of just position.

I understand but I'm still curious..

Explode the interceptor?

This doesn't work well for ballistic missiles. A few ounces of shrapnel doesn't knock the missile very far from it's trajectory. You'd have to get lucky to break the fuse, and even then you'd have a big hunk of explosives heading toward the target and making a big crater. Plus a lot of old missiles have such simple fusing systems that you probably won't break them with just a bit of shrapnel anyway.

As I understand it, the only serious "explode the interceptor" proposal was to use nuclear interceptors against ICBMs. That provides a modest radius of non-projectile destruction, and more importantly provides a large radius of fuse/control-disrupting radiation.

So when it comes to "shooting down a Scud near the ground over a city", you're exactly right. Blowing up your interceptor only works when you've got a high-tech target and are willing to make quite a mess yourself to stop the thing.

Well detonating nuclear warheads (literally) near some important asset of yours is probably always some kind of last ditch effort.

I did a tour of the Nike missile site in the Marin Headlands / Golden Gate Park once.

They were very careful to "neither confirm nor deny" whether the site ever had nuclear payloads, but they _did_ make a point to tell everyone that the beautiful mechanical targeting computers had Sacramento programmed in as a target, "just in case"...

Not necessarily, it would be going off pretty high. Much higher than in this video with people directly underneath.

https://www.youtube.com/watch?v=BlE1BdOAfVc

Yeah, probably not the sort of thing you go and do to stop a 5-kiloton conventional warhead.

having something deployed near encounter ... damaging flare/shrapnel, a flock of timed explosive ...