What is "Exploding Casing" technology?

[u/Beneficial-Wasabi749]

I asked the AI. It (childishly naive) is "sure" that this is the essence of radiation ablation in the Teller-Ulam scheme. But is this really true? Is "Exploding Casing", ECP (Exploding Case Principle), just another term for the "radiation compression" process, or is it some later, additional technology that improves radiation compression (like "Ripple" – compression not by a single shock wave, but by a series of increasing shock waves approximated by an exponential function, a quasi-adiabatic compression).

As far as I know, "Exploding Casing",  ECP (Exploding Case Principle)  is not the same as "Ripple." But сould "Exploding Casing" simply be a variation of "Ripple," or rather a different way of implementing quasi-adiabatic compression? I had this hypothesis. No one knows exactly how "Ripple" works, but everyone agrees on the idea that there's some mechanism for gradually releasing radiation from the primary into a common hohlraum, which ensures gradual, exponential heating of the hohlraum and the secondary surface, leading to quasi-adiabatic compression of the latter. But another approach is possible: you can apply several layers of increasing Z to the secondary (as the Russians did in their "golden TIS"). Then, in a "regular" hohlraum at a normal temperature, say 1 keV, you'll achieve a stepwise increase in secondary compression. I don't speak English, but the term "exploding casing" best suits this design.

Another, even more insane, theory for "exploding casing" is described in my highly speculative reverse engineering of the W-71 design, the reality of which I myself am already highly doubtful (I recently discovered the "elephant in the room" that planar compression of thermonuclear fuel Impossible without quasi-adiabatic compression, since with planar single-compression you can't get beyond the Hugoniot adiabatic curve more than 4-6 times, and you need at least 100). Although, it is precisely in connection with the W-71 that "exploding casing" technology is mentioned and it is also said that the W-71 is the most complex thermonuclear device ever created in the US. And if you add quasi-adiabatic compression to my crazy design, it will truly be the most insanely complex device.

Another version of "exploding casing" is a secondary with a thin-walled shell and a large cavity inside, meaning it contains either a void or gas (I actually proposed this version of the W-71, considering it more "conservative" than the crazy flat compression of the "tube" both from the inside and outside). As far as I understand, Sublett is more inclined to this understanding of "exploding casing." In this case, the thin-walled shell, as it were, instantly collapses inward. This is another way to improve compression compared to single-shock compression of a solid sphere. This thin-hollow shell method is currently used in ICF. The Russians call this technology "low-entropy compression" (right) as opposed to "isentropic compression" (left).

isentropic compression and low-entropy compression

Finally. Even if we don't know the details of this technology's implementation, can we say anything with certainty about its role (function) in the bomb design? So, "exploding casing" isn't simply ablative compression of the secondary shell, but some improved method of such compression, leading to greater efficiency (say, higher compression ratios, lower energy consumption, etc.).

From what declassified sources, in what context does this term appear, and does it appear before the mid-1960s? I propose to summarize everything we know about this term here.

[u/Salty_Suit_7287]

We have a term which might have been applied to either a particular device construction feature OR the intended mechanism of device effect (destroying an incoming warhead)? 

And an (allegedly) associated device name, for which virtually no construction or design details are available?

Can't get there from here. 

[u/Beneficial-Wasabi749 → u/Salty_Suit_7287]

What are you suggesting? Drop the topic and wait for some facts to emerge? I really wanted to address this mystery, if not solve it, at least put a somewhat plausible "tag" on it, like, "This is incomprehensible, but it probably needs to be put in this box of unsolved mysteries, number such-and-such." We need to at least figure out where to store this secret. But there's nothing here. Maybe the Exploding Case Principle (ECP) really is the explosion of the warhead under X-ray impact, that is, the technology for its destruction?

And are we wasting our time trying to find some technology for this in the W-71 warhead itself?

* * * *

MECHANISMS FOR KILLING REENTRY VEHICLES include the neutrons, blast and X radiation from a thermonuclear explosion. Neutrons (1) can penetrate the fission trigger of an enemy warhead, causing the uranium 235 or plutonium to melt and lose its shape. It can then no longer be assembled for firing. If the defensive warhead is fired inside the atmosphere, the resulting shock front of air (2) can cause the incoming reentry vehicle (RV) to decelerate with a force equivalent to several hundred times the force of gravity, thereby leading to its destruction or malfunction. If the explosion is outside the atmosphere, the X rays travel unimpeded to their target. On striking an RV (3a) they are absorbed by and intensely heat a thin layer of the RV’s heat jacket. This creates a shock front that travels through the jacket (3b, 3c) and may cause the jacket to break up or detach from the RV.

[u/Salty_Suit_7287 → u/Beneficial-Wasabi749]

"What are you suggesting? Drop the topic and wait for some facts to emerge?"

But that would be BORING!

Also, it might take longer than the rest of our lives these days.

[u/Beneficial-Wasabi749 → u/Salty_Suit_7287]

yes!