The implosion system Iran worked on during the AMAD project was ~55 cm in diameter. The multipoint initiation approach without lenses and only two detonators should make it easier to ruggedize: isis-online.org/isis-reports...

The implosion bomb design Iran allegedly worked on 20 years ago with the help of Vyacheslav Danilenko was unlensed an smaller than the Chinese CHIC-4 design peddled by A.Q. Khan (55 cm vs. 80-90 cm diameter). isis-online.org/isis-reports...

According to Hui Zhang's study it took 3-5 weeks to make the core once HEU was available, the other components had been completed beforehand. It also says the bomb used a different implosion system than the dual-speed explosive lenses used in early US bombs: npolicy.org/wp-content/u...

We do have pretty extensive information on their efforts developing a compact implosion system over twenty years ago: isis-online.org/isis-reports...

The bomb design Iran pursued in the past was for a compact uranium implosion bomb intended for the Shahab-3 MRBM: isis-online.org/isis-reports...

IAEA considers all HEU (so 20% and up) as directly usable for nuclear weapons. Though lower enrichment means higher critical mass and less practical as a deliverable weapon. But difference between 20 and 90% is small in terms of separative effort. Between Iran's 60% and 90% it's extremely small.

LANL weapons designers J. Carson Mark and Ted Taylor, for example.

A few hundred ton yield is all that's needed for fusion boosting to work, which eliminates the preinitiation issue.

...and suggests that system was likely similar to the MPI system of the known Iranian AMAD design. Though I know about the problems with the unlensed approach - perhaps it's more likely they moved towards two point air lens designs?

Could you elaborate on what you believe that approach is or is that not something that should be shared? 😅 On Reddit Carey Sublette said the "tile focusing element" described in the article sounds like an air lens - in the full paper Hui Zhang states that China developed a new system in the 80s...

2015 final IAEA report on Iran's nuclear program (PDF): www.iaea.org/sites/defaul...

I too would be skeptical about Israeli claims about this strike, though an apparent resumption of Iranian weaponization efforts shouldn't come as a surprise now.

What matters is that both US intel and the IAEA determined that weaponization efforts ceased around 2003 and had long been shelved by the time of the JCPOA. Bibi's revelations didn't change that or reveal a violation of the deal.

The AMAD plan and the Parchin site were known long before 2018, Bibi's presentation didn't reveal much more information than what had already been reported over years by the IAEA.

IIRC the US assessment is that Iran halted the weaponization program in 2003, while Bibi claimed it continued. This report suggests US and Israel agree that weaponization research may have resumed earlier this year.

These first showed up a couple of months ago. The wings on the smaller ones look different from Lancet, and afaik Lancets don't have foldable wings. They more closely resemble Israeli HERO drones. The larger ones look like Harop copies.