According to my understanding, only the VNIIEF and VNIITF are responsible for the development of nuclear weapons in the Soviet Union

But I know from wiki that VNIIA is also responsible for “nuclear weapon development”,so I wonder if VNIIA is only responsible for the development of nuclear weapon system(like detonation system,bomb shell,PAL system etc ) other than nuclear devices design？

/.Just was wondering if this is the right place to ask but does anyone have any good suggestions for movies about us atomic bomb testing besides trinity and beyond? Im looking for surface testing mainly.I apologize with this is not best place to ask.

I am relatively new to the topic of nuclear armaments, so I apologize if my understanding is incomplete.

It is astonishing to observe how the United States advanced from a 64 kg HEU pure fission design, like the "Tall Boy," which produced approximately 15 kilotons of yield, to a fission device of similar HEU quantity yielding around 500 kilotons ("Ivy King") in just a decade . This remarkable leap in weapon design exemplifies significant technological progress.

By the 1980s, it became possible to create warheads capable of delivering yields in the hundreds of kilotons, yet small enough to be carried by just two individuals, including the MIRV that could accurately strike its target. This development is particularly striking when considering that delivery platforms like the B-52 could carry payloads 3.5 times greater than those of the B-29, which was arguably one of the most advanced bombers of World War II. And this doesn't even include the radical advancements in missile technology during this time.

Following the Cold War, the pace of nuclear weapons development appears to have slowed, likely due to diminished geopolitical tensions and the general satisfaction among nations with the exceptional yield-to-weight ratios achieved in multistage thermonuclear weapon designs of the 1980s and 1990s.

I am curious to know whether there is still potential to improve the yield-to-weight ratio of contemporary fission, boosted fission, or thermonuclear weapons. If so, what technological advancements could drive these improvements?

I would appreciate an explanation that is accessible to those without a deep understanding of nuclear physics.

Thank you in advance for your insights!

Picture: “Davy Crockett Weapons System in Infantry and Armor Units” - prod. start 1958; recoilless smoothbore gun shooting the 279mm XM388 projectile armed with a 20t yield W54 Mod. 2 warhead based on a Pu239 implosion design. The projectile weight only 76lb/34kg !

Israel, at least officially, has never tested a nuclear bomb. Was it possible they actually did so in secret? There was the 1979 Vela Incident, which has been attributed to Israel and South Africa testing a bomb; what’s the consensus these days on what actually happened during the Vela Incident?

It was what looked like to me a 800-1000 kiloton airburst maybe a few miles from the park, obviously this was just intended as a horrific dream sequence (scared me as a child) that was purposefully dramatised to an extent but could the flash of thermal radiation really carbonise entire human bodies at that distance? The thermal pulse would last longer than a lower yield 20-100kt bomb, victims of Hiroshima and Nagasaki suffered similar burns but very close to ground zero and probably burned even more by secondary fires I’m guessing, would 30-50cal/cm2 burn that deeply into the skin it was like the air ignited and everyone and everything was continuously burning in the film and the shockwave blew them to dust it was very grim but in real life wouldn’t people just be severely burned as opposed to incinerated? Not that they wouldn’t die or wish they were dead it’s really the zone where you’d want to be indoors or at least shielded from the light.

Hey, I'm writing a script connected to Nuclear War breaking out in 1983 set in the U.K, à la Threads. What books should I read that can give me the best idea about how that would pan out? This can include prospective scenarios and general histories of Cold War UK. I already have an eye on Nuclear War in the U.K by Taras Young, but I'm looking for extra materials. Thanks!

I’ll admit I know less about the geopolitics and strategy of nuclear weapons than I do about their construction but I would like to read more about Iran’s current nuclear capacity, their possible targets, means of deployment and the political fallout from such an attack.

What I have been able to find suggests they may already have enough enriched uranium for a small weapon but sizes and timelines vary wildly.

Since most of their enemies have decent anti-ballistic missile capacity, what are some of the strategies that Iran might use to deploy such a weapon?

I know they are currently in a deepening conflict with Israel, another nuclear power, but what other targets might they be thinking about?

I would love a discussion or links to further reading.

In Pakistan's Pathway to the Bomb, there is this interesting titbit at page 196

Meanwhile, S. A. Butt was able to get his hands on the drawings of a French implosion device, which allowed the theoretical group to develop an altogether new explosive lens design by the mid-1980's

This is interesting, since although Paki-Chona collaboration is well known, AFAIK this is the first indication in a semi-official record of Pak warhead design advancing through espionage.

Does anyone have any clue which French device it could have been, considering the era. (mid 1980's).

I'm interested in seeing inside to see roughly how it works. I have a 3D printable design for the Fallout video game 'Mini Nuke' so making a 3D printable internal assembly would be cool.

[EDIT] Thanks all for the info so far, the drawings are great! Keep it coming, I'll share my final design in a future thread. :)

I’ve been reading a bit about fireball development, mainly to get a better understanding of the characteristic “double flash” of a nuclear explosion.

My understanding so far is this:

The growth of the fireball is initially propagated by X-rays superheating the air around the bomb, resulting in the initial peak in luminosity. This X-ray front eventually slows down and is overtaken by the shockwave initiated by the expansion of the vaporized bomb. At this point the shockwave is incandescent, but radiates at a lower temperature than the rest of the fireball. It is opaque, so it blocks light from the brighter fireball within, resulting in a decrease in luminosity. The shockwave continues to move outward and becomes transparent, allowing the bright fireball to shine through and resulting in the second luminosity peak.

What I’m not sure about is the reason for the opacity that causes the luminosity minimum. At one point I saw something about heating in the shockwave causing the formation of nitrogen dioxide, but this was on Wikipedia and seems to have been redacted since. So I don’t necessarily trust that claim.

Is it just a result of compression or something to do with vaporized bomb material?

I also understand that the absorption and emission lines for materials are the same, but I didn’t think this principle applied to absorption of a whole blackbody spectrum.

So I'm writing a book about nuclear apocalypse, and I want to get as many details correct as possible. I couldn't find a clear answer, so is nuclear winter a guarantee in the event of an apocalypse?

My understanding of thermonuclear weapon designs from Wikipedia and the Nuclear Weapons Archive is that a key component of the secondary is a U-235 or Pu-239 spark plug, which may be in the centre of the secondary or part of a tamper. A consequence is that a fully "clean" secondary is not possible.
https://en.wikipedia.org/wiki/Thermonuclear_weapon

Under radiation compression the spark plug fissions to produce neutrons. These are essential to create the tritium required for fusion fuel from lithium deuteride (LiD). Perhaps the most common reaction is:

Li-6 + n -> T + He-4 + 4.7829 MeV

The deuteride component of the LiD then fuses with the liberated tritium as follows:

D + T -> He-4 + n + 17.588 MeV

This is the main fusion reaction in thermonuclear weapons.

However, a number of threads on r/nuclearweapons talk about modern weapons not having sparkplugs.

How do such designs work?

I'm aware that the Jetter Cycle is able to create some level of self-sustaining tritium production. Remembering Li-6 and D (deuterium) are the two elements in abundance in the fuel.
Li-6 + n -> He-4 + T
T + D -> He-4 + n
n + Li-6 -> T + He-4 etc.
However:

1. An initiator of some sort, such as a spark plug of D + T gas is needed to provide initial neutrons, and
2. There will inevitable be neutron loss, so it seems an additional source of neutrons seems to be required.

This post has been automatically removed once? Why? Here's a shorter version.

I came across an interesting document:
https://ia801609.us.archive.org/28/items/DeclassifiedNuclearWeaponDevelopmentHistoryReports/Russian%20nuclear%20warhead%20designs%20and%20delivery%20system.pdf
It purports to show a lot of information about Soviet/Russian TN weapons design including photos of many warheads, descriptions of weapons development and tests. There are comparisons and comments on US/UK designs. Unfortunately it's mostly a jumble of information. But many times the Russian text is translated into English.

Does the document appear genuine? Can someone familiar with Russian explain things more clearly?

On pages 7, 8 and 12 it describes the double-primary weapon design ("...first tested on 23 February 1958 and still in use today"), which they describe as superior to US/UK designs in a number of respects. The double-primary design means X-rays are more uniformly distributed in the secondary radiation shell. It doesn't require a foam/plastic filling to help produce uniform X-ray compression of the secondary. It is intrinsically cleaner - requiring less U235 in the secondary.

I came across an interesting document:
https://ia801609.us.archive.org/28/items/DeclassifiedNuclearWeaponDevelopmentHistoryReports/Russian%20nuclear%20warhead%20designs%20and%20delivery%20system.pdf
It purports to show a lot of information about Soviet/Russian TN weapons design including photos of many warheads, descriptions of weapons development and tests. There are comparisons and comments on US/UK designs. Unfortunately it's mostly a jumble of information. But many times the Russian text is translated into English.

Does the document appear genuine? Can someone familiar with Russian explain things more clearly?

On pages 7, 8 and 12 it describes the double-primary weapon design ("...first tested on 23 February 1958 and still in use today"), which they describe as superior to US/UK designs in a number of respects. The double-primary design means X-rays are more uniformly distributed in the secondary radiation shell. It doesn't require a foam/plastic filling to help produce uniform X-ray compression of the secondary. It is intrinsically cleaner - requiring less U235 in the secondary.

They claim a double-primary results in a 2.5 fold increase in efficiency! Hard to believe.

There is a drawing of what appears to be a triple stage weapon at the bottom of page 8. It has combined primaries and secondaries on either side of a central ternary.

There is much more in this document. Has anyone stumbled on it before?
I found it in a drop down menu for PDFs on the RHS of the following page. It's the last of 5 files.
https://archive.org/details/DeclassifiedNuclearWeaponDevelopmentHistoryReports

Can anyone help with the significance of the "Declassified Nuclear Weapon Development History Reports" site and the main "www.nukegate.org" linked archive.

So if the Tsar Bomba had a thermonuclear warhead, and the warhead used a normal nuke to set off another nuke, which would multiply the power a lot, would a 3 layer stack (as in, a nuke used to induce supercritical state in a "super nuke" which would be used to induce a supercritical state in a "mega nuke") be possible? If so, how far could you stack it past 3?

Edit: I think his statement is basically true, that Einstein's prestige is what got Roosovelt's attention. (?) Or, was the Maude report out already? Also, NDT does do some good science work.

https://www.youtube.com/shorts/movDYUI0Fx4?feature=share

Just curious how much of the text of the second letter, was Einstein's.

Hey everyone! As heard on the news, North Korea apparently has troops in Russia now and they may be deployed. In result, South Korea is threatening to send troops to Ukraine/go to war with North Korea. What will happen if this were the case? Wouldn’t more countries continue to step in and it could end up being another World War or nuclear war?

I came across this reference to hot expanded plutonium https://www.osti.gov/servlets/purl/10115425 pp7. It concerns the measuring of its EOS between 12-18 gm/cm^(3) density, which is interesting since none of the allotropes or alloys that I know of have a density as low as 12 gm/cm^(3) Does anyone have any idea what the low density form is that it refers to and to what use it might be put. I wondered if the Pu in the pit used a graded density of Pu?. The document states that the information is required for stockpile stewardship and test ban readiness

The remains of the tower were stolen in the 1980s and 1990s.

https://preview.redd.it/li0zoahnz1wd1.jpg?width=982&format=pjpg&auto=webp&s=7b947f535a4fcd660433226043d53e8eeb976d9c

https://preview.redd.it/makiiq9pz1wd1.jpg?width=982&format=pjpg&auto=webp&s=3f8f04033689042e5265fa7ea117f7e5fb6b2c54

https://preview.redd.it/ahmr0q9pz1wd1.jpg?width=978&format=pjpg&auto=webp&s=e9faa6a075ac28c5685913e980f1c0c4a378e200

I don’t understand it. They say it doesn’t exist and that everything is made up.

Edit: here is the post I made, scroll down till you get to elephant dude

https://www.reddit.com/r/NoStupidQuestions/s/uoHyVUbob2

The isotopes from fall out with very long half lives seem to be (corrected) Sr-90 and Cs-137. As far as I can tell the radiation they emit is beta, so the danger from them is if they are ingested.

How easy is it to prevent that, on a long term basis, once they are in the environment?

Is it possible to rid the body of them if they are ingested, or possibly overwhelm the isotope of each by consuming a lot of the stable version, as is recommended for Iodine?

Are they taken up by crops intended for consumption, or other parts of the food chain?