US Air Force successfully test drops NUCLEAR gravity bomb

[Deleted]

The warhead will be a dial-a-yield warhead (0.3 kt, 1.5k, 10kt and 50kt).

Interested to know how this works...

[Krawu]

Interested to know how this works...

Here you go.

Not an awful lot to go on, but it very roughly outlines how the technology works,

[Deleted]

Here you go.

Not an awful lot to go on, but it very roughly outlines how the technology works,

Many thanks!

[Skroe]

Interested to know how this works...

https://en.wikipedia.org/wiki/Variable_yield

-Varying primary yield by boosting with fusion, using small amounts of deuterium / tritium (DT) gas inside the primary fission bomb to increase its yield by supplying additional neutrons from DT fusion at the beginning of the fission process. Typically, the gas is injected a few seconds before detonation and the amount used can be preset e.g. zero, 25%, 50% or all of the gas.

-Changing the primary yield by varying the timing or use of external neutron initiators (ENIs).[1] These are small particle accelerators that cause a brief fusion reaction by accelerating deuterium into a tritium target (or potentially vice versa), producing a short pulse of energetic neutrons. Precise timing of the ENI pulse as the nuclear primary's pit is collapsing can significantly affect yield, and the rate of neutron injection can also be controlled.

-Shutting down the thermonuclear secondary, either by firing the primary at low enough yield that it does not compress the secondary sufficiently to ignite, or by blocking energy transport inside the warhead briefly as the primary is firing using shutters or a similar mechanism. If the primary's energy starts to disperse through the radiation case before being focused on the secondary then the secondary will likely never detonate.

Also interesting in regards to the B61 Mod 12:

Increasing the the warhead explosive yield and decreasing the miss distance both improve the lethality of a warhead. However, increase the accuracy (decreasing the miss distance) is the more effective. Making a weapon twice as accurate has the same effect on lethality as making a warhead eight times as powerful. Phrased another way, making the missile twice as precise would only require one-eighth the explosive power to maintain the same lethality. Hence miniaturization of warheads and precision of delivery hasa been the course of US nuclear weapons development. An example may help.

The Minuteman-2 missile has a one megaton warhead and a CEP of 0.3 nautical miles. It's lethality rating is 11. When converted to a Minuteman-3 with three 170 kiloton MIRVs and a CEP of 0.2 nautical miles, the total lethality of the missile - counting all three warheads - rose to 23. By narrowing the CEP one-third and mirving, the hard kill target probability for the full payload was almost doubled, from 13% to 24%, with only half the megatonnage.

[Gaaz]

Interested to know how this works...

It does not. These are all different warheads. There is no switch to regulate the explosion. Unless you plan to make a dirt bomb that is. Basically, US develops a new carrier that can house several different low yield warheads. It does not mean that a single warhead is designed to explode in 50kt or 10kt regime with a selector switch. Nuclear devices do not work that way.
Potentially you can change compression explosion to be unbalanced, and reduce the explosion strength. But that would make all radioactive materials that did not undergo a reaction to just be spread all over the area, making the device "dirty". But in that case, you might as well use a normal TNT explosion to just blast a barrel of Uranium over an area. The effect would be practically the same and much cheaper.
North Korea by the way has never achieved a "clean" detonation. Their nuclear program only managed to create dirty devices, with only 20% mass in nuclear reaction. The rest 80% is "dirt". Unless something has changed in recent years that is.

[Deleted]

snip

Cheers, Skroe, variable payloads adds a whole new dimension to indirect fire...

[Skroe]

It does not. These are all different warheads. There is no switch to regulate the explosion. Unless you plan to make a dirt bomb that is. Basically, US develops a new carrier that can house several different low yield warheads. It does not mean that a single warhead is designed to explode in 50kt or 10kt regime with a selector switch. Nuclear devices do not work that way.
Potentially you can change compression explosion to be unbalanced, and reduce the explosion strength. But that would make all radioactive materials that did not undergo a reaction to just be spread all over the area, making the device "dirty". But in that case, you might as well use a normal TNT explosion to just blast a barrel of Uranium over an area. The effect would be practically the same and much cheaper.
North Korea by the way has never achieved a "clean" detonation. Their nuclear program only managed to create dirty devices, with only 20% mass in nuclear reaction. The rest 80% is "dirt". Unless something has changed in recent years that is.

You are not correct about this.

Modern US nuclear warheads are electronic dial-a-yield within a single warhead that can do any of those yields. The warhead yield selection is part of the Permissive Action Link access code to enable detonation.

[Gaaz]

You are not correct about this.

Modern US nuclear warheads are electronic dial-a-yield within a single warhead that can do any of those yields. The warhead yield selection is part of the Permissive Action Link access code to enable detonation.

Nuclear devices are simple and complex at the same time. My father is a former Special Forces operative engineer, tasked with disarming nuclear mines and command centers in Eastern and Western Europe. Or manning those command centers. If 100% of the yield undergoes a reaction cycle, there is nothing you can do about it. The explosion is going to have the same effect no matter what gas you inject in it, or what particle accelerator bombards it at the same time. It is as simple as that - 100% reaction = 100% detonation strength. You can affect the strength of an explosion by affecting the compression cycle, or the primary detonation. If compression will not be uniform, then not all material will undergo a reaction cycle. The explosion will be smaller in yield. But that also means that unused material is scattered all over the area, effectively making a dirty bomb. Contrary to movies and popular literature, if you are out of time, the easiest method of disarming a nuclear explosive device if you have an access to the core is not to pull wires out of it, and not cut the red one to stop the timer, but to blow it up. If you disrupt the containment integrity just enough to even make the subsequent detonation uneven, this will result a much weaker yield detonation. But that also means contamination of the area.
Long story short, you can not make "clean" explosions vary in power. If you reduce the explosion in power, i.e. not use the full yield potential, this makes it a dirty bomb. Think in terms of long lasting contamination, Chernobyl, Fukushima etc...
Therefore, all this variable strength is nothing but publicity stunt. I can not think of many reasons to intentially decrease explosion yields of a device and intentially contaminate an area. Unprotected humans will recieve lethal doses of radiation from either cases. Tanks and armor that are designed to withstand chemical and radiation contamination will hardly be affected by the dirt and suffer less damage from an initial explosion. Area denial? But it is not like people will move in right after an explosion - radiation will be lethal in any case.

[Somewhatconcerned]

Glad we're cutting NIH funding for this stuff!

[yetgdhfgh]

The Russians dropped the largest nuke ever with the Tsar Bomb which yelded about 57MT https://en.wikipedia.org/wiki/Tsar_Bomba

USA is suppose to be number 1 so we need to create a 100 MT bomb (which the tsar bomb was suppose to be)

No more pussy footing we need to create a doomsday bomb with the US flag on it!

[HumbleDuck]

Yea, cause that's what made US win the war last time, Nuclear weapons. Oh wait,...

[Tierbook]

Yea, cause that's what made US win the war last time, Nuclear weapons. Oh wait,...

We talking about WW2?

[Kellhound]

Let's be clear what the purpose of this bomb, the B-61 Mod 12, is, since scanning over this thread, nobody even bothered to talk about that.

The B61 Mod 12 is the first step of the US's 3+2 Nuclear modernization plan.



Nuclear weapons are tremenously expensive to own in large part because they are all tremendously specialized and all require a standing army of industry to support them. The US build dozens of different types of nuclear weapons over the decades and as technology improved and types became more homogenized, retired entire classes (and subclasses) of nuclear weapons to save money.

The B61 Mod 12's advances are a highly accurate (1 meter error) GPS capability, which will make it the most accurate nuclear weapon the US had (the latest W76s and W88 have 5m accuracy, but are going to be 1m). This will allow the following things to happen.


-> The warhead will be a dial-a-yield warhead (0.3 kt, 1.5k, 10kt and 50kt). The US will allow consolidate the entire stockpile of older B61 Mod 3, 4, 7 and 10s into the 12 because they don't have dial-a-yield and are locked at specific sizes.

-> The new guidance's accuracy will allow the warhead to be overall smaller in yield at it's max setting - only 50 kilotons. Prior nuclear bombs never had much focus put into accuracy (because why would you ever ever need an accurate, enormous explosion? That's a contradiction of sorts) or the technology didn't exist to make them accurate, so they were huge. The earliest bombs, which had accuracy in the realm of a kilometer, were enormous in order to ensure they would hit the thing they were intended to hit. With B61 Mod 12's guidance, the bomb can be made much smaller, even at it's largest yield.

-> The B61 Mod 12's accuracy will allow for the retirement of the 1.2 Megaton B83 "Citybuster", the US's largest strategic weapon. Yes, replacing a 1.2Mt bomb with a 50kt highly precise bomb is an even trade. This, in conjunction with the retirements of the B61 3/4/7 and 10 will allow for there to be just TWO types of nuclear bombs in the entire inventory: the B61 Mod 12, and the B61 Mod 11 (a nuclear bunker buster meant for attacking silos and hardened sites). Consolidating from 5 bombs to 2 will save a lot of money.


More broadly, after the B61 mod 12 program, the same thing will be happening with US ICBM and SLBM warheads. The older W78, W76 and W87 warheads, and the newer, advanced W88 will all be replaced with three new independently designed warheads IW1, IW2, IW3, all based on W89 and W91 designs. Unlike the existing Warheads, they'll be able to be mounted on SLBMs AND ICBMs. The need for three is driven by the need for type-reliability redundancy: if one type has to be taken out of service due to a problem or for maintenance, the US still has two warheads types to replace them and deter with.

Probably not with the B61 mod 12, but almost certainly with the IW1, IW2 and IW3 warheads, the US will have to resume nuclear testing. Every single nuclear warhead in service was tested before testing was halted, so the're known they work. When George W Bush proposed the Reliable Replacement Warhead, the W89 was chosen as the basis for it because it was the last tested, but unproduced warhead. If one of the IW's is based on the W91 as theorized, or even an all-new design, certification would almost certainly require testing to ensure deterrence.

- - - Updated - - -



The guidance system of the B61 mod 12 is the biggest change. It's based on the JDAM's nose / tail assembly.

Oh man, you beat me to it.....

[Hammerfest]

These bombs are more properly called "free-fall" bombs.

Besides, "gravity" doesn't exist.

[Alvito]

It might not be revolutionary, but it sure is showing Kim power of the US. NK cannot do this, US can, with ease.

That type of pissing contest is a loser for both sides and any spectators. Two lunatic ego tripping leaders having a barking contest has a billion ways to go wrong and few that it works out well.

[Kellhound]

Nuclear devices are simple and complex at the same time. My father is a former Special Forces operative engineer, tasked with disarming nuclear mines and command centers in Eastern and Western Europe. Or manning those command centers. If 100% of the yield undergoes a reaction cycle, there is nothing you can do about it. The explosion is going to have the same effect no matter what gas you inject in it, or what particle accelerator bombards it at the same time. It is as simple as that - 100% reaction = 100% detonation strength. You can affect the strength of an explosion by affecting the compression cycle, or the primary detonation. If compression will not be uniform, then not all material will undergo a reaction cycle. The explosion will be smaller in yield. But that also means that unused material is scattered all over the area, effectively making a dirty bomb. Contrary to movies and popular literature, if you are out of time, the easiest method of disarming a nuclear explosive device if you have an access to the core is not to pull wires out of it, and not cut the red one to stop the timer, but to blow it up. If you disrupt the containment integrity just enough to even make the subsequent detonation uneven, this will result a much weaker yield detonation. But that also means contamination of the area.
Long story short, you can not make "clean" explosions vary in power. If you reduce the explosion in power, i.e. not use the full yield potential, this makes it a dirty bomb. Think in terms of long lasting contamination, Chernobyl, Fukushima etc...
Therefore, all this variable strength is nothing but publicity stunt. I can not think of many reasons to intentially decrease explosion yields of a device and intentially contaminate an area. Unprotected humans will recieve lethal doses of radiation from either cases. Tanks and armor that are designed to withstand chemical and radiation contamination will hardly be affected by the dirt and suffer less damage from an initial explosion. Area denial? But it is not like people will move in right after an explosion - radiation will be lethal in any case.

You are thinking about simple fission bombs, not thermonuclear bombs.

[HumbleDuck]

We talking about WW2?

WW2 or Korean war, you choose.

[Gaaz]

You are thinking about simple fission bombs, not thermonuclear bombs.

I am thinking of any potential nuclear explosive device human kind has yet created. They all operate on a very similar principle when it comes to chemistry. The 2 stage H-bombs use reaction energy in a very similar way to the simpler one stage bombs. The difference is in scale. But whatever the size, if you use 100% of your core in the reaction, no matter how you treat it, the explosion strength will be the same. Energy release by a decaying particle is a near constant in this case. You can not affect it by injecting any gas, liquid or solid. The only way of reducing the strength of an explosion is to make not all 100% material react. But unused material will not magically disappear. It will contaminate the area.
If you want a nuclear explosion - use full yield. If you want a dirty bomb - strap half a ton of TNT to a barrel of Uranium 238 and blow it up above the area. Cheaper and more effective that way. Claims that nuclear devices can be regulated in terms of yield is just a publicity stunt for the masses. They can be, at the cost of making the explosion dirty. And no sane person is going to opt for that option wether it is from a military, or from humanitarian point of view (if that term is even aplicable).

[Skroe]

Oh man, you beat me to it.....

Don't worry, there's plenty of chances to get all our licks in! That was just on page 3 of the thread. Ulmita hasn't even made his appearance yet to do his "Russian nooks = best nooks, GPS/INS doesn't work cuz of magic" schikt.

It's not an MMO-Champ nuclear thread until it's 30 pages long and polluted as such.

[Kellhound]

I am thinking of any potential nuclear explosive device human kind has yet created. They all operate on a very similar principle when it comes to chemistry. The 2 stage H-bombs use reaction energy in a very similar way to the simpler one stage bombs. The difference is in scale. But whatever the size, if you use 100% of your core in the reaction, no matter how you treat it, the explosion strength will be the same. Energy release by a decaying particle is a near constant in this case. You can not affect it by injecting any gas, liquid or solid. The only way of reducing the strength of an axplosion is to make not all 100% material react. But unused material will not magically dissapear. It will contaminate the area.
If you want a nuclear explosion - use full yield. If you want a dirty bomb - strap half a ton of TNT to a barrel of Uranium 238 and blow it up above the area. Cheaper and more effective that way. Claims that nuclear devices can be regulated in terms of yield is just a publicity stunt for the masses. They can be, at the cost of making the explosion dirty. And no sane person is going to opt for that option wether it is from a military, or from humanitarian point of view (if that term is even aplicable).

The introduction of tritium has a significant impact on the yield, both in fission and as the primary fuel for fusion. Controlling the amount of tritium available controls the yield.