NationStates Jolt Archive

ADDED ISOMER SECTION AGAIN, WITH EDITS

There has been much confusion over nuclear weapons, I've noticed, and though occurrences like the glassing of Feazanthia don't happen that much anymore, I decided I would write a guide to exactly what happens when, say, a nuclear missile/suitcase bomb detonates. I hope if people know exactly how these WMD work, the RPs involving them might become a bit more fun for both sides. Tomorrow a blow-by-blow description of a nuclear attack on a modern city will be posted.

How I Learned To Stop Worrying...

I am going to assume that everyone who is reading this knows how a nuclear explosion works, but I will still explain anyways. Radioactive atoms are either ripped apart (fission) or fused together (fusion.) When either of these events happen, energy is released. Which is where the “bomb” part comes in. Originally, like the two bombs dropped on Japan by America, the process of fission was used. However, that was inefficient with only about a 1.5% efficiency rate for the first atomic bomb dropped. That means only 1.5% of the uranium was converted to energy. In most modern thermonuclear bombs, the fission side of the warhead is detonated by the fusion bomb in which it is encased; this increases the efficiency ratio, which is why the bombs dropped by America in 1945 are so weak compared to modern warheads.

After the bomb blows up, a lot of energy comes out, to put it simply. About 50% of this energy will be the actual blast/shock wave, but another 35% will go as thermal radiation and the remaining 15% is nuclear radiation. Of the 15%, only 5% is the initial gamma rays and streams of neutrons. (This is the EMP that knocks out electronics.) The remain 10% is the residual radiation, or “fallout.”

When the bomb detonates, within a millisecond a fireball forms. In the seconds or so, the fireball will rise at 100 meters/second, and this rapid expansion creates such a compression of air that a shock wave ensues. As the fireball expands, it cools from its maximum temperature of 300 million degrees Celsius, and within approximately a minute, (depending on the warhead yield,) it will be so cool that particles inside condense back together and, with the presence of water in the air, form little white droplets. Hence, “nuclear winter.”

The snow, though, really only occurs after an airburst, where the warhead is detonated at a height beneath 30 km (sorry, I use metric) but sufficiently high enough so the fireball does not come in contact with the ground. Any higher than 30 km and it is called a high-altitude burst, and the EMP produced will damage any satellites in the surrounding area. The surface burst, which may occur at or just above the ground/sea, deals the radiation and blast into a smaller area than an airburst. The fallout, however, is more suspectible to spread downwind. The last kind, suggested for use in Afghanistan by the DoD, is the subsurface blast. Here, the only dangers to the surface is the shock wave, unless the radiation penetrates the surface, but even then the thermal and nuclear damage is lessened.

Samtonia is become Death, destroyer of worlds...

What kills the most people in a city that has been struck with a nuclear bomb is not the fireball nor the radiation. The actual blast, the collapse of structures such as skyscrapers, and the pieces of flying debris, are responsible for most of the millions of deaths that would occur in a densely populated city. Immediately after the blast and the fireball, the greatest threats to those who had survived in an urban environment are the fires that still rage, suffering a prolonged death due to being rapped under debris, and lack of adequate and available medical help for burns and such.

In fact, the Department of Defence has simulated, and you can too with a program I list below, that a circle of 20 kt yield bombs would be more dangerous in an urban center than a single 1 mt bomb because the resulting fires would form a ring, trapping those in from the outside. And slowly burning everything in its path as the circle shrinks. In Hiroshima, such a circle of fire was responsible for thousands of deaths that the original blast didn't kill.

Tactical Nuclear Strikes?

There has been much fuss made about “tactical” nuclear strikes, in both NS and in real life. As compared to “strategic” nuclear strikes, which target enemy cities, tactical strikes target enemy armies, navies, etc. in a combat situation. The idea is that because this type of attack would not target civilians and not render entire cities inhospitable for years, they are acceptable and would not provoke strategic strike from the enemy. Read “Red Storm Rising,” and near the end, hate to give away spoilers, but near the end the idea of a tactical nuclear strike is brought up. Luckily, one of the characters realizes the stupidity and semantical tricks of this idea, and it never happens.

The problem with tactical nuclear strikes is that no matter how you are phrasing it, it is still detonating a nuclear missile over a countries land/sea, and killing their people. The long-term effects will still occur, and most likely the nation launching them will receive just as much international hatred as a strategic strike. And the enemy will retaliate with a strike against your cities, and you lose anyways. Of course, you might choose to use a high-altitude burst, thus not necessarily killing any human, but completely disabling an enemies satellite system. Or saving the world from an asteroid.

Red Tide and Thermonuclear War

If you decide to wage thermonuclear war, there are two types of targets to consider. This is a better way to define types of strikes than my tactical/strategic classification. All targets can be considered counterforce targets or countervalue targets.

Counterforce targets are typically military targets with retaliatory capabilities. These may include missile submarines, missile silos, submarine pens, command and communication centers. Attacking these will maybe cripple your enemies ability to respond, though if they even have an somewhat passable ABM system, they might be able to counterattack before you destroy the missile launching sites.

Countervalue targets are generally civilian targets that, if struck, will bring down a nation. Cities, power plants, industrial areas, transportation hubs, all of these are countervalue targets. The downside of attacking these targets is that your enemy will definitely know, and thus strike back, bringing you both down.

Which bring me to the ultimate reason nuclear war doesn't happen. There's a scary little policy America and Russia had back in the cold war, called MAD. That stands for Mutually Assured Destruction. Which is the reason there was the arms race. The idea behind MAD was that world peace and a lack of nuclear war could be assured if two opposing countries both had the same amount of nuclear weapons, and both would launch them if the other nation struck first. As long as both nations waited for the first strike, there would be peace. And it worked. Which is why nuclear will never happen, as long as all nuclear powers are aware of the consequences of launching a nuclear strike.

Bringing the end of the world that much closer...

Okay, now that I've told you how to wage thermonuclear war, I'm going to give you some design tips if you want to make your own. Did I mention Lindim has no nuclear weapons as a policy?

First let's talk about yields. A nuclear weapon's yield is the is its explosiveness as measured in amount of trinitrotoluene, or TNT. Thus, we would say that the atomic bomb dropped on Hiroshima was equivalent to detonating 12-15 kilotons of TNT, since its yield was 12-15 kt. Most of the warheads on a United States ICBM is about 300-500 kt, but the US military has developed much smaller warheads with a yield of only 1 kt. This warhead is probably designed for subsurface bursts or tactical strikes. The largest warhead tested, not developed mind you, but tested, was a 50 mt (that's MEGAtons) warhead. If you use a warhead with a yield under 100 kt mt, the amount of energy dispersed in the shock increases to about 60%, while in yields greater than 1 mt, the thermal radiation increases to 45% of the energy.

The warhead's yield is not the only part of the nuclear weapon you will have to consider in building your doomsday device. You also must decide how you are going to implement the equation E = mc2. You will have to choose a trigger device. The simplest, and original way, to set off an atomic bomb is the gun-triggered method. In this method, a projectile is fired at the appropriate moment into the sphere of radioactive material and a generator. This generator would send neutrons into the radioactive material, and the sudden increase in instability would cause the material to break apart, thus rendering fission! But that was an inefficient and crude style.

There is also the implosion-triggered detonation. In a bomb, surrounding the sphere of radioactive material there would be conventional explosives, packed into a tight space. Again, at the right moment, the explosives would be detonated and the resulting explosion would compress the sphere so tightly and suddenly that fission would ensue. Again, rather cheap and simple, yet crude. A more modern, refined version was later developed. The explosives would again go off, but this time they would send many cones of plutonium into a sphere of beryllium, setting off a fission reaction.

Fusion is the way to go for maximum efficiency and yield, but it also has it problems. In fusion weapons, often deuterium or tritium, is used, but they are both gases, which are hard to store, and have short half-lives. Also, both have to be highly compressed and stored at high temperatures in initiate the difficult process of fusion. However, these problems were overcome with the idea of placing a fusion bomb within a fission bomb. The neutrons from a fission bomb would not only produce X-rays that could provide the high temperatures needed, but also the neutrons released in fission could derive tritium from a lithium compound. That is how many nuclear warheads are designed nowadays. You can base your own design off of this, using different, more unstable elements, but you need to have a firm understanding of the periodic elements for that and I don't have the time to teach it right now.

Those silly Scandavians and their isomers...

Imagine a single gram of material that contains more energy than a quarter of a ton of TNT. Imagine this material requiring no fission of fusion to release this energy. Imagine this material being used in weapons a few decades from now.

That is the idea behind an isomer bomb, a gamma-ray bomb that can be used in any amount, from a suitcase with one tenth of a gram, to a ICBM with a warhead containing kilograms. Isomers are the high energy state of atoms, that will decay to lower energy states and release gamma radiation. Often, this process takes 31 to 546 years, but scientists learned how to trigger an artificial decay by bombarding a certain isomer, hafnium-178m2, with X-rays from a dentist X-ray machine. Remember what other process utilizes X-rays for detonation?

That's right, the fusion-within-a-fission bomb setup could be applied here. The price for the hafnium would be approximately the same as enriched uranium, but you can utilize any amount in a bomb, instead of the critical mass required for uranium to reach fission. In addition, though the gamma radiation would completely kill any living creature within range, their would be little direct fallout aside from the remaining, dispersed hafnium.

Sounds to perfect to be true? It may be. Many respected scientists, including ones in the employ of the Pentagon, have challenged the results of the Texas-based research team that produced the study proposing the above. The results have apparently not been reproduced in other laboratories; even using particle accelerators much stronger than a dental X-ray machine, this extra gamma radiation has not been produced outside of the University of Texas lab.

So the gamma-ray bomb is post-modern tech, if not far-future, for now.

For more information, press one or wait for the tone...

This wasn't as good as, say, a Clan Smoke Jaguar Guide, and perhaps I will add up more later. Specifically, exacts results for various yields of warheads, and what would happen to a city under a nuclear detonation. Anyways, if you really want the details, there is no better resource than:

http://www.fas.org/nuke/intro/nuke/7906/790604.pdf

And one day I will summarize:

http://www.fas.org/nuke/intro/nuke/7906/790606.pdf

Also, the math is at:

http://nuclearweaponarchive.org/Nwfaq/Nfaq5.html

And you can simulate a nuclear situations with this great program:

http://www.nukefix.org/weapon.html

Thanks for reading!

[Well, this doesn't take into account some of the more advanced forms of nuclear weapons, but it is a good beginner's guide to this. People are always bewildered when I inform them that even if they attack a tank or ship with a nuke, I'd retaliate and I've backed up my words with actions. Just ask Corrheia.]

Just ask Corrheia.

Will I be able to find them? This is an excellent piece of information. Consider it tagged.

[I limited the response to the airbase that launched the attack because there were allied troops in all of Corrheia's cities. Also, the nation itself isn't in the game anymore but it's being revived.]

OOC:Another thing that you might want to add, there are 2 kinds of targets when it comes to strategic nuclear war: Counterforce(attacking the enemies strategic missile silos, airbases, sub pens, and C3(Command, Control, Communication)) or Countervalue(Industrial Areas, transportation hubs, and Cities).

The advantage of targeting Counterforce targets is that you MIGHT be able to eliminate the enemies ability to counterattack, and if you have missiles left to target his Countercalue areas the enemy might just surrender(this is particularly effective if the enemy only uses bombers as his nuclear delivery system-and you have a VERY good Anti-Air system). The problem with a counterforce targets is if the enemy has even a half good ballistic missile detection network, you can garuntee that they will launch on warning right back at you.(unless you are using SLBMs only... but they still might be able to put 2 and 2 together in the 15 minutes it takes for a missile launched from a submarine to get to its target).

Using a counterval strategy has no pros... except ensuring the collapse of the enemies country. Since you wont be attacking the enemy silos/sub pens/airfields/combination of the three the enemy is open to reply. This is where MAD comes in.

Thanks for the input and responses.

Yes, I am aware this will be a very basic guide to some, but most do not realize exactly what a nuclear explosion consists of. Later I will be attaching more specific ways to design nuclear weapons. Heck, I'll do it now.

And thank you, Red Tide, I'll add that in too.

Updated and working on a section about designing nuclear weapons...

Really, really updated.

Tag, and even linked from my invision forum for some of the newbies in the two regions I host. GREAT JOB!

Thank you!

[OOC- Great guide, especially for new people. But I do have a few things to add.

One nukei sn't the end-all it's cracked up to be. Even if you drop a nuke directly in the middle of a major city, over 50% of the population of that city will still survive. However, that is corrected with the use of multiple nukes, in a lower kt range, detonated in a circle. This creates the most devestating aspect of a nuclear attack- the firestorm.

This is a combination of searing heat, flame, and high bursts of wind that create a wall of flame that will move towards the center of the blast due to air thrown out and burn anything there to cinders. The one at Hiroshima burned for hours and killed thousands that might not have died, due to its movement through outlying areas not hit as badly.

For an awesome program giving you all the info you'll ever need to know on nukes, read up about types of nuclear weapons, and see what happens when nukes are dropped, I strongly urge you to go to

http://www.nukefix.org/weapon.html

Thisi s the best source for any nuke info on the net that isn't too technincal but is technical enough to convey the image well enough. If you want to know anything at all about nukes, visit this site. Now.

But nice guide! Just add the results of detonation a bit more.]

This deserves an ubertag. Good job Lindim!!

Nice work, handy little guide for newbies.

The info about MAD is a particularly important thing for developing countries to remember :)

Thanks for the praise, and thank you to Samtonia. I know I need more details on the actual explosion over/in a city, but that's going to require a few more hours.

By tomorrow, though, I'll put your information in. If not tonight. And wow, that's a nice program!

[OOC-It is. It is one of the most in-depth things I have found detailing the uses, risks, and benefits of nuclear weapons. One scary thing is that it would require only about 700 Russian nukes(Avg. Range 400kt) to kill everything within an urban area with 1,000 people per square mile or more within the United States.

That's about 36% of the population in one attack. Scary.

But the best thing to do on the program is the "m" command. You can see the heat and estimated deaths of multiple silmultaneous airbursts in a circular pattern around a city. That's why multiple 20kt devices are far scarier then one 1 megaton device. Check that portion of the program out- it's simply amazing.]

Yes, I was looking at that. In this link (http://www.fas.org/nuke/intro/nuke/7906/790606.pdf) the writers describe the immediate, midterm, and long term efffects of several different attacks. I'm summarizing it right now...

I'll do a better update tomorrow.

And now I'm going to give you a little bit of information that every other nuclear weapons information page lacks.

One of the most, if not the most, advanced forms of modern tech nuclear weapons are isomer bombs. Basically speaking, an isomer is a form of a metal that holds a dispraportionate amount of energy within its molecules when compared to its atomic mass. One of the most stable isomers is also the most viable for nuclear weapons, Hafnium-178m2. The energy stored inside 1 kilogram of Hafnium is equal to a quarter kilotons of explosives and since Hafnium has a tendency to release all of its energy extremely quickly when excited into the appropirate state and does so in Gamma Rays, it should be apparent just what kind of potential nuclear isomers have as weapons of mass destruction.

To illustrate just how frightening these weapons are, I'm going to approach from a hypothetical position. Let us assume that a 2,000 JDAM had its warhead replaced with Hafnium and an x-ray triggering device. Furthermore, let's assume that trigger device requires 28 kilograms and we are left with four hundred kilograms for Hafnium. Suddenly what we have is a GPS-guided nuclear glide-bomb that has an explosive force worth 100 kilotons of TNT. Now, there are several advantages to using such a weapons when compared to more "conventional" nuclear weapons:

1) Isomer bombs leave behind less fallout that a coal factory.
2) Since all of the energy output is in gamma rays, there is no cascade radiation and no nuclear particles from reactors to prove who did it.
3) Indeed, there is very little proof that a nuclear attack occured at all, save that a city might suddenly disappear and a large crater left behind in its place.

I have never, ever read that before. Let me check it out before I post it, and thanks for the information.

Wow, just read an article on those things. I'll research some more and post a long addition on them.

They're scary.

Wow, nice one man! I'm linking this on my region's board too (if you don't mind:))

Wow, nice one man! I'm linking this on my region's board too (if you don't mind:))

Haha, be my guest! :D Thanks!

[OOC-Freaky SS. Freaky GOOD! Thanks a lot for the info. Oh, and Lindim, nice title for the area dealing with the fires. Very nice title indeed if I do say so myself. :)

Always nice to help educate NS.]

tag

Very good

Thanks, Kahta!

SS, I've done a little research of my own, and though I thank you for bringing the topic to my attention, I feel that you have missed something.

You portray isomer bombs as modern tech. Far from it. In fact, in a DoD report, the say that the technology to produce halfium in cost-effectively is years off, and decades before it can be used in a warhead.

The fact is, the halfium, while very powerful and revolutionary as the isomer bomb you showed, is simply to difficult to use practically at the moment, which is why I am not sure I want to add a section regarding it.

...

Nah, I'll mention it, it seems interesting and scary enough. Edit about isomers soon.

Nice work. This should be stickied.

Nice work. This should be stickied.

Thank you.

[Lindim, I hate to say it, but that report is willfully misrepresenting the position. The problem is that a bunch of scientists who believe they know everything there is to know about nuclear physics are calling into the doubt the existance of isomers, of course it's the same group of people who are currently having their faces rubbed in it over the Cold Fusion issue. The DoD being what it is, is taking the most conservative tack and doing so in a manner so as not to be called on it.

1) There is no "production" about it, Hafnium is used in pretty much every control rod in every reactor in the US and a good proportion of it comes out as the aforementioned isomer. Also, even at its most expensive it's cheaper by the pound than Uranium and Plutonium are by the ounce.

2) The "difficulty" in using is basically unwillingness to take nuclear research further than it has come so far. The only lab studying isomers at the moment is the same small one that originally made the discoveries, there's no money behind the research as of yet and probably won't be for some time as this is probably a rehash of the Cold Fusion incident.

There is a method using photons to excite isomers that has been postulated but not tested that should be considered post-modern tech, but the x-ray method has already been done and replicated several times using a simple dentist's x-ray machine.]

Rally? Wow, I'm surprised I never heard of it, and I subscribe to many American science magazines. This is very interesting, if you could send me a link I would be happy to fix the post. Thanks!

[Here's the link to the lab's page, they even have pictures of the set-up. It's nothing overly complicated and not geared for full power, but it proves the point.

http://www.utdallas.edu/research/quantum/ ]

[You made an error, I believe. A kilogram of Hafnium equals a quarter kiloton of TNT, you have a gram equaling 50 kilotons of TNT. IIRC, a gram of Hafnium equal about 50 kilograms of TNT. Other than that, yes I'm pleased.]

Let's continue this conversation in PM's on the OMP board. I don't want to spam this thread. :D

Okay, I've reposted the controversial Isomer Bomb section, which apparently is under heavy debate in scientific circles. For now, I will be skeptical, but I am open to other evidence.

There, updated.

OOOC: I've found a few interesting things I'd thought I share.

"Shaped" Nuclear Weapons. These actully can be made, but the process is classified by the American govement (these were developed with Project Orion, which is another interesting item to look at).

Clean bombs. These appear to be technically possibe;(so I've heard) but no nuclear physist will design one because it would be too dangerous if it fell into the wrong hands. And air burst fusion explosions are quite clean, so I've heard.

Clean bombs? As in, no fallout? I believe you might be referring to isomer bombs, which I have a section on. In theory, if they existed, they would have no fallout, but some respected scientists question the research behind the idea.

And yes, I've heard of shaped bombs, but I don't know much about them. Time to pull a few strings in the American DoD and gets some info. :)

Wait, are you referring to the bombs that bury underground before detonation? Yes, those do exist and most of the explosion would be contained underground, but it is physically impossible to direct the blast of a fission or fusion reaction, unless we had control of gravity.

Which we don't.

Wait, are you referring to the bombs that bury underground before detonation? Yes, those do exist and most of the explosion would be contained underground, but it is physically impossible to direct the blast of a fission or fusion reaction, unless we had control of gravity.

Which we don't.

Incorrect. It could in theory be done with magnetic fields.

I think they work by channeling most of the blast in a specific dierction, I guess that the bomb is incased in some sort of material (like a micro-orion, thats what I've heard they were developed for). I supposed that they would be useful for a commando attack...

[Well, I can only offer this; quantum mechanics is a balance, the ultimate expression of Yin and Yang. While scientists haven't figured out every little secret of quantum mechanics, nearly everything is possible when harnessing the power of the universe after all. If, in using our limited understanding of the universe and its mechanics, we can postulate that something can be done given Material A in Condition B to come up with Result C, then it is almost certainly so.

Also, I'd like to note that none of the attempts to replicate the results of the original experiment have suceeded for one very good reason, they didn't mirror the scientific process originally used.]

Oh dear, I have to clear up some pseudoscience here. Okay, the whole idea of magnetic lines "crossing" and setting up a huge, massive explosion was proposed and then immediately debunked in the 1950's. I have a Popular Science from 1953 that mentions it. Magnetic lines don't cross, they don't even exist. They're just drawings to give an impression of a magnetic field.

Second of all, if you can name a material or something that can be built into a warhead that can channel the blast of a nuclear explosion, you should win a Nobel Prize. Because that's impossible in modern physics.

And SS, many respected scientists disagree, and yes I know they could all be wrong, but I will be taking the skeptical side for now on isomer bombs. It seems plausible, though.

Anyways, please, I hate saying this, but please keep the pseudoscience, and it is, out of this thread. Thanks.

On another note, Buy Me Magical Ponies, and BUMP it!

[And I tend to take a skeptical tack of any "respected" scientist who says something can't be done. Those are the same kind of people who have been proven wrong after they said Cold Fusion wasn't possible.]

Cold fusion is not at a state where it has acquired breakeven energy.

On another note, BUMP for those who still would like some understanding of nuclear weapons, and why there are not used in the real world.

Incorrect. It could in theory be done with magnetic fields.

Except that we do not have such mastery of magentic fields to really do that yet.

Cold fusion is not at a state where it has acquired breakeven energy.

On another note, BUMP for those who still would like some understanding of nuclear weapons, and why there are not used in the real world.

[True. But it's also true that's also so for fusion as well. My point was that scientists have stated that it isn't possible. Full stop.]

Noted, and thus this conversation dies.

Meanwhile, I am working on a Tentative Guide to Biological and Chemical Weapons.

Anyways, please, I hate saying this, but please keep the pseudoscience, and it is, out of this thread. Thanks.

Woah, I'm just reporting on what I heard. I am not a follower of pseudoscience...

I have become death, the shatterer of worlds. I wait for the hour that ripens to their doom - The Bhagavad Gita, uttered by Doctor Robert Oppenheimer, Diector: Los Alamos/Manhatten Projects

I have become death, the shatterer of worlds. I wait for the hour that ripens to their doom - The Bhagavad Gita, uttered by Doctor Robert Oppenheimer, Diector: Los Alamos/Manhatten Projects

Nice. Bonus points for spotting the double reference in that. ;)

Woah, I'm just reporting on what I heard. I am not a follower of pseudoscience...

Sorry if that seemed mean, I just didn't want this thread to get hijacked by stuff like that. Pseudoscience is just one of those things that annoy me.

Sorry if that seemed mean, I just didn't want this thread to get hijacked by stuff like that. Pseudoscience is just one of those things that annoy me.
Ah, okay. Psudoscience also annoys me. But I shant hijack this thread any longer.

Nice. Bonus points for spotting the double reference in that. ;)

Why thank you. I always liked that quote, its on the front of one of my school binders.

Why thank you. I always liked that quote, its on the front of one of my school binders.

I think Oppenheimer did summarize nuclear weapons with unmatched eloquence in that quote. Though I find the translation "I am become death, the destroyer of worlds..." more poetic.

Bump. I forgot the link, so I'm tagging this (again) for simplicity. Bueatiful (spelling?) post, And I'm remembering to link this this time! LOL The n00bs on my forum will love this. (they'll get to explain in detail what happens when they glass each other in our "internal incedents" forum)

Bump. I forgot the link, so I'm tagging this (again) for simplicity. Bueatiful (spelling?) post, And I'm remembering to link this this time! LOL The n00bs on my forum will love this. (they'll get to explain in detail what happens when they glass each other in our "internal incedents" forum)

Thanks. Haha, yes, for their pleasure I am also working on not only a detailed description of the short and long term effects of nuclear attacks on cities, but I am also developing a biological weapons guide too.

Thanks again for the tag!

[I hope it's a biochem guide. I'm more prone to using chemical weapons than I am nuclear, yet I know more about nuclear weapons and everything their use entails, so having a good guide to biochem weapons would be nice.

Nice work. Deserving of a Sticky.

Nice work. Deserving of a Sticky.

Whee, thanks! Tell that to the mods. :D

Biological Weapons Guide is coming along nicely, and will be better than this guide. Also, it is harder to write it, much more information.

OOC: Bump, while I laze about doing nothing.

A slight bump. I don't think this is gravedigging, from only four days ago.

If it is, I apologize.

bookmarked.

A good guide.

There is one thing to add though - the difference between Plutonium and an Uranium bomb, and the problems with developing either.

The main problem with atomic bomb design is how to force most of the fissioning material to actually partake in the chain reaction. When the reaction starts, in the first bombs it has scattered most of the fissionable material even before they could do.

Uranium has a nice quality - namely it won't spontaniously start a chain reaction, you need a trigger (a neutron source). This makes bomb design immensly easier.
Plutonium on the other hand will immediately start the rection once critical mass is availible.

Another thing must be said about critical mass as well: it's not just mass. It's a critical ammount of mass in a critical volume of space.
What it boils down to is that neutron density from fissioning atoms have to reach a point where it will counter both scattering (neutron going outside) and absorption (sometimes a corewill take in a neutron without splitting).

As I said, a Uranium bomb in actual structure is relativly simple.
However Uranium has two isotopes U-235 and U-238. The problem is that U-238 the heavier and more abundant of the isotopes absorbs neutrons turning into Pu-239 without splitting.
To make a bomb we need enriched uranium, a quite enriched: weapons grade uraiun is 95% U-235. The challenge of enrichement is that both isotopes behave chemicaly same way, so we need to use physical attributes to separate them. This attribute is that U-238 is just a tad heavier.
Therefore enrichment is very-very expensive. Let me demonstrate is further: the centrifuge facilities that supplied 1/3 of the uranium for the test bomb in the desert and Hiroshima took all the silver stockpiles of the USA at the time. (The only gas compound of uranium that's gaseous at room temperatures is Uranium Hexafluorid an immensly corrosive molecule, therefore corrosion resistant materials - like silver - had to be used.)

So although an Uranium bomb is easier to make, producing the necessary enriched uranium is very expensive and will take a lot of time. (4-5 years at the least) for each bomb.

Plutonium though is easier to manufacture. Actually all nuclear powerplants produce it. This is the reason why nuclear bomb and powerplant research was going on simultaniously.
A nuclear powerplant only needs and enrichment rate of 3% or none at all if you're willing to use heavy water in the reator.
With enough plants you can produce enough Plutonium for a hefty nuclear arsenal.

The difficulty in this case comes from the actual constuction of the bomb.
When critical mass is achieved Plutonium will spontaniously start a chain reaction and the fissionable matter will throw itself apart wasting most of the Plutonium....and won't be even as effective as a Uranium bomb.
So we need to counteract the explosive force and keep it all together util more of the Plutonium partook in the reation: This lead to the development of the implosion bomb.
It is an extremely complicated process though, and the mathematics behind the design was among the prime motivations for the development of powerful electronic computers.