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How a fusion bomb might work without a fission bomb Also shows how to construct fusion bombs which can be used with or without fission bombs.



Two example of real fusion bombs that use fission to set them off.
Basic fusion bomb1. Example1
Basic fusion bomb2. Example2



Teller-Ulam Design of a Fusion Bomb
To understand this bomb design, imagine that within a bomb casing you have an implosion fission bomb and a cylinder casing of uranium-238 (tamper). Within the tamper is the lithium deuteride (fuel) and a hollow rod of plutonium-239 in the center of the cylinder. Separating the cylinder from the implosion bomb is a shield of uranium-238 and plastic foam that fills the remaining spaces in the bomb casing. Detonation of the bomb caused the following sequence of events:

The fission bomb imploded, giving off X-rays.
These X-rays heated the interior of the bomb and the tamper; the shield prevented premature detonation of the fuel.
The heat caused the tamper to expand and burn away, exerting pressure inward against the lithium deuterate.
The lithium deuterate was squeezed by about 30-fold.
The compression shock waves initiated fission in the plutonium rod.
The fissioning rod gave off radiation, heat and neutrons.
The neutrons went into the lithium deuterate, combined with the lithium and made tritium.
The combination of high temperature and pressure were sufficient for tritium-deuterium and deuterium-deuterium fusion reactions to occur, producing more heat, radiation and neutrons.
The neutrons from the fusion reactions induced fission in the uranium-238 pieces from the tamper and shield.
Fission of the tamper and shield pieces produced even more radiation and heat.
The bomb exploded.

All of these events happened in about 600 billionths of a second (550 billionths of a second for the fission bomb implosion, 50 billionths of a second for the fusion events). The result was an immense explosion that was more than 700 times greater than the Little Boy explosion: It had a 10,000-kiloton yield

How a common fusion bomb works:

A fission weapon (the "primary") is placed at one end of the warhead casing. When detonated, it first releases X-rays at the speed of light. These are reflected from the casing walls, which are made of heavy metals and serve as X-ray mirrors. The X-rays travel into a space surrounding the secondary, which is a column or sphere of lithium deuteride fusion fuel encased by a natural uranium "tamper"/"pusher". Here, the X-rays cause a pentane-impregnated polystyrene foam filling the case to convert into a plasma, and the X-rays cause ablation of the surface of the jacket surrounding the secondary, imploding it with enormous force. Inside the secondary is a "sparkplug" of either enriched uranium or plutonium, which is caused to fission by the compression, and begins its own nuclear explosion. Compression of the fusion fuel and the high temperature caused by the fission explosion cause the deuterium to fuse into helium and emit copious neutrons. The neutrons transmute the lithium to tritium, which then also fuses and emits large amounts of gamma rays and more neutrons. The excess neutrons then cause the natural uranium in the "tamper", "pusher", case and x-ray mirrors to undergo fission as well, adding more power to the yield. This last effect can greatly increase both the yield of the device and the amount of fission-related fallout. Non-fissionable materials (lead, tungsten, etc.) can be used in the tamper/pusher and case instead of fissionable ones (uranium or thorium), reducing the yield and the fallout accordingly.

Others have questioned the "foam" mechanism of radiation implosion described above, and instead indicated that the actual mechanism that compresses the secondary stage is neither the "radiation pressure" of the x-rays, nor the physical pressure of the plasmatized foam, but suggest rather that only the x-ray radiation 'burning' the outside surface of the tamper/pusher away. X-rays surround and heat the whole outside of the tamper/pusher until the outside layer of it ablates/explodes away from the secondary in all directions, creating an inward "ablation pressure." In other words, heated by x-rays, the outside layers of the tamper/pusher explode outward, like a rocket, driving the remaining layers inward in an implosion. Modern nuclear weapons probably use fusion stages that are spherical, rather than cylindrical. [3]

Information on the two most required parts of a fusion bomb:

1. Tamper reflector

A tamper is an optional layer of dense material (typically natural or depleted uranium or tungsten) surrounding the fissile material. It reduces the critical mass and increases the efficiency by its inertia which delays the expansion of the reacting material.
The tamper prolongs the very short time the material holds together under the extreme pressures of the explosion, and thereby increases the efficiency, i.e. the fraction of the fissile material that actually fissions. The high density has more effect on that than high tensile strength. Fortunately for the weapon designer, materials of high density tend to be good reflectors of neutrons.
While the effect of a tamper is to increase the efficiency both by reflecting neutrons and by delaying the expansion of the core, the effect on the efficiency is not as great as the effect on the critical mass. The reason for this is that the process of reflection is relatively time consuming and may not occur extensively before the chain reaction is terminated.

2. Neutron reflector

A neutron reflector layer is an optional layer commonly found as the closest layer surrounding the fissile material. This may be the same material used in the tamper, or a separate material. While many tamper materials are adequate reflectors, the best reflector (beryllium metal) makes an extremely poor tamper.
The most efficient reflector is believed to be beryllium metal, then beryllium oxide and tungsten carbide roughly equally efficient, then uranium, then tungsten, then copper, then water, then graphite and iron which are roughly equally efficient. [2] There is a design tradeoff in choosing to employ a tamper, reflector, or combined material. The weight of the combined pit assembly (any pusher, tamper, reflector, and the fissile material all together) has to be accelerated inwards by the implosion assembly explosives. The larger the pit assembly, the more explosives are needed to implode it to a given velocity and pressure. Early implosion nuclear weapons used heavy pushers and tampers, which were moderately effective reflectors (natural uranium tampers, for example). Levitated or hollow pits increase the energy efficiency of implosion. Using highly efficient, lightweight reflectors made of beryllium further increases the mass efficiency of the implosion system. Such pits are only slightly tamped, and will dissassemble very rapidly once the fission reaction reaches high energy levels. Before fusion boosting, it was arguable whether the most efficient overall system employed dedicated high mass tampers or not. Now that modern weapons typically use fusion boosting, which increases the reaction rate tremendously, lack of tamper material is no longer a drawback. This has helped allow for the miniaturization of nuclear weapon systems.


Other stuff for defensive weapons program for peaceful purposes.


Ways to heat a plasma.

1. Ohmic Heating - The plasma can be heated to temperatures up to 20-30 million K through the current passing through the plasma. It is called ohmic or resistive heating; the heat generated depends on the resistance between the plasma and current. However, as temperature rises, resistance drops, making this form of heating less and less effective. Other methods are neccessary in addition in order to heat the plasma to required temperatures.

2. Neutral-Beam Injector - High energy, neutral atoms are shot into the plasma, and are immediately ionized. These ions then get trapped by the magnetic fields, and transfer some of their energy to the surrounding plasma particles through collisions, thus raising the overall temperature. Author side note: THE FOCUS FUSION REACTOR IS GREAT FOR THIS. USE ITS PARTICLES TO HEAT A SECONDARY PLASMA!!!

3. Magnetic Compression - The plasma can be heated through a rapid compression, which is possible by increasing the magnetic field. In the tokamak, this compression occurs by moving the plasma to an area of a higher magnetic field.

4. Radiofrequency Heating - High-frequency waves are launched into the plasma through the use of oscillators. If the waves have the right wavelength, their energy can be transferred into certain particles, which then transfer the energy through collisions with others.


Basic homemade plasma heater.Heating up a plasma.


Basic fusion reactor Heating up a plasma.


Plasma containment. Shows how to confine a plasma.


How to build a neutron initiator How some triggers for nuclear weapons are made.


Homemade breeder reactor Build a homemade breeder reactor and take a free ride in a police car. (Not recommended for building but it has been done.)


How to make elements or matter. Pretty much a overall review of making atomic matter. Not practical but good if your SOL(*?&! out of luck). For those hard to get items.


Building particle or ion guns. These come in handy sometimes. Can be used to transmute elements.


Making matter misc. parts. Stuff you might need to make matter.


How to transmute elements Good for those hard to get items. Shows how to make some things you might need.


How to seperate isotopes(Example: hydrogen and oxygen are isotopes of water(H20). Again, also good for those hard to get items.


Making radiation Ok, lets make some homemade radiation. (X-rays or Gamma rays).


How Chemical compounds are made. How some nuclear fuels are made.


Space program Every nuclear research program for peaceful purposes for some unknown reason has to have a space program. Go figure. Here you go. (HIGHLY EXPERIMENTAL UFO STUFF)


Weapons Every nuclear research program for peaceful purposes needs weapons to protect the research. (Here you go.)


How to make parts for your reactor or peaceful nuclear research projects. This is called a home foundry. Simple way to make metal parts or build an entire machine shop from scrap metal, sand, and a little bit of wood. With books from Lindsay publications and a good computer and software there is no limit to what you can do.



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