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The fusion process in the Tokamak generates a high pressure gradient using magnetic fields. The Plasmareactor utilises the Z-pinch effect to compress the plasma, which generates a high pressure gradient. This is a 10 times more efficient method of producing sufficient magnetic fields to compress plasma and generate heat for fusion energy.
The difference in extracting energy from the fusion process is due to the magnetic nature of a Tokamak. The Tokamak utilises a magnetic bottle to contain the plasma (which has same net charge as an atom). This means that any charged particle coming from the fusion process will be trapped by this magnetic bottle and pass several time through the hot plasma before escaping into space. This means that a huge load of heat need to be dissipated from the metal walls of the Tokamak, whilst energy is extracted from this heat.
In contrast, since there is no trapped charge in the Plasmareactor (all charges are equal and opposite), there are no magnets involved in extracting energy from this system; it’s as simple as collecting charged particles in an exhaust pipe with small holes in it – all particles entering these holes are collected with huge efficiency inside your exhaust pipe!
The tokamak uses the toroidal pressure gradient. In the plasmareactor, energy is extracted by scanning a beam of electrons across the plasma and using this to heat a liquid metal. The liquid metal is subsequently used to drive steam turbines.
The advantage of the plasmareactor over conventional designs is that it allows a greater percentage of energy extracted from the plasma, due to its greater efficiency. This means more energy per unit volume, which means less fuel consumption. There are also other potential benefits, but I won't go into that right now.
The disadvantages include the complexity of the design and the potential for instabilities in the plasma which can lead to uncontrolled reactions and release of energy. The plasmareactor also requires a much higher power input than conventional designs, which means it is currently only feasible as a research tool.
The Plasmareactor is magnetic compression of plasma to generate energy, this being in the form of electrons or photons.
The principle behind the Plasma reactor is the utilisation of the Z-pinch effect on a toroidal plasma body. A plasma toroid can be formed by injecting a stream of energetic particles along an axis perpendicular to a magnetic field, in effect creating a current through the axial field
The Z-pinch effect is when this current and resultant magnetic field causes contraction of the plasma itself along its axis. This results in a high pressure region and can cause instability, but with proper control can be used to generate stable high pressures. In addition to this, if the Z-pinch is on an axis that isn't perpendicular to an external magnetic field, then we get an additional Lorentz force acting on the plasma as well as an additional contraction force. This gives us added control over the pressure and stability of our plasma toroid.
The advantage of using a poloidal rather than toroidal configuration for our pinch is that it has much better confinement properties. A toroidal pinch will tend to expand outwards due to its shape, whereas a poloidal pinch will be confined by the external magnetic field. This gives us two benefits: firstly, it means that we don't need such a high current to maintain our pinch; and secondly, it means that we can use a weaker external magnetic field, which reduces the amount of energy required to create it.
The main difference between this and Tokamak fusion reactors is in how energy is extracted from the system. In Tokamaks, energy is extracted by heating a working fluid (usually water) which then drives turbines. In the Plasma reactor, energy is extracted directly from the plasma itself. This can be done in two ways: either by extracting electrons from the plasma and using them to drive an electric current; or by extracting photons from the plasma and using them to drive a photovoltaic cell. Both of these methods have advantages and disadvantages; for example, extracting electrons requires a strong magnetic field, which increases the energy requirements; while extracting photons requires cooling of the plasma (to prevent it from re-absorbing the photons), which increases the complexity of the system. Ultimately, it will be up to engineers to decide which method is best for any given application.
In this case we will be using the same pressure gradient, however the steam is to be replaced with plasma, which should be able to provide a constant flux and a larger pressure gradient.
This is identical to the bread and butter solenoid of a Tokamak, expect that the heating element uses plasma instead of steam. In this example the plasma will be electrically heated by an external source. This is not necessary, but it increases efficiency as less energy is used to maintain temperature.
This is a very basic model of what I would like my fusion reactor to look like. I'm not entirely sure if this would work for reasons I shall list below.
I have attempted various types of research on how the Z-pinch effect works, but I have been unable to find any specific papers on what kind of filamentary shapes are necessary for the pinch effect to occur? Can it occur in all shapes or only certain ones? For example can it occur in a spiral shape or are filaments always deployed in linear fashion?
Are there any other ways that one can reduce or increase pressure gradients within plasma besides utilising Z-pinches?
A:
The Z-pinch effect was first demonstrated with round wires and since then has been further developed with flat tapes (known as "high aspect ratio z-pinches"). The filamentary shape does not matter much for the pinch effect itself, but more for other aspects such as thermal radiation losses. In principle though you can use any geometry you want, although Z-pinches are most commonly seen with cylindrical geometries.
The plasma reactor uses a second plasma toroid which is used to draw energy from the reaction chamber. The energy is extracted by the use of a magnetic field, and in this case the pressure gradient is used to drive 6 symmetrically placed steam turbines.
The poloidal Z-pinch axis was chosen because it offers a much more stable configuration than one on the rotational axis. In addition, during confinement, atmospheric pressure pushes down on the reaction chamber, as opposed to pulling up on it in a rotational design. This greatly improves safety and control of the system.
The secondary plasma toroid is used for two purposes; one to extract heat from the reaction chamber using MHD (magneto hydro dynamic) principles, and two to create an artificial gravity field which adds extra confinement to the fusion products so that they are forced back into the reaction chamber. This will allow for much lower power consumption than other types of fusion reactors as well as creating a safe system which can be used for power generation and space propulsion.
The Z-pinch technology was originally designed to compress a plasma and trigger a fusion reaction. An explanation of the process in the context of the plasmareactor is given. The purpose of the Z-pinch is to compress the poloidal plasma column, causing it to heat up and expel energy as radiation. This radiation is then captured by an array of parabolic mirrors surrounding the column, which reflect it through a hole in the reactor chamber. The mirrors are angled so that they focus the radiation on a turbine, which drives a generator. The generator produces electricity and powers an electromagnetic coil that wraps around the plasma column. This coil keeps the plasma column from moving out of position and maintains its shape.
A key advantage that Z-Pinch has over other magnetic confinement fusion schemes, such as Tokamaks, is that it can be much smaller in scale (see video below). Two different versions of plasmareactor have been proposed: one uses hydrogen as its fuel, while the other uses deuterium. Hydrogen has a number of advantages over deuterium: it is cheaper and more abundant, and it produces less radioactive waste. However, hydrogen is also more difficult to confine than deuterium, so the plasmareactor will need to be larger if it is to use hydrogen as its fuel. The plasmareactor will also need to be larger if it is to produce more than 1 gigawatt of power; 1 gigawatt is enough to power about 1 million homes.
How big does a plasmareactor need to be? This depends on several factors, such as the type of fuel it uses and the amount of power it produces. For example, if the plasmareactor uses hydrogen as its fuel and produces 1 gigawatt of power, it will need to be about 100 meters in diameter. If it uses deuterium as its fuel and produces 1 gigawatt of power, it will only need to be about 50 meters in diameter.
The plasmareactor will also need to be surrounded by a containment structure to prevent the escape of radiation. The size of this containment structure will depend on the size of the plasmareactor and the amount of power it produces. For example, if the plasmareactor is 100 meters in diameter and produces 1 gigawatt of power, the containment structure will need to be about 200 meters in diameter.
The cost of building a plasmareactor will depend on its size and complexity. For example, if the plasmareactor is 100 meters in diameter and produces 1 gigawatt of power, it will cost about $10 billion to build. This is much cheaper than other fusion reactors that have been proposed, such as Tokamaks, which can cost upwards of $50 billion to build.
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