Why is a stellarator twisted?

By twisting one end of the torus compared to the other, forming a figure-8 layout instead of a circle, the magnetic lines no longer travelled around the tube at a constant radius, instead they moved closer and further from the torus' center.

Why are tokamaks donut shaped?

If you've heard of fusion energy, you've probably heard of tokamaks. These doughnut-shaped devices are meant to cage ionized gases called plasmas in magnetic fields while heating them to the outlandish temperatures needed for hydrogen nuclei to fuse.

How does a stellarator work?

A stellarator is a machine that uses magnetic fields to confine plasma in the shape of a donut, called a torus. These magnetic fields allow scientists to control the plasma particles and create the right conditions for fusion reactions.

What is the difference between tokamak and stellarator?

In the tokamak, the rotational transform of a helical magnetic field is formed by a toroidal field generated by external coils together with a poloidal field generated by the plasma current. In the stellarator, the twisting field is produced entirely by external non-axisymmetric coils.

How does a tokamak work?

In a tokamak, magnetic field coils confine plasma particles to allow the plasma to achieve the conditions necessary for fusion. One set of magnetic coils generates an intense “toroidal” field, directed the long way around the torus.

Fusion Research Lecture #02 - Twisted magnetic field, Stellarator

Can a tokamak explode?

During operation, the ITER Tokamak chamber will contain only a tiny amount, less than one tenth of a gram, of hydrogen fuel at any given moment. If disruption occurs during a pulse, the reaction cools and ends. "A nuclear explosion in ITER is simply not possible," says Loughlin.

How does a tokamak not melt?

Fusion powers the sun by forcing hydrogen atoms to combine into helium and releasing enormous amounts of energy. A tokamak uses strong magnetic fields to confine a plasma that is heated above 200 million ℃, maximizing the efficiency of hydrogen isotope fusion.

Why is it called a tokamak?

The term "tokamak" comes to us from a Russian acronym that stands for "toroidal chamber with magnetic coils" (тороидальная камера с магнитными катушками). To start the process, air and impurities are first evacuated from the vacuum chamber.

What is stellarator physics?

A stellarator is a plasma device that relies primarily on external magnets to confine a plasma. Scientists researching magnetic confinement fusion aim to use stellarator devices as a vessel for nuclear fusion reactions. The name refers to the possibility of harnessing the power source of the stars, such as the Sun.

How does a spheromak work?

The Spheromak inherits toroidal field from the gun field and poloidal field from the stuffing field (d). The process is analogous to blowing a soap bubble. The soap film tension represents the stuffing field strength and the pressure of one's breath represents the magnetic pressure of the gun current.

How much does a stellarator cost?

The total investment for the stellarator itself over 1997–2014 amounted to €370 million, while the total cost for the IPP site in Greifswald including investment plus operating costs (personnel and material resources) amounted to €1.06 billion for that 18-year period.

How does Z-pinch reactor work?

The Z-pinch configuration offers the promise of a compact fusion device owing to its simple geometry, unity beta, and absence of external magnetic field coils. Increasing the axial current compresses the plasma, resulting in a rapid rise of the fusion reaction rate.

Can cold fusion work?

These retractions, combined with negative results from some famous laboratories, led most scientists to conclude, as early as 1989, that no positive result should be attributed to cold fusion.

What does tokamak mean in Russian?

A tokamak (/ˈtoʊkəmæk/; Russian: токамáк) is a device which uses a powerful magnetic field to confine plasma in the shape of a torus. The tokamak is one of several types of magnetic confinement devices being developed to produce controlled thermonuclear fusion power.

Is nuclear power limitless?

If nuclear fusion can be successfully recreated on Earth it holds out the potential of virtually unlimited supplies of low-carbon, low-radiation energy. The experiments produced 59 megajoules of energy over five seconds (11 megawatts of power). This is more than double what was achieved in similar tests back in 1997.

What does ITER stand for?

Iter, which stands for International Thermonuclear Experimental Reactor, is a major international project to build a 500MW tokamak fusion device (requiring an input of 50MW) designed to prove the feasibility of fusion as a large-scale and carbon-free source of energy.

What is the shape of an ideal toroid?

(a) A toroid is a coil wound into a donut-shaped object.

How does inertial confinement fusion work?

In an inertial confinement fusion (ICF) reactor, a tiny solid pellet of fuel—such as deuterium-tritium (D-T)—would be compressed to tremendous density and temperature so that fusion power is produced in the few nanoseconds before the pellet blows apart.

How does a magnetic mirror work?

Magnetic Mirror. A magnetic mirror is a static magnetic field that, within a localized region, has a shape such that approaching charged particles are repelled back along their path of approach. A magnetic field is usually described as a distribution of nearly parallel nonintersecting field lines.

How hot do tokamaks get?

The temperatures inside the ITER Tokamak must reach 150 million degrees Celsius—or ten times the temperature at the core of the Sun—in order for the gas in the vacuum chamber to reach the plasma state and for the fusion reaction to occur.

What fuel does tokamak use?

Once the fusion reaction is established in a tokamak, deuterium and lithium are the external fuels required to sustain it. Both of these fuels are readily available.

Why is there no fusion power?

One of the biggest reasons why we haven't been able to harness power from fusion is that its energy requirements are unbelievably, terribly high. In order for fusion to occur, you need a temperature of at least 100,000,000 degrees Celsius. That's slightly more than 6 times the temperature of the Sun's core.

What is hotter than the Sun?

And the answer: lightning. According to NASA, lightning is four times hotter than the surface of the sun. The air around a stroke of lightning can peak at 50,000 degrees Fahrenheit, while the surface of the sun is around 11,000 degrees. Meanwhile, magma can reach temperatures near 2,100 degrees.

How hot is the plasma in a fusion reactor?

In a nuclear fusion reactor, the hot, charged gas known as plasma reaches out of this world temperatures at 150 million degrees Celsius, or 10 times hotter than the center of the sun.