Disclosed herein is a stellarator comprising two sets of coils, namely a set of encircling coils which encircle the plasma axis, and a set of shaping coils which do not encircle any other coil or the plasma. In some embodiments, the encircling coils include a structural element to maintain their shape under magnetic forces. In some embodiments, the shaping coils are mounted onto one or more structural elements which, together with the shaping coils, constitute a field shaping unit. Also disclosed is a controller which may modify the electrical current flowing in one or more subsets of the coils in order to achieve target plasma parameters. Also disclosed is a method of designing a set of shaping coils by discretizing a surface dipole or current potential distribution.

The present disclosure provides methods for defining a magnet array for a stellarator. In some embodiments, the magnet array, once defined, comprises a plurality of permanent magnets, where each permanent magnet of the plurality of permanent magnets is selected from a set of predetermined permanent magnet types. In some embodiments, each predetermined permanent magnet type in the set of predetermined permanent magnet types has a predetermined shape (geometry) and/or predetermined orientation angles (also known as a polarization orientation).

Disclosed herein is a stellarator comprising two sets of coils, namely a set of encircling coils which encircle the plasma axis, and a set of shaping coils which do not encircle any other coil or the plasma. In some embodiments, the encircling coils include a structural element to maintain their shape under magnetic forces. In some embodiments, the shaping coils are mounted onto one or more structural elements which, together with the shaping coils, constitute a field shaping unit. Also disclosed is a controller which may modify the electrical current flowing in one or more subsets of the coils in order to achieve target plasma parameters. Also disclosed is a method of designing a set of shaping coils by discretizing a surface dipole or current potential distribution.

The present disclosure may provide methods and systems for exhausting particles from a plasma field using, at least in part, the backside surface of a divertor.

The present disclosure is directed to stellarators or assemblies including a stellarator including removable and/or replaceable components, such as removable field shaping units and/or removable shaping coils. In some embodiments, the stellarators of the present disclosure include a toroidal sector, which includes one or more removable field shaping units.

All magnetic nuclear fusion devices face common technical challenges related to power and particle control arising from the close proximity of a thermonuclear plasma to the plasma-facing component. The plasma-facing component is subjected to high incident power density and erosion processes, and must facilitate the efficient remove of the fusion-ash. In the past, limiters and divertors have been used in magnetic fusion devices for this purpose. These are discussed and extended to a new concept, the stochastic mantle, which utilizes a stochastic magnetic field layer to disperse power on the plasma-facing component to the maximum extent possible. Further, if operated at sufficient plasma collisionality, it reduces the energy of particles incident on the plasma-facing component, globally reducing erosion by physical sputtering, while producing high gas pressures for fusion-ash removal through pumping ducts. The approach is particular suited for stellarators, but others devices may be considered.

The present disclosure relates to an assembly comprising a plurality of modular coils (100a, 100b; 401) mechanically and electrically joined together, wherein each modular coil comprises a groove (110a, 110b) separating the modular coil into at least two different electrically conducting regions.

Disclosed are techniques for initiating and sustaining a transport barrier within a magnetically confined plasma in a plasma fusion device. For a toroidal magnetic configuration, a characteristic region of the magnetic field can be established by generating a current within the plasma or by other means. The location of the characteristic region can be controlled to be suitably close to the interior walls of the plasma fusion device to allow a quantity of particles to be injected into the plasma at or inside the characteristic region. The quantity of particles can augment the density of the plasma and create a density gradient within the characteristic region, resulting in the formation of a transport barrier at or inside the characteristic region.

A method of joining a first substrate and a second substrate to thereby form a joint. A stack is provided, including filler material and a plurality of retention mediums, between the first and second substrate. The stack is heated to melt the filler material and to wet the first and second substrate with melted filler material. Said melted filler material is allowed to solidify to form the joint.

The present disclosure is directed to stellarators or assemblies including a stellarator including removable and/or replaceable components, such as removable field shaping units and/or removable shaping coils. In some embodiments, the stellarators of the present disclosure include a toroidal sector, which includes one or more removable field shaping units.