Some examples herein provide a method for generating a magnetic field. The method may include accumulating positive charges at a first electrode; accumulating negative charges at a second electrode; and rotating the first electrode relative to the second electrode so as to induce a relative angular velocity between the positive charges and the negative charges and thus generate a magnetic field. In some examples, the magnetic field may be used for propulsion.

A transfer type contra-rotating geomagnetic energy storage-release delivery system is disclosed. The system includes a control system, a three-axis control moment canceller and an energy system, which are arranged on a delivery mother spacecraft, and the delivery mother spacecraft is connected, through support rod structures, with a strong magnetic moment generating device, a contra-rotating transmission mechanism and two delivery connection rod structures arranged at the two ends of the contra-rotating transmission mechanism, the strong magnetic moment generating device is arranged between the contra-rotating transmission mechanism and the delivery mother spacecraft, the two delivery connection rod structures are provided with slidable mass blocks respectively, and the strong magnetic moment generating device and the contra-rotating transmission mechanism provide energy through the energy system. The strong magnetic moment generating device is free of accelerated rotation of an attitude, thereby decoupling the dual coupling.

Provided is a variable energy and miniaturized accelerator. It is impossible to change the energy of the extraction beam in the related cyclotron or to miniaturize an accelerator in the related synchrotron. The accelerator includes a pair of magnets which form a magnetic field therebetween; an ion source which injects ions between the magnets; an acceleration electrode which accelerates the ions; and a beam extraction path which extracts the ions to the outside. A plurality of ring-shaped beam closed orbits formed by the pair of magnets, in which the ions of different energies respectively circulate, are aggregated on one side. The frequency of the radiofrequency electric field fed to the ions by the acceleration electrode is modulated by the beam closed orbits.

A method of designing at least one coil for producing a magnetic field is disclosed. The method comprises: i) setting a performance target comprising: a target magnetic field, and at least two of a target power, a target resistance, a target size and/or weight, a target supply voltage or current, and a target inductance; ii) determining initial design parameters for the at least one coil; iii) modelling performance with the current design parameters to determine a simulated performance against each of the performance targets; iv) calculating a penalty function based on the difference between the simulated performance and the performance targets; v) modifying the design parameters in order to reduce the penalty function; vi) iterating steps iii) to v) until the penalty function or simulated performance has met an acceptance condition.

The present disclosure provides a stellarator magnet based on cubic permanent magnet blocks and an arrangement optimization method thereof. For the characteristic that a three-dimensional magnet coil of a stellarator is complex in structure, the present disclosure provides the stellarator magnet based on the cubic permanent magnet blocks with uniform magnetization, same magnetization and same size; the magnetization directions of the cubic permanent magnet blocks are defined in a limited number of fixed alternative directions; the magnetic field configuration of the stellarator is generated by dipole magnetic fields provided by the permanent magnet blocks and planar coils, so that the device complexity of the stellarator is reduced, and the difficulty and cost of the machining and installation of the magnet are reduced. The shape of the permanent magnet blocks can be replaced by other regular shapes, and the permanent magnet is still formed by the permanent magnet blocks with same shape, same size, uniform magnetization and same magnetization. For the magnet, the present disclosure provides a magnet arrangement optimization method of ‘local compensation’ and related optimization strategies of ‘threshold truncation,’ ‘global fine tuning,’ etc., for meeting different optimization requirements on accuracy of the magnetic fields, usage qualities of magnets, etc., and a magnetic field meeting designing requirements can be obtained.

An electron paramagnetic resonance (EPR) spectrometer includes a magnet system comprising at least one magnet and at least one pole piece for producing a magnetic field along a pole axis in a field of view in front of the at least one pole piece. A probe head comprising a microwave resonator and at least one modulation coil or rapid scan coil produces an additional, time-varying magnetic field aligned along the pole axis. The probe head is arranged in the field of view, and a respective modulation coil or rapid scan coil is arranged between the microwave resonator and a respective pole piece. For each pole piece, at least a part of said pole piece is made of a function material having an electric conductivity σ.sub.f of 10.sup.4 S/m or less, and having a saturation magnetic flux density BS.sub.f of 0.2 T or more.

Provided is an electromagnetic device for magnetic particle imaging, including: a return yoke having a gap, which extends in a Y direction and forms a magnetic field space; a gradient magnetic field generating unit, which is provided to the return yoke, and is configured to generate, in the magnetic field space, a gradient magnetic field in an X direction, and to form, in the magnetic field space, a zero-field region extending in the Y direction; an alternating magnetic field generating unit, which is provided to the return yoke, and is configured to generate an alternating magnetic field in the magnetic field space; and a rotation mechanism configured to rotate the gradient magnetic field and the alternating magnetic field relative to a subject with a Z direction being a rotation axis.

A magnetic field concentrating or guiding device can include one or more coils, and one or more foil, tape and/or bulk superconductor structures disposed in one or more predetermined positions with relation to the coils. The one or more superconductor structures can form one or more magnetic field carrying regions. During operation, current passing through the one or more coils can generate one or more magnetic fields that are compressed or guided in the magnetic field carrying regions.

A gradient coil for an MRI apparatus is disclosed, comprising a main coil layer and a shielding coil layer. The shielding coil layer is arranged around the main coil layer, which includes an X, Y, and Z main coil set, and an X and Y end shielding coil set. The X end shielding coil set is connected in series with the X main coil set and used to form a shielding magnetic field in a direction opposite to the X direction. The Y end shielding coil set is connected in series with the Y main coil set and used to form a shielding magnetic field in the opposite direction to the Y direction. In the Z direction, the X end shielding coil set and Y end shielding coil set are disposed outside an imaging region enclosed by the main coil layer.

A fluid-cooled electromagnet includes an upper housing, a lower housing vertically aligned with the upper housing, a plurality of pancake coils disposed between the upper housing and the lower housing to be spaced apart from each other and sequentially stacked to have a washer shape, and at least one spacer, disposed between the upper housing and the lower housing, accommodating the pancake coils at regular intervals.