摘要:
The magnet contains a magnetic yoke and two pole shoes between which a magnetic field of high homogeneity is formed. The pole shoes are provided with special pole piece device. Each pole piece device is spaced from a base part facing the yoke by a narrow correction air gap. In accordance with the invention, each pole piece device contains two plate-like pole piece elements which are parallel to each other and spaced apart by a gap of predetermined width. In this connection, the plate element facing the base part has a relative permeability (.mu..sub.r 1) which is smaller by at least a factor of 5 than the plate element facing the useful volume, the relative permeability (.mu..sub.r 2) of which element is at least 10,000.
摘要:
A magnet contains a magnetic yoke and two pole shoes, between which a magnetic field of great homogeneity is formed. The pole shoes are provided with special pole plates. At least one pole plate (11d) is separated from a base part (11b) facing the yoke by a narrow correction air gap (15), and can be aligned by means of mechanical setting devices. According to the invention, each pole shoe (11) has a bead-like edge piece (11c) for field correction at its edge area (17b), which surrounds an inner pole shoe area (17a). In this region, the pole plate (11d), which can be aligned laterally separated from the edge piece (21).
摘要:
The magnetic device of a nuclear spin tomography system contains several magnet coils which surround an interior suitable for accommodating a body to be examined, and generate therein an at least largely homogeneous magnetic field. The device also includes an approximately cylindrical shielding device which surrounds the coils and consists of ferromagnetic material, and has at each end face thereof, a washer-shaped part with a central opening with a predetermined radius with respect to the cylindrical axis, in order to make possible good lateral access to the magnet coils and to provide sufficient space for laterally protruding parts. At least four beam-like shielding elements of identical design are used to form the approximately cylindrical part of the shielding device, the elements being uniformly distributed in the circumferential direction over the cylindrical surface. The shielding elements may have rectangular or triangular cross-sectional shapes.
摘要:
Magnet coil system for nuclear spin tomography has superconducting coils for generating a homogeneous magnetic base field and nonsuperconducting coils within an interior region defined by the base field coils for developing magnetic field gradients. At least one cooled radiation shield of electrically and thermally conductive material is arranged between the gradient coils and the superconducting base field coils. To prevent eddy currents started in the radiation shield from distorting the gradient fields, the radiation field contains superconducting material of a "second kind" that is a high temperature superconductor. The superconductor is in a nonsuperconducting state at the start of an excitation process for the base field coils and in a superconducting state during the undisturbed operation of the magnet coil system.
摘要:
A drive unit contains an exciter winding, an magnetic armature part which is set into an oscillating vibration movement, by the magnetic field of the winding, about a center position in an axial direction and at least one spring which is clamped in a fixed manner in a clamping position and whose oscillating end engages with the armature part, acting in the direction of movement. In the center position of the armature part, the point of engagement of the spring with the armature part is axially offset by a predetermined distance in relation to the clamping position in order to appropriately offset the armature part when in a rest position.
摘要:
A cryogenically stabilized superconductor in cable form comprises several superconducting elements which contain twisted conductor filaments of superconductive material which are embedded in a matrix material of predetermined electric conductivity and which are twisted with several stabilizing elements of thermally and electrically highly conductive material which is electrically normal conducting at the operating temperature of the superconductor and the electric conductivity of which at the operating temperature is substantially higher than that of the matrix material of the superconducting elements disposed parallel thereto. So this superconductor will be capable of carrying large currents, will have high cryogenic stability and at the same time have only small alternating field losses, pairs of stabilizing elements and superconducting elements form respective stabilized subconductors, the stabilizing elements of which are connected in an electrically conducting manner only at individual points disposed one behind the other in the lengthwise direction of the conductor to the respective superconducting elements; and the subconductors are twisted together and are electrically insulated from each other in such a manner that an electrically highly conducting cross connection of all subconductors is provided only after one or more respective twisting lay lengths.
摘要:
A superconductor having a plurality of superconducting filaments embedded in a solid conductor of normal conducting material, and with each of the filaments being twisted about the longitudinal axis of the superconductor to form a helix which is concentric with respect to the longitudinal axis, in order to suppress coupling effects occurring between filaments on circles with different radii in time variable magnetic fields. Each of the filaments is twisted about the conductor axis to provide alternating equal length sections along the conductor axis with opposite senses of rotation of the filaments about the conductor.
摘要:
A drive device comprising at least one exciter winding, which is used to produce a modifiable magnetic field, consisting of an associated magnetic-flow guiding main yoke body and a counter yoke body, in addition to an armature body, which can be set into an axially oscillating motion, with two permanent magnetic magnet parts which are disposed between the yoke bodies. The limbs of the yoke bodies have reciprocal distances and predetermined axial widths which are adapted to the axial extension of the magnet parts.
摘要:
A marine propulsion system may include at least one electric motor and a converter-fed electrical power supply. The at least one electric motor may be arranged in a propeller shaft pipe at a stern of a vessel for driving at least one vessel propeller, and may include at least one drive machine for driving at least one generator.
摘要:
A method for manufacturing a disc-shaped curved magnet coil, particularly for a system for accelerating and/or storing electrically charged particles such as electrons. The conductors of the coil to be made are to be arranged around a winding core having a convex outside and a concave inside and are then to be fixed in position around the winding core. A coil form or fitting piece of predetermined shape is first added to a winding core, so that a provisional winding body with only positive radii of curvature on its outsides is formed. The conductors are wound under tension around the winding body and subsequently are fastened only to the winding core of the winding body and, after the coil form is removed, the thus exposed conductor portions facing the region of the concave inside of the winding core are pressed against this inside and fixed in position.