Gradient coil system for a nuclear spin tomography installation

Claim 1

In a gradient coil system for a nuclear spin tomagraphy installation which encloses a hollow cylindrical support body, the cylinder axis of which extends in the z direction of an orthogonal x-y-z coordinate system with the origin of the coordinates in the center of an imaging region, in which direction the magnetic field B z of a base field magnet comprising several field coils is also oriented, which gradient coil system contains, for generating a z field gradient which is largely constant in the imaging region at least two ring-shaped G z individual coils arranged at least approximately symmetrically to the x-y plane extending through the center of the imaging region, and further contains at least one set each of pairs of saddle-shaped G x and G y individual coils which are arranged at least approximately symmetrically with respect to said x-y plane and which are provided for generating x and y field gradients which are largely constant in the imaging region, the improvement comprising: (a) the prefabricated saddle-shaped G x and G y gradient coils on each side of the x-y plane being rigidly connected to each other to form a self-supporting partial basket; (b) several longitudinal support elements of non-magnetic insulating material extending in the z direction to which the prefabricated ring-shaped G z gradient coils are fastened and to which the partial baskets which are formed on both sides of the x-y symmetry plane are fastened to form a common self-supporting coil basket; and (c) insulating elastic support elements attaching the coil basket to the hollow cylindrical support body.