Helmut Kess

5280249 Circularly polarizing local antenna for a nuclear magnetic resonance apparatus

In a circularly polarizing local antenna for a nuclear magnetic resonance imaging apparatus, a first antenna system is fashioned as a frame coil. A second antenna system has two sub-coils arranged lying opposite one another, which are both penetrated by the frame coil. The combination of the first and second antenna systems exhibits a circularly polarizing characteristic in a volume that lies inside the frame coil and outside the subcoils.

NMR tomography apparatus having iron-free dc motors for capacitor adjustment

A nuclear magnetic resonance tomography apparatus has a coil for generating a basic magnetic field, a gradient coil and measuring coils. A capacitor arrangement precisely adjusts the resonance of the measurement coil to the basic field coil. An iron-free dc motor is disposed within the field generated by the basic field coil for physically adjusting the plates of the capacitors connected in the circuit including the measurement coil. The rotor and coils of the iron-free dc motor are disposed within the basic magnetic field such that the basic magnetic field functions as the stator field for operating the motor.

Double resonance antenna arrangement for a nuclear magnetic resonance apparatus

In a double resonance antenna arrangement for a nuclear magnetic resonance apparatus having at least one conductor section that defines an examination region, a series circuit of a capacitive element and an inductive element is connected in parallel with at least a part of the conductor section.