NMR probe head with a backbone in the shielding tube

An NMR probe head configured for insertion into a magnet bore of a nuclear magnetic resonance (NMR) magnet system and comprising:

• in a coil region, a radio frequency (RF) coil arrangement configured to irradiate RF pulses into an NMR measurement sample and/or to receive RF signals from the NMR measurement sample and, when arranged in an NMR measurement operating state, is arranged in a measurement region around a magnetic center inside the magnet bore,
• electrical, mechanical and RF components,
• an elongated shielding tube (a) made of electrically conductive material that shields against RF radiation external to the probe head, (b) having a longitudinal axis, (c) surrounding the electrical, mechanical and RF components, and (d) through which electrical supply lines extend from a connection region arranged outside the measurement region in the NMR measurement operating state to the coil region,
• an elongated backbone (a) arranged inside the shielding tube (b) having an inherently rigid, mechanically stiff structure with continuous bores and/or connecting channels which run at least substantially parallel to the longitudinal axis of the shielding tube and accommodate the electrical supply lines, and (c) having a continuously electrically conductive outer surface which leads from the connection region to the coil region and is electrically conductively connected to an inner surface of the electrically conductive shielding tube via electrically conductive connecting elements, providing a continuous electrically conductive contour between the backbone and the shielding tube, wherein the continuous electrical contour between the backbone and the shielding tube comprises a plurality of waveguides parallel to the longitudinal axis of the shielding tube, and wherein a cross-sectional area of the waveguides is dimensioned such that each of the waveguides has a cut-off frequency which is above a highest measurement frequency of the NMR probe head.