Bruker Biospin Gmbh

Broker Biospin Gmbh

Yit Aun Lim

Werner E Maas

Eckhard Bez

Xiaozhong Zhang

In a nuclear magnetic resonance probe, the sample coil is connected to the RF excitation source via transmission lines that are arranged to generate one or more nodal points at theH excitation frequency along their lengths and a balanced magnetic filed profile within the sample coil. Heat exchangers are then connected directly to the inner conductor of the transmission line at these nodal points. The transmission line inner conductors are in direct contact with the sample coil and efficiently cool the coil to cryogenic temperatures without interfering with theH resonance or RF profile.

Nuclear magnetic resonance probe with cooled sample coil

A nuclear magnetic resonance (NMR) probe circuit is used with a sample coil tuned to a primary frequency f. The circuit is arranged to have a plurality of points of electric field minima at the ffrequency. One or more additional frequencies may be coupled to the circuit at these points, without interaction with f. The probe circuit also uses an impedance coupled between two of the minima points that affects the frequency response at the additional frequency or frequencies, without affecting the frequency response at f. The impedance may be made adjustable to allow tuning of the relative frequency resonances.

NMR probe circuit with nodal impedance bridge

A circuit for a nuclear magnetic resonance probe uses three resonators to create resonances intermediate to the resonator resonant frequencies. The circuit is particularly useful for creating magnetic fields for two closely spaced high frequencies, such as those used for the excitation ofH andF. The resonators are arranged in a parallel combination, or the electrical equivalent thereof, with input ports connected to it for inputting the desired high frequency resonances. Admittance inverters may be used to provide isolation between the input ports. Some of the resonators and the admittance inverters may be transmission lines. The transmission lines may have additional ports for additional input signals of lower frequencies located at null points for the frequencies of the signals coupled to the primary input ports. Adjustable dielectric components in the resonator transmission lines may be used for tuning purposes.

Growing community of inventors

Boston, MA, United States of America

Yit Aun Lim