Varian, Inc.

Joseph Murphy

James Finnigan

Weston A Anderson

NMR (Nuclear Magnetic Resonance) capacitor switches allow for adjusting the resonant frequency ranges of NMR measurement circuits by inserting or removing capacitors having different values into the circuits. A change of position of a single switching member is used to change the contact state of at least two capacitors. In some embodiments, at least two pairs of external contacts are disposed at distinct longitudinal levels along a channel, and a slider including multiple longitudinally-spaced capacitors is moved longitudinally within the channel to establish electrical contact between the external contact pairs and different capacitors along the slider. In other embodiments, two capacitor columns are disposed along the channel, and a movable longitudinal member establishes electrical contact between the two columns at different longitudinal levels along the columns. In some embodiments, capacitor covers or intracapacitor blocks are provided to protect the capacitors. An auxiliary inductor may also be inserted into the circuits.

Capacitor switches for NMR

An insertable wand is used in a multi-nuclear NMR probe enabling the probe to detect and obtain data from various combinations of nuclei. The particular combination of frequencies is determined by various electrical components, and parts within the wand that are designed to cooperate with a tube, to form an adjustable &frac14; wave assembly. The adjustable &frac14; wave assembly component in the wand comprises a metal rod with an adjustable conductive collar and spring contacts such that when inserted into the tube, the rod and the tube to form an adjustable &frac14; wave circuit or a &frac14; wave shorted stub. The tube may form part of the wand or the probe. When the wand is plugged into the probe, the combination of the NMR coil within the probe and the adjustable &frac14; wave shorted stub provides means for the NMR circuit to resonate at two separate frequencies.

Growing community of inventors

South San Francisco, CA, United States of America

Joseph Murphy