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An NMR Probe as part of the NMR instrument located in the magnet’s ambient temperature bore and is used for exciting the nuclear spins and detecting the signal. The NMR probe contains RF circuits that apply the observe, lock, and one or more decouple frequencies to the sample and detect the resulting NMR signals. In general, once the sample is inserted, the probe should be tuned and matched. This is usually achieved by adjusting two variable capacitors in the circuit. Tuning and matching reduces reflected power and increases the quality factor Q, leading to shorter pulse widths and better sensitivity. Proper tuning/matching of the circuits of Probe for the observe and decoupling nucleus frequencies provides better performances of 1D and 2D NMR experiments and yields good quality NMR spectra.

Tuning is the process of adjusting the frequency until it coincides with the frequency of the pulses transmitted to the circuit.

Matching is the process of adjusting the impedance of the resonant circuit until it corresponds with the impedance of the transmission line connected to it. This impedance is 50 W. Correct matching minimizes the power that is transmitted to the coil.

  The tuning and matching knobs of the Probe have a limited range and attempting to turn them beyond this range will damage the probe and in the event of damage the Probe needs a costly factory repairing. To avoid this, tuning on 600 MHz NMR instrument is prohibited by any NMR user, should be done only by NMR Facility staff.

 For the INOVA 600MHz NMR instrument two probes are available:

Direct detection Probe (SW/PFG): in normal configuration, the Proton channel is tuned to proton, X channel is tuned to carbon and the Lock channel is tuned to deuterium. The X channel can be tuned also from nitrogen to phosphorus frequency.

Indirect detection Probe (H{13C/X}PFG: in normal configuration,  the Proton channel is tuned to proton, Carbon channel is tuned to carbon, Lock channel is tuned to deuterium, the X channel can be broad band tuned from nitrogen to phosphorus frequency. This probe is designed for inverse detection triple resonance experiments. The probe has optimal proton sensitivity and capability for simultaneous or single irradiation at 13C and X frequencies. 



3 full-bands RF channels, all of them with linear amplifiers,

fine attenuators and waveform generators

PFG z axis

Automated deuterium gradient shimming module


Oxford, 14.2 T (600 MHz)

 Shims   28

FTS variable temperature unit                                                       

Linux based Workstation, release 6.1 (Santiago)

Software: VNMRJ, Version 4.2, Revision A                                      

Probes: 1H-19F/15N-31P PFG Switchable Broadband Probe

1H {13C/31P – 15N} 5mm PFG Triple Resonance Probe