Nuclear magnetic resonance pulse sequence for optimizing instrument electrical power usage

摘要

A method for acquiring nuclear magnetic resonance measurements of a material. The method includes inducing a static magnetic field in the material, and inducing a first radio frequency magnetic field in the material to reorient nuclear magnetic spins in the material. The first radio frequency magnetic field has an amplitude and a duration selected to reorient the nuclear magnetic spins by about 90 degrees from their alignment with the static magnetic field. A second radio frequency static magnetic field is induced in the material. Nuclear magnetic resonance signals are detected after inducing the second radio frequency magnetic field. The steps of inducing the first and second radio frequency magnetic fields and detecting signals are repeated and the detected signals are stacked. The second radio frequency magnetic field has a duration and amplitude selected to reorient the nuclear magnetic spins by an angle selected to provide the stacked signal with improved signal to noise ratio compared to a single signal wherein the selected angle is 180 degrees, while consuming the same electrical power as is used to generate the single signal having the 180 degree selected angle. In the preferred embodiment, the selected angle is in a range of about 80 to 120 degrees.