METHOD OF INDUCING SPIN ECHO SIGNALS Russian patent published in 1998 - IPC

FIELD: physical analytical methods. SUBSTANCE: in a method including affecting specimen, containing quadrupole nuclei with multilevel spin system, by radio-frequency pulses with basic frequencies equal to frequencies of three transitions, and recording response signals, as specimen, substance containing quadrupole nuclei and four-level spin system is selected. Two radio-frequency pulses with basic frequency equal to frequency ω₃ of upper transition is first emitted, and then remaining radio-frequency pulses with basic frequencies equal to ω₂ and ω₁ of middle and lower transitions. Duration of radio-frequency pulses in all induced transitions is set on the basis of maxima of observed signals. Time intervals between pulses in each transition are less than transverse relaxation time, and those between pulses in different transitions are less than longitudinal relaxation time. Invention allows exciting spin echo signals in three neighboring transitions of four-level spin system and increasing signal/noise ratio in observed signals in middle and lower transitions. EFFECT: increased accuracy of examining structure of chemical compounds. 5 dwg