Multipulse sequences for explosives detection by NQR under conditions of magnetoacoustic and piezoelectric ringing

• DOI: 10.1007/bf03166540
• Publication Date: 2009-10-14T07:45:40Z
• Authors: V. T. Mikhaltsevitch; T. N. Rudakov; J. H. Flexman; P. A. Hayes; W. P. Chisholm
• Keywords: Ringing; Pulse sequence; Sequence (biology); SIGNAL (programming language); Saturation (graph theory)

A number of methods for cancelling magnetoacoustic and piezoelectric ringing signals in the spectroscopy of the nuclear quadrupole resonance are presented. The suggested methods include using the sequence (ϕ0)ϕ-(τ-ϕx-2τ-ϕ y -2τ-ϕ−x -2τ-ϕ−y -τ) n and a multipulse analog of the two-pulse Hahn sequence with the first pulse replaced by a short steady-state sequence. Another method presented is the method of orthogonal effective fields for a fast saturation of the quadrupole spin system which can be used for subtracting the magnetoacoustic and piezoelectric components from the signal. The suggested methods can be used for the practical purposes of detecting explosive substances and narcotics.