DQ Solomon echo pulse program for Bruker MSL spectrometer

To cancel the central transition FID following the second pulse, we apply the double-quantum (DQ) filtered Solomon echo sequence. The duration tau2 between the two pulses must be shorter than that of the central transition FID. Thanks to phase cycling, only the DQ coherences generated by the first pulse are converted back to -1Q coherences as echoes of satellite transitions by the second pulse. Solomon echoes are observed in the two channels of the receiver.

  PROT F1 F2 XT               ; protect all channels

  START, D1 [F1 @PLS1 RGATE]  ; the first-pulse duration p1
         D6 [         RGATE]  ; spacing between pulses
         VD [F1 @PLS2 RGATE]  ; the second-pulse duration p2
         D7 [STA      RGATE]  ; acquisition delay
         AQ                   ; acquisition
         D0                   ; recycle duration
         1M
         ++PLS1               ; increment p1 pulse phase
         ++PLS2               ; increment p2 pulse phase
  GOTO START

  BEGIN LISTS
  PLS1,  -x  x -y  y    x -x  y -y    y -y -y  y    x -x -x  x
  PLS2,  -x -x -y -y    x  x  y  y   -x -x  x  x    y  y -y -y
  RLS,    x  x  y  y   -x -x -y -y   -x -x  x  x    y  y -y -y
  END LISTS

  ; RECEIVER MODE: RPN
  ; TRIGGER MODE:  NT