DQ Solomon echo pulse program for Bruker ASX 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.

    ze
    rp1            ; reset phase ph1 of the first pulse p1
    rp2            ; reset phase ph2 of the second pulse p2
    rp3            ; reset the receiver phase
  1 d1:c4 ph1 tlo  ; recycle duration d1
                   ; tlo set to drive HP X amplifier
    p1:c4 ph1      ; the first-pulse duration p1
    d6:c4          ; spacing between pulses
    p2:c4 ph2      ; the second-pulse duration p2
    2u:c4
    go=1  ph3      ; acquisition
                   ; loop to 1, NS times for averaging
    wr #0
  exit

  ph1= (4) {0 2 1 3}^1^2^3   ; p1 pulse phase
  ph2= (4) {2 2 2 2}^1^2^3   ; p2 pulse phase
  ph3=     {2 2 0 0}^1^2^3   ; receiver phase