Composite-pulse program for Bruker MSL spectrometer

The composite-pulse sequence, introduced by M. Mehring's group, cancels the spurious signals (ringing of the nmr probe head and piezo electric signal) that distort the base line of the NMR spectrum. There are three RF pulses in this sequence. As a result, there is no excitation condition of the quadrupolar spins that allows us to quantify the number of spins in the crystal. However, the "dead time" necessary for this sequence is four times smaller than that for the one-pulse sequence.

  PROT F1 F2 XT               ; protect all channels

  START, 50U
         10U
         VD [F1 @PLS1 RGATE]  ; the first-pulse duration p1
         VD [F1 @PLS2 RGATE]  ; the second-pulse duration p2
         VD [F1 @PLS3 RGATE]  ; the third-pulse duration p3
         D3 [STA]             ; acquisition delay
         D0                   ; recycle duration
         ++PLS1               ; increment p1 pulse phase
         ++PLS2               ; increment p2 pulse phase
         ++PLS3               ; increment p3 pulse phase
  GOTO START

  BEGIN LISTS
  PLS1,  -x -x  x  x   -y -y  y  y    x  x -x -x    y  y -y -y
  PLS2,   x  x  x  x    y  y  y  y   -x -x -x -x   -y -y -y -y
  PLS3,   x -x -x  x    y -y -y  y   -x  x  x -x   -y  y  y -y
  RLS,    x -x  x -x    y -y  y -y   -x  x -x  x   -y  y -y  y
  END LISTS

  ; RECEIVER MODE: RPN
  ; TRIGGER MODE:  NT
  ; THE THREE PULSE DURATIONS ARE IDENTICAL
  ; THIS PULSE PROGRAM IS PROVIDED 
  ; BY D. Müller, BRUKER (KARLSRUHE), GERMANY