CPMG pulse program with HADC digitizer and analog filtering for AVANCE AQX.
Contribution of Y. Millot
CPMG pulse program with HADC digitizer and analog filtering for AVANCE AQX.
Contribution of Y. Millot
J. T. Cheng and P. D. Ellis ( J. Phys. Chem. 93, 2549-2555, 1989) studied the adsorption of Rb+ to γ-alumina using CPMG echo train pulse sequence. The Fourier transform of the fid followed by the train of m echoes is a spikelet spectrum. The latter has a better signal-to-noise ratio than that from one-pulse experiment.
;Carr-Purcell-Meiboom-Gill echo train acquisition with analog filtering ;and HADC digitizer #include <Avance.incl> define delay dx define delay px "l2 = 2*l1" "l4 = l3*l2 + l1" "dx = dw" "px = dw" ze ; clear memory, new data replace old data. start, d1 pl1:f1 ; recycle duration. p1:f1 ph1 ; 90° pulse with x phase. d11 ; echo delay d11 + d14. d14 ; echo delay d11 + d14. p2:f1 ph2 ; 180° refocussing pulse with y phase. d11 adc ph31 ; echo delay d11 + d14. d14:e ph0 syrec ; echo delay d11 + d14. fid, dx ; dx + px, the dwell time for the external dwell-pulse. px:x ; external dwell-pulse for the fid data digitizing. lo to fid times l1 ; loop for the fid data digitizing. nbecho, d11:e ; echo delay d11 + d14, sytra not required. d14:e ; echo delay d11 + d14. p2:f1:e ph3 ; 180° refocussing pulse with y phase. d11:e syrec ; echo delay d11 + d14. d14:e ph0 ; echo delay d11 + d14. echo, dx ; dx + px, the dwell time for the external dwell-pulse. px:x ; external dwell-pulse for an echo data digitizing. lo to echo times l2 ; loop for an echo data digitizing. 0.1u lo to nbecho times l3 ; loop for the echo train acquisition. rcyc=start ; loop to start, ns times for averaging. 100m wr #0 ; delay for disk I/O, store signal. ;------------------------------------- tmp, 100u lo to tmp times l4 ; provide the time-domain size td = 2*l4. ;------------------------------------- exit ; end of the pulse program. ph1 = 0 0 1 1 2 2 3 3 ; f1 channel p1 pulse phase ph2 = 1 3 2 0 3 1 0 2 ; f1 channel first p2 pulse phase ph3 = 1 3 2 0 3 1 0 2 3 1 0 2 1 3 2 0 ; f1 channel second p2 pulse phase ph31 = 0 0 1 1 2 2 3 3 ; receiver phase ph0 = 0 ; receiver reference phase ;pl1: f1 channel power level for p1 and p2 pulses ;d11: 10u ;l1: number of digitized points for the fid ;l2: number of digitized points for an echo ;l3: number of echoes ;ns = 16*n ;2*dw = dx + px, dwell-time for the external dwell-pulse ;aq = 2*dw*l4 = dw*td