4.11 MREV8 and CYLMREV - Multiple Pulse Line Narrowing (8-pulse cycle)
01-999162-00 C0402 VNMR 6.1C User Guide: Solid-State NMR
70
4.11 MREV8 and CYLMREV - Multiple Pulse Line Narrowing
(8-pulse cycle)
MREV8 (Figure 24) is a sequence used for
1
H CRAMPS. CYLMREV is a modification
that allows quadrature detection with the transmitter in the center of the spectrum. The
sequences are applicable for UNITYplus and
UNITY
INOVA as well as UNITY and VXR-S
with a Sync Module.
Macros
The macro mrev8 converts a S2PUL or FLIPFLOP data set for BR24. cylmrev converts a
data set for quadrature MREV8. All relevant parameters are preserved if the initial data set
is FLIPFLOP, BR24, CYLBR24, MREV8 or CYLMREV.
Parameters
pw is the 90
o
degree pulse-length, in microseconds.
tau is the interpulse delay, in microseconds, including pw. The MREV8 cycle is 12*tau
long and is repeated np/2 times to build up a FID.
trig='y' for UNITY and VXR-S with a Sync Module. Otherwise trig='n'.
tauc is the cycle time, in microseconds and is the actual dwell time for the FID. tauc is not
changed and is for information only.
mp_at is the sum of all cycles, in microseconds, and is the true acquisition time. mp_at
is not changed and is for information only.
sw=2e6 turns on the fast ADC without analog filters. sw does not determine the dwell time
(see tauc).
scalesw is a scale factor that converts sw=2e6 to the correctly scaled spectral width.
scalesw=(1.0/tauc*sw)*S where S is the multiple-pulse scale factor for MREV8
(0.471 for ideal pulses).
rof1 and rof2 (see 4.9 “FLIPFLOP - Pulse Width and Phase Transient Calibration,”
page 68)
tau 2*tau
pw
acqprep
0321
03 2
1
d1
'np'/2 times
Figure 24. MREV8 Pulse Sequence