Re: UXNMR pulse programming of VD-related delays

Dr. Gerhard Eber (ge@bruker.de)
Wed, 21 Jun 95 11:29 MSZ

Dear Professor Stilbs,

I suppose that there is probably no solution to your problem if you really want
to use the variable delay list in a sense such that the vd is changed to
arbitrary length during the experiment. The calculations of delays and pulses
at the beginning of the pulse sequence are done at compile time and the results
are fixed such that they cannot be changed at run time. It would contradict the
definition of a variable delay to use it in such a context. This is what causes
the compilation error.
Constant time experiments where a third pulse is moved between 2 pulses with a
constant distance are possible for AMX/ARX systems only with linear movements
of the pulse like in the following example:

xyz,
...
p1
d0
p3
d1
p2
...
d10 id0 ; increment delay d0 by IN0
d10 dd1 ; decrement delay d1 by IN1
lo to xyz times td1

In this example the time between p1 and p2 is constant if the increments IN0
and IN1 are equal. If there is a crossing of pulses during the experiment, one
has to write explicitly two parts of the experiment, one with the pulse before
the crossing and one after.

I hope that this will help you to execute the experiment. Such limitations do
exist for AVANCE spectrometers, because there such calculations can be
performed at run time.

Best regards

Gerhard Eber

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