Pulse sequence trouble

Jeff de Ropp (jsderopp@ucdavis.edu)
Tue, 18 May 1999 12:51:42 -0700

Dear BUMmers,

We are trying to write a sequence that will collect two files, one for
Na23 and one for P31, in interleaved fashion on a Avance DRX. We have a
custom probe built for this purpose. Now the problem is we can't get the
sequence to collect two files (never mind for the moment anything about
Na23/P31 switching).

Here it is:

*****************

; Author Jeff Walton, modified by jkj and moj 5/14/99

; This program is to interleave Sodium and Phosphorous data aquisition

; Both nuclei are aquired using channel 1

; pl1 is the power level for a Sodium 90

; pl2 is the power level for a Phosphorous 90

; FQ1LIST should be set to Na23

; FQ2LIST is set to P31

; set nbl=2

20u ze ; zero memory buffers

1 20u pl1:f1 ; set the power level on F1 for 23Na

d1 fq1:f1 ; set channel 1 to 23Na frequency stored FQ1list


10u st0 ; make buffer 1 the acquisition buffer

2 d1 ; wait 23Na recycle time

3 3u ph1 ; set the phase of the 23Na pulse

(p1 ph1):f1 ; apply the 23Na pulse

go=2 ph31 ; Acquire 23Na FID

wr #1

ifp ; write 23Na FID to disk


20u pl2:f1 ; set the power level on F1 for 31Pa

4 d1 fq2:f1 ; set channel 1 to 31Pa frequency stored in FQ2list

10u st ; increment active aquisition buffer to buffer 2

5 d2 ; wait 31P recycle time

6 3u ph1 ; set the phase of the 31P pulse

(p1 ph1):f1 ; pulse on 31P

go=5 ph31 ; Acquire 31P FID

wr #2

dfp


lo to 1 times l1 ;l1 is the number of times a set of Na and P set is
taken

exit

ph1=0 1 2 3

ph31=0 1 2 3

;parmod = 2D

For the moment we are just trying to collect both files as C13 data. We
define two freq lists, which at the moment are just using the C13 base
frequency with zero offset. We also define a dslist.

Here are the freq lists (for the moment both are the same):

<bigger>O 125.7665423

0

</bigger>

Here is the dslist:

<bigger>ds_c13a 1 1 disk2 deropp new

ds_c13b 1 1 disk2 deropp new

</bigger>

The sequence compiles OK and if we open the acq window we can see it
acquiring FIDs. But when the experiment is over we do not have a ser
file in <bigger>ds_c13a. It makes the ds_c13a directory on the disk and
puts params there but no data is saved. The ds_c13b directory does have
a ser file which can be transformed with xf2 to give a spectrum.

Any ideas on what is going wrong would be greatly appreciated. And if
you have a sequence for a DRX running xwinnmr2.5 that accomplishes what
we need that would be OK too.

Thanks,

</bigger>

Jeff de Ropp

NMR Facility

UC Davis

One Shields Avenue

Davis CA 95616

jsderopp@ucdavis.edu

530-752-7677

530-752-8109 Fax

NMR Facility Web site URL is:

http://www.nmr.ucdavis.edu/

Alternate, equivalent website is:

http://trc.ucdavis.edu/faculty/jsderopp/HOMEPAGE.html