[dsg-hdice] NMR power supply synchronization

[Peter Bonneau]

Andy,

The issues Xiangdong reported with the NMR program include abnormal or 
incomplete field readings, and program hang-ups.These issues appeared 
during the first extended running of the NMR system with a target. You 
may recall that DSG had completed the initial Rack #2 NMR program 
revisions and debugging last year.It is good to know that the program 
was finally tested.

DSG determined these issues (reported to us on 7/28/2017) have a common 
underlying cause: Intermittent (and infrequent) power supply 
communication errors. Hence, DSG investigated the GPIB interface 
hardware and rewrote the NRM power supply device drivers. *A DSG test 
run of 1500 sweeps has been completed successfully. All known issues 
with the Rack #2 NRM system has been resolved.*

Regarding the addition of current shunt synchronization, this work 
requires both hardware modifications and extensive changes to the 
original NMR base programs. This base NMR hardware and software must be 
stable and *verified by HDice* before the current shunt synchronization 
is implemented. Otherwise, the root cause of any error during 
synchronization debugging would be ambiguous and would extend greatly 
the time needed to complete this task.

Attached to this email is a status summary of NMR hardware and program 
work by DSG.

Peter



On 9/11/2017 11:58 AM, Dr. A.M. Sandorfi wrote:
> Re: [dsg-hdice] NMR power supply synchronization Dear Peter,
>
> As you are probably aware, Xiangdong has been in frequent contact with 
> Amanda over the last month. Skipping over the details of those 
> iterations, the overall status is that rack #2 is failing in many 
> different ways. (Oddly, I have the general impression that it’s 
> condition is worse that it was last December. But that maybe because 
> the December tests didn’t get to the point of scanning a real target.) 
> In any case, we are about to condense new HD targets and so will need 
> to keep rack #1 through the target cycle, which will be several 
> months. Please plan on taking rack #2 back to the DSG, fixing its 
> problems, and reinstalling the shunt with readout synchronized to the 
> field sweeps.
>
> Thanks,...Andy Sandorfi
>
>
>
>
>
>     On 8/14/17, 3:32 PM, "Peter Bonneau" <bonneau at jlab.org> wrote:
>
>     Hi Andy,
>
>     It is our understanding that HDice is currently using the
>     equipment in NMR rack #1 to verify the performance of the rack #2
>     which DSG as has already upgraded.
>
>     As previously requested by the HDice group, DSG will upgrade NMR
>     rack #1 upon completion of rack #2 testing. During the rack #1
>     upgrade, DSG plans to use the rack #1 equipment for the advanced
>     debugging and testing phase of the shunt synchronization project.
>     Because we were waiting for the test results for rack #2 and
>     necessary equipment from rack #1, we had put the synchronization
>     project on hold.
>
>     We are happy to hear that the tests on NMR rack #2 has started. In
>     Xiangdong’s July 28th email, rack #2 was used to test a HDice eHD
>     target cell with good initial results which outperformed rack #1.
>     DSG has also completed debugging all NRM program issues that were
>     reported during this testing.
>
>     Is there a time table for completion of testing for HDice Control
>     Rack #2?
>
>     Peter Bonneau
>
>
>
>
>
>     On 8/10/2017 12:35 PM, Dr. A.M. Sandorfi wrote:
>
>
>
>         Hi Peter,
>
>         As we spoke a few weeks ago, we will be needing to operate the
>         NMR rack with
>         the shunt synchronized to the lock-in. You mentioned that was
>         put on hold
>         last January while you dealt with other pressing jobs. Do you
>         have a time
>         table for completion of this task?
>
>         Andy Sandorfi
>
>
>
>
>         On 8/4/17, 4:59 PM, "Amanda Hoebel" <amandah at jlab.org>
>         <mailto:amandah at jlab.org>  wrote:
>
>
>
>             Hi,
>
>             A new LED has been installed in the transformer box and
>             the box was placed
>             back in the NMR rack.
>
>             Regards,
>             Amanda
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>
>
>
>
>
>
>
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