Star-fst-l mailing list

[Tonko Ljubicic <tonko AT bnl.gov>]

Hello,

I'm done -- thanks!


On Wed, Aug 18, 2021 at 2:30 PM Tonko Ljubicic <tonko AT bnl.gov> wrote:
>
> Alright -- I'm on it and I'll let you know when done.
>
>
> On Wed, Aug 18, 2021 at 2:28 PM Xu Sun <sunxuhit AT gmail.com> wrote:
> >
> > Hi Tonko,
> >
> > Yes. Please go ahead and let me know when you are finished.
> > On my way to STAR, we could start to pull the detector after you are done.
> >
> > Best,
> >
> > Xu
> >
> > On Wed, Aug 18, 2021 at 8:15 AM Tonko Ljubicic <tonko AT bnl.gov> wrote:
> >>
> >> Hello Xu, all,
> >>
> >> before you pull the detector out today I would like 15-20 minutes to 
> >> take a run
> >> regardless of noise. This will give me some data to ponder while you
> >> are checking the noise sources.
> >>
> >> Would that be possible? Now?
> >>
> >>          -- Tonko
> >>
> >> On Wed, Aug 18, 2021 at 1:37 AM Xu Sun <sunxuhit AT gmail.com> wrote:
> >> >
> >> > Hi Flemming,
> >> >
> >> > The bias voltage is different in two tests.
> >> > For the test on 08/11/2021, the bias voltage is 50V for both inner and 
> >> > outer. This is because the detector is only half way in and we 
> >> > couldn't block the light.
> >> > For the test on 08/17/2021, the bias voltage is 140V for inner and 
> >> > 160V for outer.
> >> >
> >> > Best,
> >> >
> >> > Xu
> >> >
> >> > On Tue, Aug 17, 2021 at 7:34 PM videbaek <videbaek AT bnl.gov> wrote:
> >> >>
> >> >> Hi Xu,
> >> >>
> >> >> a question were the bias voltage the same in the two tests or did you 
> >> >> go
> >> >> to 140 for the outer. Just want to make sure I understand what you 
> >> >> did.
> >> >> I am coming in to the lab tomorrow as already planned and will see you
> >> >> in the hall
> >> >>
> >> >> flemming
> >> >>
> >> >> On 2021-08-17 19:11, Xu Sun wrote:
> >> >> > Hi All,
> >> >> >
> >> >> > We ramped the whole FST detector to the working HV last night and 
> >> >> > did
> >> >> > a readout test for all the modules.
> >> >> > There are two modules located at Disk 1 position 7 and Disk 1 
> >> >> > position
> >> >> > 11 (all belong to RDO2) showing an abnormal noise than the previous
> >> >> > test. The RO test results can be found in the attached file
> >> >> > (RDO2_140V_08172021.png).
> >> >> >
> >> >> > Both modules 1-7 and 1-11 were tested with 50V while the FST was 
> >> >> > half
> >> >> > way in the cone on 08/11/2021. The results then were quite normal 
> >> >> > and
> >> >> > could be found in the attached file (RDO2_50V_08112021.png).
> >> >> > The only difference between two tests, as far as we are aware, is 
> >> >> > the
> >> >> > position of the detector: on 08/11/2021 detector was half way in the
> >> >> > cone and on 08/17/2021 detector was at final position.
> >> >> > We have made sure the issue is on the purple cable and module side 
> >> >> > by
> >> >> > swapping connections through the readout chain.
> >> >> > Similar problems were found in the clean room RO test and were fixed
> >> >> > by adding grounding to the aluminum ring or replacing the purple
> >> >> > cable.
> >> >> >
> >> >> > We plan to pull the FST out tomorrow morning and check what 
> >> >> > happened.
> >> >> > We also plan to add additional grounding of 1-7 and 1-11 to the
> >> >> > aluminum ring instead of  only grounding to the T-board since it is
> >> >> > almost impossible to change the purple cable for Disk 1 (most inner
> >> >> > disk) on the scaffolding.
> >> >> >
> >> >> > Best,
> >> >> >
> >> >> > Xu
> >> >> > _______________________________________________
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> >> >> > Star-fst-l AT lists.bnl.gov
> >> >> > https://lists.bnl.gov/mailman/listinfo/star-fst-l
> >> >>
> >> >> --
> >> >> Flemming Videbaek
> >> >> senior scientist
> >> >> videbaek @ bnl.gov
> >> >> Brookhaven National Lab
> >> >> Physics Department
> >> >> Bldg 510D
> >> >> Upton, NY 11973
> >> >>
> >> >> phone: 631-344-4106
> >> >> cell     :  631-681-1596
> >> >
> >> > _______________________________________________
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