[Rgc] [EXTERNAL] Problem with FTCal

[Christopher Keith]

I’d prefer not to cool the target to look for an NMR signal at 0.77 T, only to warm it and remove it afterwards.  Seeing the signal at that low field is not guaranteed, and it cause another delay of 2-3 day.  We should think of another way to check the linearity of solenoid.

Chris


On Jan 17, 2023, at 1:04 PM, Morgan Cook IV via Rgc <rgc at jlab.org<mailto:rgc at jlab.org>> wrote:

The HV cable probably got disconnected when I was arranging cabling and piping out of the cone of acceptance.

I'd say 3-4 days, depending on how long it takes to disconnect/reconnect the target and move it upstream/downstream. And I'm guessing that the solenoid work needs to take precedence... we're scheduled to cool down the target tomorrow in order to check the field... and I don't know how long that will take.

-Morgan
________________________________
From: Eugene Pasyuk <pasyuk at jlab.org<mailto:pasyuk at jlab.org>>
Sent: Tuesday, January 17, 2023 12:55 PM
To: silvia at jlab.org<mailto:silvia at jlab.org> <silvia at jlab.org<mailto:silvia at jlab.org>>; Raffaella De Vita <Raffaella.Devita at ge.infn.it<mailto:Raffaella.Devita at ge.infn.it>>
Cc: Kuhn, Sebastian E. <skuhn at odu.edu<mailto:skuhn at odu.edu>>; rgc at jlab.org<mailto:rgc at jlab.org> <rgc at jlab.org<mailto:rgc at jlab.org>>; Denny Insley <dinsley at jlab.org<mailto:dinsley at jlab.org>>; Morgan Cook IV <mcookiv at jlab.org<mailto:mcookiv at jlab.org>>; Patrick Achenbach <patricka at jlab.org<mailto:patricka at jlab.org>>; Stepan Stepanyan <stepanya at jlab.org<mailto:stepanya at jlab.org>>
Subject: RE: [EXTERNAL] Problem with FTCal

Getting to the detector will require breaking down the upstream beamline, taking the raster magnet off the target cart, moving the target upstream, moving CVT upstream, moving solenoid upstream, and moving HTCC. Then we will have to put everything back together and align it. This also may interfere with the solenoid work.

Denny, Morgan,  could you give an estimate of how long this work may take?

-Eugene

> -----Original Message-----
> From: silvia at jlab.org<mailto:silvia at jlab.org> <silvia at jlab.org<mailto:silvia at jlab.org>>
> Sent: Tuesday, January 17, 2023 12:42
> To: Raffaella De Vita <Raffaella.Devita at ge.infn.it<mailto:Raffaella.Devita at ge.infn.it>>
> Cc: Kuhn, Sebastian E. <skuhn at odu.edu<mailto:skuhn at odu.edu>>; rgc at jlab.org<mailto:rgc at jlab.org>; Eugene Pasyuk
> <pasyuk at jlab.org<mailto:pasyuk at jlab.org>>; Denny Insley <dinsley at jlab.org<mailto:dinsley at jlab.org>>; Morgan Cook IV
> <mcookiv at jlab.org<mailto:mcookiv at jlab.org>>
> Subject: Re: [EXTERNAL] Problem with FTCal
>
> Dear Raffaella and Eugene,
> when you say "a lot of work", do you have an estimate of how long trying to fix
> this issue would take? We still have roughly one week before the beam comes
> back. Giving up a priori to 1/4 of our data is a bit tough for me, especially given
> the lots of issues this experiment had until now, and the fact that we are not
> going to have an extension at the end of March.
> If you could please clarify what time scale we're talking about for the repairs, it
> would be very helpful to make our mind up.
> Thank you!
> Best regards,
> Silvia
>
>
> > Dear Sebastian and Silvia,
> >
> > Performing the final checkout on the FT, we found that we are not
> > getting useful signals from one quadrant of the calorimeter. You can
> > find more details in https://logbooks.jlab.org/entry/4111492
> > <https://logbooks.jlab.org/entry/4111492>.
> >
> > I am not sure when it happened but it is consistent with an HV cable
> > being disconnected on the detector side.
> >
> > Since fixing this requires having access to the detector, which is a
> > lot of work, Eugene asked me to inform you and ask you for feedback on
> > whether you would like to have this fixed or if you would accept
> > running with a missing quadrant.
> >
> > Best regards,
> >      Raffaella
>

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