[Primexd] FCAL bad channel status

[Alexander Somov]

Thanks a lot Colin for the update (and quick response). It would
be great if can replace these bases during this week (the hall
will be closed later today and will be re-opened tomorrow).

We can take LED data today and check the status.

Cheers,
        Sasha


On Wed, 28 Nov 2018, Colin Gleason wrote:

> Hi Sasha,
>
> I suspect there are around 5-10 bad/suspicious FCAL channels. I know of 2
> that are dead and 3 that are just showing noise. I will replace these after
> lunch. Someone either forgot to turn on the FCAL communications yesterday
> or has turned it off today, so I do not know all channels. The ones I know
> of are in (X,Y):
> bad signal:
> 16 8
> 26 0
> 27 -6HV:
> -8 28
> 14 21
>
> There are likely a few bases whose HV is below their set point. We usually
> keep these in the FCAL until they die, or, if we have enough spares
> available, will swap them out.
>
> Currently we have 16 spares ready to go in, with more ready to be repaired
> by Chris and Nick. The base failure rate had dropped to less than 2 per
> week by the end of the run, so we should be able to manage replacements
> through the rest of the Fall run. I think Chris and Nick have been busy
> with installation, but once that is complete we can get them to repair more
> bases for the spring.
>
> -Colin
>
> On Wed, Nov 28, 2018 at 11:25 AM Alexander Somov <somov at jlab.org> wrote:
>
>>
>>
>> Hi Colin,
>>
>> Could you update us on the status of bad (suspicious)
>> channels in the FCAL.
>>
>> Could you send a list of bad/suspicious channels
>>
>> Did you have a chance to replace bases during
>> this shut down ? How many spare bases do you have ?
>>
>> We'll need to take LED data when you turn HVs on.
>>
>> Thanks,
>>         Sasha
>>
>>
>
> -- 
> Colin Gleason
> Postdoctoral Fellow
> Indiana University
> Department of Physics
>