[Sbs_gems] [EXTERNAL] UV Layer 4 Overview

Sat Dec 4 18:55:19 EST 2021

Hi All,

I can update early next week about the time line of getting the 3 slot back
planes ready once I hear back from Chris Cuevas.

Best
Anu

On Sat, 4 Dec 2021, 18:07 Sean Jeffas, <sj9ry at virginia.edu> wrote:

> Hi All,
>
> Kondo: Actually we will not need to remove any UV layers from BB to do
> this work. Recall that we can slide the layers horizontally on the frame.
> We utilize this to replace the 4-slot backplanes with 3-slot backplanes
> with probably 5 hours of work in the hall. Also we do not need to wait
> until the new batch of APVs arrive. We can take the APVs from the current
> SBS setup, if we deem that this is critical to do. So here is the list of
> tasks necessary to get UV layer 4 installed into INFN J0's place.
>
> *Tasks:*
> Electronics group fixes the 3-slot BPs:* I have no idea how long this
> will take. We will need Anu to update. This may be a bottleneck.*
> Test the 3-slot BPs in EEL: ~5 hours
> Place the 3-slot BPs in the three UV GEMs in BB: ~5 hours of work in the
> hall
> Assemble UV layer 4 with the frame, and all electronics: *Zeke says he
> does not think there are any spare INFN carbon fiber frames. If we have to
> make new frame this may be the bottleneck. Is it worth disassembling an
> INFN layer, like J2, just to use the frame for UV?*
> Flow gas through UV layer and do a HV test: ~3 days
> Cosmic test in the INFN test lab: 2 days
> Swap the layer with J0: ~8 hours.
>
> *Total: *About 1-2 weeks, if we ignore my comments on things I do not
> know.
>
> *Overview:*
> Assuming everything goes perfectly, and my comments on things I do not
> know are all simple solutions, then we could complete the work by Dec 21st.
> We would need at least 4 people working on this all day every day. Given
> the unknowns and the fact that disturbing all UV layers in BB may cause
> more issues I think it is extremely unlikely that this is possible by Dec
> 21st. But I will let Anu and Zeke comment, or if anyone else has any ideas.
> Overall replacing J0 with another INFN layer will be significantly easier.
>
> Best,
> Sean
>
> On Fri, Dec 3, 2021 at 6:20 PM Thir Gautam <tns.gautam at gmail.com> wrote:
>
>> Hi Anu and all,
>>
>> There are 25 APV cards outside of 9th layer. Those APV cards are not
>> tested yet. I believe that there are 20-25 APV cards on the 9th layer.
>> Before getting Nilanga’s ordered we won’t have enough cards to populate a
>> new uv layer.
>>
>> Regards,
>>
>> Thir
>>
>> Sent from my iPhone
>>
>> On Dec 3, 2021, at 5:12 PM, Anuruddha Rathnayake <adr4zs at virginia.edu>
>> wrote:
>>
>> 
>> Hi Nilanga,
>>
>> Yes I am working on getting both of the fixes ready with Chris as soon as
>> possible.
>>
>> Layer 9 for GEn-RP  (which is the only one that has not been put on the
>> GEn-RP production frames) already donated 60 APVs for the 3rd UV layer. We
>> can take the rest out of it too if necessary. Thir might be able to give a
>> number on how many good APVs we have outside of that layer.
>>
>> Best,
>> Anu
>>
>>
>> On Fri, Dec 3, 2021 at 4:48 PM Liyanage, Nilanga K (nl8n) <
>> nl8n at virginia.edu> wrote:
>>
>>> Hi Sean, Kondo
>>>
>>> Anuruddha is contacting  Chris Cuevas about getting the 3-slot back
>>> planes fixed/
>>>
>>> Anuruddha: I am assuming that the adapters to flip the wire order in the
>>> cables are also being prepared, right ?
>>>
>>> We hope to get the APV cards in the next week or so
>>>
>>> Best
>>>
>>> Nilanga
>>> ------------------------------
>>> *From:* Sbs_gems <sbs_gems-bounces at jlab.org> on behalf of Gnanvo, Kondo
>>> (kg6cq) <kg6cq at virginia.edu>
>>> *Sent:* Friday, December 3, 2021 4:43 PM
>>> *To:* Jeffas, Sean (sj9ry) <sj9ry at virginia.edu>; sbs_gems at jlab.org <
>>> sbs_gems at jlab.org>
>>> *Subject:* Re: [Sbs_gems] [EXTERNAL] UV Layer 4 Overview
>>>
>>> Hi Sean,
>>> Yes, you are right. I forgot that the 4-slots backplanes were designed
>>> only for the UV layers, I don’t think removing them from the layers on BB
>>> and replace it with 3-slot is ever going to be an option for the current
>>> run up to end January. In addition to the lack of APV cards,  the 4th
>>> UV layer is out of the picture at least for now
>>>
>>> Best regards
>>> Kondo
>>>
>>> ------------------------------
>>> *From:* Sbs_gems <sbs_gems-bounces at jlab.org> on behalf of Sean Jeffas <
>>> sj9ry at virginia.edu>
>>> *Sent:* Friday, December 3, 2021 4:35 PM
>>> *To:* sbs_gems at jlab.org <sbs_gems at jlab.org>
>>> *Subject:* [Sbs_gems] [EXTERNAL] UV Layer 4 Overview
>>>
>>> Hi All,
>>>
>>> I just wanted to elaborate on the situation on the 4th UV layer, which
>>> is sitting in EEL and waiting as a spare. Each UV layer uses 12 4-slot
>>> backplanes and 4 3-slot backplanes. The 3-slot BPs are defective so we are
>>> using 4-slot BPs in their place. That means that for the three UV layers in
>>> BB right now we have used up every single 4-slot BP. Therefore we do not
>>> have the BPs to equip UV layer 4 to use as a replacement for anything.
>>>
>>> I am not familiar with the fixes needed for the 3-slot BPs, but assuming
>>> this is easy and can be done quickly, we still need to recover the 4-slot
>>> BPs from the UV GEMs in BB. This can probably be done by sliding the GEMs
>>> to the side in the BB frame, as we have done before, so we can reach them.
>>> Then we would need to place all the 3-slot BPs on the UV GEMs and test
>>> them. I would estimate we would need 2 days of downtime in the hall for
>>> this. Then we would need to add all the electronics to UV layer 4 back in
>>> EEL, and get it ready in one of the INFN frames and do a cosmic test on it.
>>> Then we would need another day of down time to swap it with J0 in the hall
>>> as we did with J2 earlier.
>>>
>>> Overall I think it would take two weeks of work to do all of this. Again
>>> I am completely assuming the fix to the 3-slot BPs is easy, I have no idea.
>>> Maybe Anu can elaborate. Also we will have to wait until the new APVs
>>> arrive to start any of this work. Between all of this and the holiday break
>>> I don't see this layer being used for anything during this run group.
>>>
>>> Also as a side note, I will have to dig through some old emails and
>>> notes, but I am fairly certain we accounted for all APVs and there are not
>>> enough to equip all 10 UVa SBS layers and 4 UV layers.
>>>
>>> Best,
>>> Sean
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