[Sbs_gems] [EXTERNAL] UV Layer 4 Overview

Mon Dec 6 11:15:02 EST 2021

Hi all,

Zeke and I are looking at J3, and it could probably be ready at the latest by early next week. We will send around some cosmic updates tomorrow or Wednesday to discuss, but we should also discuss at some point if the desire is to replace J0 with J3 or a UV layer. It will strongly dictate manpower efforts.

At this point, it’s not clear to me what our strategy is: Do we want to get a working layer in asap? Or do we want to wait a couple weeks to put in a UV layer?

Thanks,
Holly

From: Sbs_gems <sbs_gems-bounces at jlab.org> on behalf of Anuruddha Rathnayake <adr4zs at virginia.edu>
Date: Saturday, December 4, 2021 at 6:55 PM
To: Sean Jeffas <sj9ry at virginia.edu>
Cc: "sbs_gems at jlab.org" <sbs_gems at jlab.org>
Subject: Re: [Sbs_gems] [EXTERNAL] UV Layer 4 Overview

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<mailto: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<mailto: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<mailto: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<mailto: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<mailto:sbs_gems-bounces at jlab.org>> on behalf of Gnanvo, Kondo (kg6cq) <kg6cq at virginia.edu<mailto:kg6cq at virginia.edu>>
Sent: Friday, December 3, 2021 4:43 PM
To: Jeffas, Sean (sj9ry) <sj9ry at virginia.edu<mailto:sj9ry at virginia.edu>>; sbs_gems at jlab.org<mailto:sbs_gems at jlab.org> <sbs_gems at jlab.org<mailto: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<mailto:sbs_gems-bounces at jlab.org>> on behalf of Sean Jeffas <sj9ry at virginia.edu<mailto:sj9ry at virginia.edu>>
Sent: Friday, December 3, 2021 4:35 PM
To: sbs_gems at jlab.org<mailto:sbs_gems at jlab.org> <sbs_gems at jlab.org<mailto: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
_______________________________________________
Sbs_gems mailing list
Sbs_gems at jlab.org<mailto:Sbs_gems at jlab.org>
https://mailman.jlab.org/mailman/listinfo/sbs_gems
_______________________________________________
Sbs_gems mailing list
Sbs_gems at jlab.org<mailto:Sbs_gems at jlab.org>
https://mailman.jlab.org/mailman/listinfo/sbs_gems
_______________________________________________
Sbs_gems mailing list
Sbs_gems at jlab.org<mailto:Sbs_gems at jlab.org>
https://mailman.jlab.org/mailman/listinfo/sbs_gems
_______________________________________________
Sbs_gems mailing list
Sbs_gems at jlab.org<mailto:Sbs_gems at jlab.org>
https://mailman.jlab.org/mailman/listinfo/sbs_gems
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mailman.jlab.org/pipermail/sbs_gems/attachments/20211206/91df34fe/attachment-0001.html>