[Sbs_gems] [EXTERNAL] Fwd: Cosmic data for UV Layer and J1

Fri Nov 5 15:08:36 EDT 2021

Hi All,

Sorry for the extra confusion. I should also add that the UV GEM
transformation was never done properly in these low level plots, and by the
time we realized it Andrew had already written the analyzer correctly. So
we stopped using these plots at meetings and have forgotten about them,
until now. But the UV dimensions are definitely not correctly set in the
low level plots, and I have never had time to figure out where the error
is. For our purposes the maps can just qualitatively tell us where the dead
areas are. I apologize for the confusion, I know this is a bad excuse.

Best,
Sean

On Fri, Nov 5, 2021 at 3:04 PM Andrew Puckett <puckett at jlab.org> wrote:

> Is the short dimension of the active area really just +/- 170 mm or so? I
> thought it was supposed to be 40 cm
>
>
>
> *From: *Sbs_gems <sbs_gems-bounces at jlab.org> on behalf of Sean Jeffas <
> sj9ry at virginia.edu>
> *Date: *Friday, November 5, 2021 at 3:02 PM
> *To: *Liyanage, Nilanga K (nl8n) <nl8n at virginia.edu>
> *Cc: *sbs_gems at jlab.org <sbs_gems at jlab.org>
> *Subject: *Re: [Sbs_gems] [EXTERNAL] Fwd: Cosmic data for UV Layer and J1
>
> Hi Nilanga,
>
>
>
> This is the edge of the active area. The size of the graph is larger than
> the actual active area. The hits outside of the active area are just noise
> that got reconstructed improperly. Normally we do not see this with an XY
> GEM because in that coordinate system even fake hits must fall inside the
> active area. But if we have a 2D correlation that is not real in the UV GEM
> then it is possible for that to get reconstructed in an impossible
> position. This is because of the UV geometry. Hence why only UV GEMs will
> have noise that shows up outside of the active area.
>
>
> Best,
> Sean
>
>
>
> On Fri, Nov 5, 2021 at 2:55 PM Liyanage, Nilanga K (nl8n) <
> nl8n at virginia.edu> wrote:
>
> Hi Sean
>
>
>
> Yes, may be the mapping is correct.
>
>
>
> But I have a question: What gives rise to the  drop along the sharp
> straight lines at roughly + and - 160 mm ? Is it the trigger scintillator ?
>
>
>
> Best
>
>
>
> Nilanga
>
>
>
>
> ------------------------------
>
> *From:* Sbs_gems <sbs_gems-bounces at jlab.org> on behalf of Sean Jeffas <
> sj9ry at virginia.edu>
> *Sent:* Friday, November 5, 2021 2:15 PM
> *To:* Gnanvo, Kondo (kg6cq) <kg6cq at virginia.edu>
> *Cc:* sbs_gems at jlab.org <sbs_gems at jlab.org>
> *Subject:* Re: [Sbs_gems] [EXTERNAL] Fwd: Cosmic data for UV Layer and J1
>
>
>
> Hi All,
>
>
>
> Here are the results using 2 hit minimum clusters. I think the UV GEM
> mapping looks fine. However there are a lot of areas with missing strips
> adding up (I count at least 7 areas). It looks to be about 5-10% of the
> active area in missing strips. Since we have time, as Bogdan suggests, I
> will try to fix as many as I can.
>
>
>
> Best,
>
> Sean
>
>
>
> On Fri, Nov 5, 2021 at 1:56 PM Gnanvo, Kondo (kg6cq) <kg6cq at virginia.edu>
> wrote:
>
> Hi Sean,
>
> Maybe you are right, but please double-check carefully without assumption
> that just because you duplicate the same mapping for the other chambers,
> that you got all your mapping right.
>
>
>
> I see a lot of patterns in both 2D hit map and 1D hit distribution that
> make me suspect that there is a mapping issue, though I am not prepare to
> bet my life on this
>
>
>
> Best regards
>
> Kondo
>
>
>
> *From:* Sean Jeffas <sj9ry at virginia.edu>
> *Sent:* Friday, November 5, 2021 1:48 PM
> *To:* Gnanvo, Kondo (kg6cq) <kg6cq at virginia.edu>
> *Cc:* Ezekiel Wertz <ewertz at email.wm.edu>; sbs_gems at jlab.org
> *Subject:* Re: [Sbs_gems] [EXTERNAL] Fwd: Cosmic data for UV Layer and J1
>
>
>
> Hi Kondo,
>
>
>
> The UV layer does not have a mapping problem. It is an exact copy of the
> mapping from BB, which is proven to be correct. I believe the pattern and
> all the hits outside the active area are just noisy strips that cause bad
> 2D correlations, since this is a low level analysis and does not have
> tracking to check that hits are true. Also notably, I just realized this is
> an old version that accepts 1 strip clusters, which certainly also
> contributes a lot to the noise that we see. It may be worth it to rerun
> with 2 hit minimum clusters.
>
>
>
> For the UV data, I see there are some strips missing, and an entire APV on
> the right most side. I looked at the GEM yesterday and did not see anything
> disconnected, and also the raw APV data did not show me that the APV was
> bad. So I am not sure if it is possible to fix all these missing strips. If
> we have time I can try replacing some APVs, but it will likely end up being
> more work than it is worth. Also I will note that the large missing area
> from one APV on the right side correspond to the top of the GEM, and would
> therefore be outside of the production cross section anyway.
>
>
>
> Best,
>
> Sean
>
>
>
> On Fri, Nov 5, 2021 at 1:26 PM Gnanvo, Kondo (kg6cq) <kg6cq at virginia.edu>
> wrote:
>
> Hi Zeke,
>
> I don’t think it is a big deal. Sean or John will probably fix it quickly
>
> Thanks
>
> Kondo
>
>
>
> *From:* Ezekiel Wertz <ewertz at email.wm.edu>
> *Sent:* Friday, November 5, 2021 1:24 PM
> *To:* Gnanvo, Kondo (kg6cq) <kg6cq at virginia.edu>
> *Cc:* sbs_gems at jlab.org
> *Subject:* Re: [Sbs_gems] [EXTERNAL] Fwd: Cosmic data for UV Layer and J1
>
>
>
> Hi Kondo,
>
>
>
> I am not as familiar with the UV layer mapping. So I'll talk to Sean about
> this. I'll also do some comparison with the BB UV layer mappings.
>
>
>
> Zeke
>
>
>
> On Fri, Nov 5, 2021 at 1:19 PM Gnanvo, Kondo (kg6cq) <kg6cq at virginia.edu>
> wrote:
>
> Hi Zeke,
>
> That is great. Thanks for these first results.
>
> It looks to me that there is a mapping problem with the UV layer.
>
> Please have a look at the pattern of the 2D hit map. Just a minor issue
>
>
>
> Best regards
>
> Kondo
>
>
>
> *From:* Sbs_gems <sbs_gems-bounces at jlab.org> *On Behalf Of *Ezekiel Wertz
> *Sent:* Friday, November 5, 2021 1:11 PM
> *To:* sbs_gems at jlab.org
> *Subject:* [Sbs_gems] [EXTERNAL] Fwd: Cosmic data for UV Layer and J1
>
>
>
>
>
> ---------- Forwarded message ---------
> From: *Ezekiel Wertz* <ewertz at email.wm.edu>
> Date: Fri, Nov 5, 2021 at 11:47 AM
> Subject: Cosmic data for UV Layer and J1
> To: <sbs_gem at jlab.org>
>
>
>
> Hi GEM folks,
>
>
>
> Attached you will find cosmic data and plots for the UV layer and J1.
> Taking cosmic data on the UV layer was priority, but we managed to get INFN
> J1 running as well. We took this data earlier this week. There were about
> 500,000 events.
>
>
>
> Other than a few strips that look not great, it looks like the UV layer is
> performing fairly well. Maybe Sean, Anu, or John has more to say about
> that.
>
>
>
> In regards to J1, each module on this layer has 2 shorted sectors. Which
> we see fairly clearly. However, there is a missing APV on the middle
> module. This was disabled because of connection problems that have since
> been better  understood. The top module has a partial or almost missing
> APV, this connection has since been remedied but needs to be checked. So
> this APV on the middle module is the last major thing that needs to be
> resolved for J1. There are some strips on the top and middle module that
> are partial and it needs to be understood if those are bad strips or
> partially disconnected APVs.
>
>
>
> So again the main result for this is the UV layer. But this is also a good
> starting place for J1. Also take note that the empty plots are simply
> because this plotting macro was not adjusted for 2 layers instead of 5.
>
>
>
> Best,
>
> Zeke
>
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