[Sbs_gems] [EXTERNAL] UV Latency Analysis Results

Sun Jan 16 01:50:55 EST 2022

EDIT:

The first image included inside the text, showing efficiency for UV Layer 1
should be replaced with this plot:

[image: 13297 Layer 1 Efficiency.png]

My apologies, I previously and erroneously attached the plots for UV Layer
0 instead of UV Layer 1.

Best,

John

On Sun, Jan 16, 2022 at 1:45 AM John Boyd <jab7bp at virginia.edu> wrote:

> So, at the current moment, for the initial runs at 1 uA, I only had access
> to 10k replays so I based the following off of those.
>
> The differences between the two runs are that Run 13297 had previous
> voltage values and Run 13298 had an increase of 25V on UV Layer 1 and
> Module 1 of the XY Layer.
>
> From the attached plots showing the peak time samples, it appears that the
> latency was okay and therefore I didn't adjust it.
>
>
> [image: image.png] [image: 13297 Layer 3 Latency.png]
> [image: 13299 Layer 1 Latency.png] [image: 13299 Layer 3 - Latency.png]
>
> --------------------------------------------------------------------------------------------------------------------------------------------------------
>
>
> Also, between the two HV settings there isn't a definite enough difference
> (increase) in efficiencies between the previous voltage settings and from
> increasing them by 25V. Please see the attached plots for this.
>
>
> [image: 13297 Layer 1 Efficiency.png] [image: 13297 XY GEM1
> Efficiency.png]
> [image: 13299 Layer 1 Efficiency.png] [image: 13299 XY GEM1
> Efficiency.png]
>
> --------------------------------------------------------------------------------------------------------------------------------------------------------
>
>
> With that being said, I left the voltages for UV Layer 1 and Module 1 of
> the XY layer set with an increase of 25V.
>
> While I was writing this one of the 50k replays finally came in and for
> reference the efficiency for UV Layer 1 with the 25V increase was: 84.71 ±
>  0.64. The full set of 50k replays is not yet finished. I will update if
> those change anything.
>
> Best regards,
>
> John Boyd
>
>
>
>
>
> On Sat, Jan 15, 2022 at 11:45 AM Gnanvo, Kondo (kg6cq) <kg6cq at virginia.edu>
> wrote:
>
>> Hi again Sean,
>>
>> I also thing that like Andrew suggested, ultimately, changing the latency
>> for these two layers 1 & 3 to center the APV25 peak for the hits in the
>> central area of the detector will address the concern (tracking efficiency)
>>
>> Best regards
>>
>> Kondo
>>
>>
>>
>> *From:* Sbs_gems <sbs_gems-bounces at jlab.org> *On Behalf Of *Sean Jeffas
>> *Sent:* Saturday, January 15, 2022 11:02 AM
>> *To:* Sbs_gems at jlab.org
>> *Subject:* Re: [Sbs_gems] [EXTERNAL] UV Latency Analysis Results
>>
>>
>>
>> Hi All,
>>
>>
>>
>> We have finished analyzing a cosmic test after turning the gas flow down
>> on layers 1 and 3 from 525 cc/min to 375. The data is attached below. For
>> reference:
>>
>>
>>
>> *Run 13240: *Taken January 11th with all four UV layers and 2 uA on LH2
>> at the SBS-14 kinematic. Gas flow at 525 cc/min
>>
>> *Run 12423:* Taken January 14th with cosmic data. UV layers 1 and 3 gas
>> flowing at 375 cc/min
>>
>>
>>
>> These runs are a bit difficult to compare since one is with beam and the
>> other is comsic, but it's all that we have. Overall you can see that the
>> timing distribution is a bit better for layer 1 and 3, but still not great.
>> Also the efficiencies and gains are not significantly reduced by the lower
>> gas flow. So I think we can run with this setting.
>>
>>
>>
>> Kondo/Nilanga/Xinzhan: Will this reduced gas flow have a greater effect
>> with the beam on? I suppose we will find out in two hours anyway.
>>
>>
>>
>> Also I would be interested in turning up the voltage on layer 1 and
>> module 1 in the XY layer by 25 V. Are there any objections?
>>
>>
>>
>> Best,
>> Sean
>>
>>
>>
>> On Thu, Jan 13, 2022 at 3:49 PM Sean Jeffas <sj9ry at virginia.edu> wrote:
>>
>> Hi Andrew,
>>
>>
>>
>> I am not sure if you meant to only reply to only me, but here are the
>> plots you asked for. I actually already had them but decided it was kind of
>> overkill.
>>
>>
>>
>> Best,
>>
>> Sean
>>
>>
>>
>> On Thu, Jan 13, 2022 at 3:21 PM Andrew Puckett <puckett at jlab.org> wrote:
>>
>> Hi Sean,
>>
>>
>>
>> Interesting results. Another interesting way to visualize these results
>> would be in terms of the strip mean times, which might (or might not) have
>> somewhat better resolution than the time sample peaking distribution. I
>> would also be curious to see a couple of alternative ways of visualizing
>> the data. For example:
>>
>>
>>
>>    1. A more “binary” approach: 1D and 2D distributions vs. x and/or y
>>    for hits peaking in sample 5 and for hits NOT peaking in sample 5
>>    2. Same as 1, but perhaps broken out by hits peaking in samples 1, 2,
>>    3, 4, 5, etc.
>>
>>
>>
>> Cheers,
>>
>> Andrew
>>
>>
>>
>>
>>
>>
>>
>> *From: *Sbs_gems <sbs_gems-bounces at jlab.org> on behalf of Sean Jeffas <
>> sj9ry at virginia.edu>
>> *Date: *Thursday, January 13, 2022 at 3:03 PM
>> *To: *Sbs_gems at jlab.org <sbs_gems at jlab.org>
>> *Subject: *[Sbs_gems] [EXTERNAL] UV Latency Analysis Results
>>
>> Hi All,
>>
>>
>>
>> I have finished analyzing the spatial distribution of the peak time
>> samples. I have attached the results below for two runs.
>>
>>
>>
>> *Run 13240: *Taken January 11th with all four UV layers and 2 uA on LH2
>> at the SBS-14 kinematic.
>>
>> *Run 12423:* Taken December 1st with J0 still in the layer 1 position
>> but the UV layer was in layer 3 position. This was 2 uA on LD2 at SBS-11.
>>
>>
>>
>> In the recent run (13240) you can clearly see the peak time sample is
>> uniform over the hit map for every layer except for layer 1 and layer 3.
>> Similarly if you look at the December run (12423) the same issue was
>> present in layer 3, but we never noticed it because we were always the
>> first and last bin out of the analysis. John and I measured the resistors
>> on the GEMs today and did not find a resistance that would suggest that the
>> gas window has collapsed onto the cathode. Unfortunately the shielding
>> blocks us from seeing the gas window, otherwise it would be very easy to
>> tell.
>>
>>
>>
>> Therefore our current conclusion is that since the GEM layers 1 and 3
>> both have a non uniform gas flow, this is probably causing some bend in the
>> readout board, which causes this issue. To fix this we can turn down the
>> gas flow rate and see how everything is affected. Since the experiment is
>> down for a few days it would be good to turn it down today and take some
>> cosmic data, if possible.
>>
>>
>>
>> Best,
>>
>> Sean
>>
>> _______________________________________________
>> Sbs_gems mailing list
>> 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/20220116/2877725f/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image.png
Type: image/png
Size: 286338 bytes
Desc: not available
URL: <https://mailman.jlab.org/pipermail/sbs_gems/attachments/20220116/2877725f/attachment-0009.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 13297 Layer 3 Latency.png
Type: image/png
Size: 304142 bytes
Desc: not available
URL: <https://mailman.jlab.org/pipermail/sbs_gems/attachments/20220116/2877725f/attachment-0010.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 13299 Layer 1 Latency.png
Type: image/png
Size: 271178 bytes
Desc: not available
URL: <https://mailman.jlab.org/pipermail/sbs_gems/attachments/20220116/2877725f/attachment-0011.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 13299 Layer 3 - Latency.png
Type: image/png
Size: 1089899 bytes
Desc: not available
URL: <https://mailman.jlab.org/pipermail/sbs_gems/attachments/20220116/2877725f/attachment-0012.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 13297 Layer 1 Efficiency.png
Type: image/png
Size: 175215 bytes
Desc: not available
URL: <https://mailman.jlab.org/pipermail/sbs_gems/attachments/20220116/2877725f/attachment-0013.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 13297 XY GEM1 Efficiency.png
Type: image/png
Size: 165606 bytes
Desc: not available
URL: <https://mailman.jlab.org/pipermail/sbs_gems/attachments/20220116/2877725f/attachment-0014.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 13299 Layer 1 Efficiency.png
Type: image/png
Size: 176801 bytes
Desc: not available
URL: <https://mailman.jlab.org/pipermail/sbs_gems/attachments/20220116/2877725f/attachment-0015.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 13299 XY GEM1 Efficiency.png
Type: image/png
Size: 164158 bytes
Desc: not available
URL: <https://mailman.jlab.org/pipermail/sbs_gems/attachments/20220116/2877725f/attachment-0016.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 13297 Layer 1 Efficiency.png
Type: image/png
Size: 175815 bytes
Desc: not available
URL: <https://mailman.jlab.org/pipermail/sbs_gems/attachments/20220116/2877725f/attachment-0017.png>