[Erd108] [EXTERNAL] Re: Draft of CPAD-2023 (11/7-11/10) talk

Wed Nov 8 09:57:57 EST 2023

Hi all,

  *   The contribution of the resistive layer in charge spread for Sourav prototypes (same as mine) is small (not negligible but not a factor here).  The surface resistivity is ~20MOhm/square according to Rui and with these devices even with 400 um. Unlike the development of resistive sharing readout at Saclay, the resistive layer here is not optimized for charge spread (because we are focused on 2D zigzag or capacitive-sharing options), so it the DLC helps a little but is not the main player. Even with a 400 um pitch uRWELL and 3 mm gap you barely get a cluster size more than 2 (barely}

  *   The main issue with Sourav chamber ==> the readout PCB is extremely noisy, it is badly designed. one reason is the fact that only half of the channel were connected to the APVs ==> as Alexander said, this is a common mode correction nightmare. I have a lot of experience with this situation and was able to correct it offline in the past with other detector, but it has to be done very carefully, if not, it will translate in high channel noise which I suspect is still the case to some extent. A second reason is that we still suspect that the PCB is very noisy regardless the common mode correction issue. My suspicion is that the design (traces and etc ...) is not optimal. The noise level is just awful.

  *   It is not correct to say that transverse diffusion is not important here (just compare 1 mm thing gap with 3 mm without capacitive-sharing or zigzag and you will quickly observed that the transverse diffusion is  as critical if not more critical to the charge sharing as the DLC contribution.

  *   With a 1.6 mm pitch zigzag readout, I still need someone to explain to me how you expect more than 2 strips event for a 1 mm thin gap detector unless you heavily rely on large spread by the resistive layer (which is not the case here). Sourav strip multiplicity plots makes all sense for me  from that point of view specially if you consider the noise level ==> mots events will be 1-strip cluster events.

Best regards
Kondo

From: Erd108 <erd108-bounces at jlab.org> On Behalf Of Maxence Vandenbroucke
Sent: Wednesday, November 8, 2023 5:37 AM
To: Tarafdar, Sourav <sourav.tarafdar at vanderbilt.edu>
Cc: erd108 at jlab.org
Subject: Re: [Erd108] [EXTERNAL] Re: Draft of CPAD-2023 (11/7-11/10) talk

Hi Sourav,

I’ve not followed the conversation in its entirety but just to say that in this case what is important is the layer between the resistive component and the readout electrode. The diffusion of the resistive layer happens there, so the distance between the DLC and the copper, and the permeability of the material, are going to be of importance in the effective cluster size. More precisely it’s the RC, but C dominates.

Best,

Maxence

On 8 Nov 2023, at 07:49, Tarafdar, Sourav <sourav.tarafdar at vanderbilt.edu<mailto:sourav.tarafdar at vanderbilt.edu>> wrote:

Hi Alexander,

The detector  (GEM + mRwell) itself had 1 mm drift gap and 0.5 mm transfer gap. The GEM + MMG has 1mm drift and 1 mm transfer gap. Both of them showed that mostly single strips were getting fired.  The transverse diffusion in KrCO2(80:20) at 2 kV/cm is 0.03 cm ½  . I think only relying on transverse diffusion of electrons will be probably misleading considering both the mRwell and MMG are resistive layer to aid in charge spread. I don’t have the exact number for the resistivity for these two layers at this moment. Electronics for all the prototypes were same but for the zigzag strips which has 128 strips (64 X + 64 Y) , 64 pins of one panasonic was used for X strips and 64 pins for second Panasonic was used for Y strips. Effectively half of the pins of each Panasonic was left floating causing more noise as compared to the other prototypes. It was not a good choice to decouple X-Y strips in two different connectors making the analysis more complex.

Best regards,
-Sourav

From: Kiselev, Alexander <ayk at bnl.gov<mailto:ayk at bnl.gov>>
Date: Tuesday, November 7, 2023 at 11:00 PM
To: Tarafdar, Sourav <sourav.tarafdar at vanderbilt.edu<mailto:sourav.tarafdar at vanderbilt.edu>>, erd108 at jlab.org<mailto:erd108 at jlab.org> <erd108 at jlab.org<mailto:erd108 at jlab.org>>
Subject: Re: Draft of CPAD-2023 (11/7-11/10) talk
  Hi Sourav,

  Well, the slide gives a hint that analysis is in progress, but in general it rather indicates that the readout just shows a poor performance (no charge sharing). Remind me please, what was the hybrid composition (and gaps in mm)? And what is the transverse diffusion coefficient  in all gaps for this mixture and V/cm values? More importantly, why common mode correction (and analysis procedure in general) face more difficulties than in the other cases? Sorry, I did not follow this development, but I thought the electronics setup was identical for all of these prototypes, except for the readout structure?

  Thank you,
    Alexander.

________________________________
From: Tarafdar, Sourav <sourav.tarafdar at vanderbilt.edu<mailto:sourav.tarafdar at vanderbilt.edu>>
Sent: Tuesday, November 7, 2023 8:13 PM
To: Kiselev, Alexander <ayk at bnl.gov<mailto:ayk at bnl.gov>>; erd108 at jlab.org<mailto:erd108 at jlab.org> <erd108 at jlab.org<mailto:erd108 at jlab.org>>
Subject: Re: Draft of CPAD-2023 (11/7-11/10) talk

Hi Alexander,

Thanks for the comments. I implemented the suggestions.
As per your questions on slide 10, the plots are for normal angle of track on 1 mm drift gap prototype. For that detector I haven’t yet gotten to the point of extracting residual as it needs extensive work on common mode correction. Work is still in progress on that front.

Best regards,
-Sourav

From: Kiselev, Alexander <ayk at bnl.gov<mailto:ayk at bnl.gov>>
Date: Tuesday, November 7, 2023 at 6:25 PM
To: BOSSU Francesco <francesco.bossu at cea.fr<mailto:francesco.bossu at cea.fr>>, Tarafdar, Sourav <sourav.tarafdar at vanderbilt.edu<mailto:sourav.tarafdar at vanderbilt.edu>>, erd108 at jlab.org<mailto:erd108 at jlab.org> <erd108 at jlab.org<mailto:erd108 at jlab.org>>
Subject: Re: Draft of CPAD-2023 (11/7-11/10) talk
  Hi Sourav,

  A nice set of slides. Please consider to correct or spell out the following:

  slide 3: "Si MAPS tracker" (to make it clear why timing resolution is poor)

  slide 6: BNL bullet should be "2D zigzag" rather than "2D capacitive sharing"
  slide 6: as a matter of fact none of the pitch numbers on the illustrations matches the actual prototype (was 1.35mm in both projections)
  slide 6: a "gap" artifact should probably be removed

  slide 7: well, this is not happening in 2024

  slide 9: "2D chevron" -> "2D zigzag"

  slide 10: for my understanding, the bottom right plot is a total number of strips per event? at which angle is this, and with what drift gap? are you getting reasonable residuals at 0 degrees, for 2&3-strip clusters?

  Cheers & good luck with the talk!
    Alexander.

________________________________
From: Erd108 <erd108-bounces at jlab.org<mailto:erd108-bounces at jlab.org>> on behalf of BOSSU Francesco <francesco.bossu at cea.fr<mailto:francesco.bossu at cea.fr>>
Sent: Tuesday, November 7, 2023 6:13 PM
To: Tarafdar, Sourav <sourav.tarafdar at vanderbilt.edu<mailto:sourav.tarafdar at vanderbilt.edu>>; erd108 at jlab.org<mailto:erd108 at jlab.org> <erd108 at jlab.org<mailto:erd108 at jlab.org>>
Subject: [Erd108] [EXTERNAL] Re: Draft of CPAD-2023 (11/7-11/10) talk

Dear Sourav

sorry for the late comments.

For the micromegas part, just two small suggestions.

You can update the CAD design (slide 4) with a recent one (attached)
On the next slide, you can change the 2d zigzag schema with the asacusa pattern (in attachment).
Also, if you want, you can add a picture of the beam test (attached)

cheers
Francesco
________________________________
From: Erd108 <erd108-bounces at jlab.org<mailto:erd108-bounces at jlab.org>> on behalf of Tarafdar, Sourav <sourav.tarafdar at vanderbilt.edu<mailto:sourav.tarafdar at vanderbilt.edu>>
Sent: 06 November 2023 19:06:07
To: erd108 at jlab.org<mailto:erd108 at jlab.org>
Subject: [Erd108] [EXTERNAL] Re: Draft of CPAD-2023 (11/7-11/10) talk

Dear all,

I uploaded the modified version of the slides after implementing comments from Kondo and Marcus. I am just waiting to get updated detector mechanics drawing from Pietro on slide 6.
If someone wants to see the slides from browser then suggestions is to open  the pdf version herehttps://drive.google.com/file/d/1xMW4bP1jkKIVmxjr1SOUa1gRoTd9lji8/view?usp=sharing<https://urldefense.proofpoint.com/v2/url?u=https-3A__drive.google.com_file_d_1xMW4bP1jkKIVmxjr1SOUa1gRoTd9lji8_view-3Fusp-3Dsharing&d=DwMGaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=6nBhCQ9asnI7Gb72jBWQ4g&m=BHZejW_VHb9Q71o7S-mlLGoen-4fy_9oIRXGOF2D_BWKm0S9LARltW1HokCHfvA-&s=Bhl_pPqaVPCV5weH78bL1b_vvshdd5fPUoAUAsIUAzM&e=>

The ppt vesrion is here https://urldefense.proofpoint.com/v2/url?u=https-3A__docs.google.com_presentation_d_1S6Dxlu5LS8ji9l32U6tK5iLJwlsRTjyX_edit-3Fusp-3Ddrive-5Flink-26ouid-3D113597179804759540761-26rtpof-3Dtrue-26sd-3Dtrue&d=DwIGaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=6nBhCQ9asnI7Gb72jBWQ4g&m=Jz_Ia-2xld3sVA9UeiUlA7LE7GkFoWKMcM-NIxupia0G0uZzB8GgSBQjeX8tRBuX&s=-Nexz-cMKJ_7bZqo7uC1VqhNLBCfYlp_8UAabgezD-w&e= <https://urldefense.proofpoint.com/v2/url?u=https-3A__docs.google.com_presentation_d_1S6Dxlu5LS8ji9l32U6tK5iLJwlsRTjyX_edit-3Fusp-3Ddrive-5Flink-26ouid-3D113597179804759540761-26rtpof-3Dtrue-26sd-3Dtrue&d=DwMGaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=6nBhCQ9asnI7Gb72jBWQ4g&m=BHZejW_VHb9Q71o7S-mlLGoen-4fy_9oIRXGOF2D_BWKm0S9LARltW1HokCHfvA-&s=-45W9WQ6VbMzVa6zRHxyNTPShTeJVGpyErjJmEI8SsY&e=>

Thanks,
-Sourav

From: Tarafdar, Sourav <sourav.tarafdar at vanderbilt.edu<mailto:sourav.tarafdar at vanderbilt.edu>>
Date: Monday, November 6, 2023 at 10:10 AM
To: Gnanvo, Kondo (kg6cq) <kg6cq at virginia.edu<mailto:kg6cq at virginia.edu>>
Cc: erd108 at jlab.org<mailto:erd108 at jlab.org> <erd108 at jlab.org<mailto:erd108 at jlab.org>>
Subject: Re: Draft of CPAD-2023 (11/7-11/10) talk
Hi Kondo,
Sure, will do that. Thank you for bringing that to my attention.
Thanks,
-Sourav

On Nov 6, 2023, at 9:23 AM, Gnanvo, Kondo (kg6cq) <kg6cq at virginia.edu<mailto:kg6cq at virginia.edu>> wrote:

Hi Sourav
Please also add this reference on slide 6 underneath the cartoon of capacitive-sharing RO

K. Gnanvo et al., NIM A, 1047 (2023) 167782

Thanks
Kondo

From: Erd108 <erd108-bounces at jlab.org<mailto:erd108-bounces at jlab.org>> On Behalf Of Tarafdar, Sourav
Sent: Sunday, November 5, 2023 1:36 PM
To: erd108 at jlab.org<mailto:erd108 at jlab.org>
Subject: [Erd108] [EXTERNAL] Draft of CPAD-2023 (11/7-11/10) talk

Dear all,

Sorry for the delay but attached is the draft of my CPAD -2023 talk. The talk is scheduled for 11/8/2023.  It is 15 (12+3) minutes talk. Effectively I will prefer to limit the number of slides to 14.
Here is the  abstract https://urldefense.proofpoint.com/v2/url?u=https-3A__indico.slac.stanford.edu_event_8288_contributions_7884_&d=DwIGaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=6nBhCQ9asnI7Gb72jBWQ4g&m=Jz_Ia-2xld3sVA9UeiUlA7LE7GkFoWKMcM-NIxupia0G0uZzB8GgSBQjeX8tRBuX&s=CEgnzsF1xyAvlGwUGkHIRrMzYFOjv3XhQsajC-x3Zvw&e= <https://urldefense.proofpoint.com/v2/url?u=https-3A__indico.slac.stanford.edu_event_8288_contributions_7884_&d=DwMFAg&c=CJqEzB1piLOyyvZjb8YUQw&r=6nBhCQ9asnI7Gb72jBWQ4g&m=FOKWrsPPVBb5Ws8ShBIf8yK8t0f_ByFpZDMVepxGV_fskiiyLJCqQu68QHF5bfJP&s=Ei85LJOTAcwgnqnxIQCznGR0Ged1YHzJIKYFLXhMrFc&e=>  and timetablehttps://indico.slac.stanford.edu/event/8288/sessions/586/#20231108<https://urldefense.proofpoint.com/v2/url?u=https-3A__indico.slac.stanford.edu_event_8288_sessions_586_-2320231108&d=DwMFAg&c=CJqEzB1piLOyyvZjb8YUQw&r=6nBhCQ9asnI7Gb72jBWQ4g&m=FOKWrsPPVBb5Ws8ShBIf8yK8t0f_ByFpZDMVepxGV_fskiiyLJCqQu68QHF5bfJP&s=ewo_yspSItQBhkvxat7EcGRSwh_c3ED0-_2K4P6xzq0&e=> .

Any comments and suggestions are most welcome.

Thanks,
-Sourav
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Maxence Vandenbroucke, PhD

Université Paris-Saclay
CEA Saclay
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