<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-7">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<!--[if !mso]><style>v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
</style><![endif]--><style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman",serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:#0563C1;
text-decoration:underline;}
p.xmsonormal, li.xmsonormal, div.xmsonormal
{mso-style-name:x_msonormal;
margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
span.EmailStyle24
{mso-style-type:personal-compose;
font-family:"Calibri",sans-serif;
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="FR" link="#0563C1" vlink="#954F72">
<div class="WordSection1">
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US">Dear Rolf, Elke, Silvia, John
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US">Thanks for the summary of the Outer uRWELL tracker meeting and the very productive discussion on the option and path forward.
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US">We had a follow up discussion on the matter at our eRD108 meeting.
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US">We agree that the suggestion / recommendation to start a parallel E&D effort that focused on the “common” mechanical structure design
for 3 prototypes (standard 3 mm gap, single amplification thin gap and hybrid amplification thin gap) is the best approach and would not result in additional delay as it maintains the standard 3 mm gap uRWELL as a reference (i.e. backup solution) that would
not require additional E&D. <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US">To illustrate why we are confident that hybrid thin-gap is compatible with the mechanical support structure of a standard gap uRWELL,
I prepared a few slides witj the cartoon cross sectional views of the 3 detector options showing a breakdown of the different elements of the mechanical support.
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US">You could see that with this design, when going from single amplification to hybrid amplification with GEM, the only additional elements
are the GEM foil and the induction gap frame. But most importantly, the “cathode block” is used as support structure of the GEM during the assembly (stretching and gluing) and is strong enough to sustain the tension of the stretched GEM foil (which is the
only stretched foil). <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US">The uRWELL-RO block which remain the same all 3 designs, will also help maintain further the tension of the stretched GEM foil in the
hybrid thin gap case<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US">In addition, we are thinking of some very simple and straightforward ideas (see backup slides) to reinforce the overall mechanical structure
of the detectors at no additional R&D cost and delay. <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US">If this slides help clarifies some of the concerns regarding the hybrid options and you are ok with the approach, then we are ready
to start follow up meetings on specific mechanical support design. <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US">Best regards
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US">Kondo
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<div>
<div style="border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif"> Rolf Ent <ent@jlab.org>
<br>
<b>Sent:</b> Monday, October 2, 2023 10:38 AM<br>
<b>To:</b> Aschenauer, Elke <elke@bnl.gov>; Brian Eng <beng@jlab.org>; Kondo Gnanvo <kagnanvo@jlab.org>; Francesco Bossu <francesco.bossu@cea.fr>; maxence.vandenbroucke <maxence.vandenbroucke@cea.fr>; Ernst Sichtermann <epsichtermann@lbl.gov>; Matthew Posik
<posik@temple.edu>; Lajoie, John G [PHYSA] <lajoie@iastate.edu>; Silvia Dalla Torre <silvia.dallatorre@cern.ch><br>
<b>Subject:</b> Re: MPGD: The Path forward<o:p></o:p></span></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<p class="MsoNormal"><span style="font-family:"Calibri",sans-serif;color:black">Dear all,<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-family:"Calibri",sans-serif;color:black"><o:p> </o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-family:"Calibri",sans-serif;color:black">attached a summary of the MPGD: Path Forward meeting that we had in last week's Thursday<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-family:"Calibri",sans-serif;color:black">tracking WG slot. It folds in comments by Elke, Silvia and me, and a question John had. There<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-family:"Calibri",sans-serif;color:black">are some action items. Hopefully we can soon have a follow-up as we have to get this in motion.<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-family:"Calibri",sans-serif;color:black"><o:p> </o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-family:"Calibri",sans-serif;color:black">Thanks to all for the constructive (long) meeting last Thursday.<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-family:"Calibri",sans-serif;color:black"><o:p> </o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-family:"Calibri",sans-serif;color:black">Best regards, Rolf<o:p></o:p></span></p>
</div>
<div class="MsoNormal" align="center" style="text-align:center">
<hr size="2" width="98%" align="center">
</div>
<div id="divRplyFwdMsg">
<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:black">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:black"> Aschenauer, Elke <<a href="mailto:elke@bnl.gov">elke@bnl.gov</a>><br>
<b>Sent:</b> Wednesday, September 20, 2023 5:38 AM<br>
<b>To:</b> Brian Eng <<a href="mailto:beng@jlab.org">beng@jlab.org</a>>; Kondo Gnanvo <<a href="mailto:kagnanvo@jlab.org">kagnanvo@jlab.org</a>>; Francesco Bossu <<a href="mailto:francesco.bossu@cea.fr">francesco.bossu@cea.fr</a>>; maxence.vandenbroucke <<a href="mailto:maxence.vandenbroucke@cea.fr">maxence.vandenbroucke@cea.fr</a>>;
Rolf Ent <<a href="mailto:ent@jlab.org">ent@jlab.org</a>>; Ernst Sichtermann <<a href="mailto:epsichtermann@lbl.gov">epsichtermann@lbl.gov</a>>; Matthew Posik <<a href="mailto:posik@temple.edu">posik@temple.edu</a>>; Lajoie, John G [PHYSA] <<a href="mailto:lajoie@iastate.edu">lajoie@iastate.edu</a>>;
Silvia Dalla Torre <<a href="mailto:silvia.dallatorre@cern.ch">silvia.dallatorre@cern.ch</a>>; Aschenauer, Elke <<a href="mailto:elke@bnl.gov">elke@bnl.gov</a>><br>
<b>Subject:</b> [EXTERNAL] MPGD: The Path forward</span> <o:p></o:p></p>
<div>
<p class="MsoNormal"> <o:p></o:p></p>
</div>
</div>
<div>
<div>
<p class="xmsonormal"><span lang="EN-US">Dear All,<o:p></o:p></span></p>
<p class="xmsonormal"><span lang="EN-US">As we discussed last Thursday we would like to meet again on Thursday 11:00 am 28th of September (assuming there is no tracking WG meeting scheduled at that time). To begin with, we would like to thank the presenters
at last Monday’s TIC meeting for the progress they have already made folding in the discussion from last Thursday’s meeting.
<o:p></o:p></span></p>
<p class="xmsonormal"><span lang="EN-US"> <o:p></o:p></span></p>
<p class="xmsonormal"><span lang="EN-US">Based on the excellent information we have received so far, we would like to define a path forward as preparation for our next meeting. To that end we are circulating the following questions/discussion points. One base
assumption that we will make is that heavy gases, i.e. Xe and Kr are available at the time EIC is operating. Based on this assumption we would like to understand:
<o:p></o:p></span></p>
<p class="xmsonormal"><span lang="EN-US">1. What R&D needs still to be finalized to show that the Standard ėRWell (as discussed on slide 5 of Kondo’s TIC presentation, leftmost column) provides an option for an MPGD tracker for ePIC even if the hit resolution
is inadequate. We would also like to see a time estimate needed to complete this R&D.<o:p></o:p></span></p>
<p class="xmsonormal"><span lang="EN-US">2. What <u>additional</u> R&D is needed to make a thin-gap ėRWell (as discussed on slide 5 of Kondo’s TIC presentation, 2nd column from the left) an option for an MPGD tracker for ePIC. We want also would like to see
a time estimate needed to complete the R&D for a full-size thin-gap ėRWell prototype. Again, we note that this should assume the availability of heavy noble gases and the gas should be chose to optimize the stability of the detector.
<o:p></o:p></span></p>
<p class="xmsonormal"><span lang="EN-US"> <o:p></o:p></span></p>
<p class="xmsonormal"><span lang="EN-US">While the hybrid GEM/uRWell may have applications in future detectors, the additional R&D required is inconsistent with the project timeline and introduces too much risk. The hybrid designs are not an option for ePIC.
<o:p></o:p></span></p>
<p class="xmsonormal"><span lang="EN-US"> <o:p></o:p></span></p>
<p class="xmsonormal"><span lang="EN-US">In parallel to developing the requested information about remaining R&D, Matt Posik’s simulation studies should be pursued because they will guide how small the ėRWell gap needs to be, i.e., maybe can one live with a
drift gap of 2mm instead of 1mm. It will be important to make the two methods of determining the angular resolution at the hpDIRC converge in the simulation studies so we can have some confidence in the results. The Astropix hits should also be included in
these simulation studies, and any remaining issues in defining the MC “truth” hit position in the hpDIRC resolved.
<o:p></o:p></span></p>
<p class="xmsonormal"><span lang="EN-US">With this parallel approach we believe the discussion boils down to a single parameter – the size of the drift gap in the ėRWell. The simulation studies will set this by determining the required spatial resolution,
and an understanding of the remaining R&D and how that depends on the size of the drift gap will inform the plan to develop the outer MPGD for ePIC.
<o:p></o:p></span></p>
<p class="xmsonormal"><span lang="EN-US">Thanks, <o:p></o:p></span></p>
<p class="xmsonormal"><span lang="EN-US">John, Silvia, Rolf and Elke<o:p></o:p></span></p>
<p class="xmsonormal"><span lang="EN-US"> <o:p></o:p></span></p>
<div>
<div>
<p class="xmsonormal"><span lang="EN-US" style="font-size:12.0pt;color:black"> </span><span lang="EN-US"><o:p></o:p></span></p>
</div>
</div>
</div>
</div>
</div>
</body>
</html>