iTPC

an Upgrade to Inner Sectors of STAR Time Projection Chamber


proposal draft (with link to bookpage)

SDU iTPC blog (Qinghu Xu)

Chinese iTPC project (part of Project 973 for RHIC physics)

STAR TPC

STAR TPC 2003 NIMA paper

mailing list: (itpc-l@lists.bnl.gov)

September 2016 NP iTPC review

September 2017 DOE Progress Review

  A talk on the iTPC was given to the instrumentation group on December 03 by FV. The talks is attached to this page.

 

 

 

An upgrade to Inner Sectors of Time Projection Chamber

The iTPC was developed into a proposal. The technical design report is available as a STAR note SN0644.

Historical remarks:

We propose to upgrade the inner sectors of the STAR TPC to increase the segmentation on the inner pad plane and to renew the inner sector wires which are showing signs of aging. The upgrade will provide better momentum resolution, better dE/dx resolution, and most importantly it will provide improved acceptance at high rapidity to |eta|<1.7 compared to the current TPC configuration of |eta|<~1.0. In this proposal, we demonstrate that acceptance at high rapidity is a crucial part of STAR’s future as we contemplate forward physics topics such as p-A, e-A and the proposed phase II of the Beam Energy Scan program (BES II). Unlike the outer TPC sectors, the current inner TPC pad row geometry does not provide hermetic coverage at all radii. The inner pads are 11.5 mm tall yet the spacing between rows is variable but always greater than 5 cm, resulting in "missing rows". Approximately, only 20% of the path length of the charged particle traversing the TPC inner sector has been sampled by the electronics readout.

https://drupal.star.bnl.gov/STAR/event/2014/02/10/star-rd-2014-and-itpc-review  

internal review: 
https://drupal.star.bnl.gov/STAR/event/2015/02/05/itpc-internal-review 

Electronics

New Electronics

Mechanic design of strongback

optimize strongback for more electronics readout channels and for reducing materials.

Drawings from the original TPC design

prototype iTPC strongback machining at UT Austin:
machining strongback 10/15/2013

TPC insertion tool:

First complete prototype strongback

ALICE insertion tool:

ALICE TPC Sector insertion tool

Multiple Wire Proportional Chambers

Fabrication of wire chambers

Pad size vs anode wire distance to padplance  
STAR Note #0263

Design of a prototype mini-drift TPC at SDU:
https://drupal.star.bnl.gov/STAR/system/files/iTPCmtg_0912.pdf

tools for measuring wire tension:
https://drupal.star.bnl.gov/STAR/system/files/wire%20tension%20measurement_1.pdf

wire tension parameters:

https://drupal.star.bnl.gov/STAR/system/files/Mathcad%20-%20wire%20tension%20formula.pdf 

Wire Distortion calculations:  

https://drupal.star.bnl.gov/STAR/system/files/wire%20distortion.pdf

Wire Chamber Assembly Comb: 
http://rnc.lbl.gov/~jhthomas/public/iTPC/iTPCcombs.pdf

Physics motivations

Searching for the possible tri-critical point in the QCD phase diagram is one of the major scientific tasks in heavy-ion physics.

Elliptic flow of identified particles has been used to study the properties of the strongly interacting Quark-Gluon Plasma.

Directed flow (v1) excitation functions have been proposed as promising observables for uncovering evidence of crossing a first-order phase transition, based on hydrodynamic calculations.

In addition to the above highlights of physics impact of the iTPC upgrade, the upgrade improves the tracking efficiency at low momentum.

The upgrade also significantly enhances STAR’s physics capability at RHIC top energy. The improved dE/dx resolution allows better separation of charged kaons and protons at high momentum.

BES II

Project Schedule, Cost and Management

This page have been repurposed to be the main page for management for the iTPC that was approved as a BNL Capital 
project (< 5M%$). The subpages will contain the main point for iTPC manegement. The old pages have been deleted at this point.

Cost and Schedule

Following the DOE review the project files are being updated.

November 20, 2016
Draft milestone table from current WBS  excel file 
The greyed out lines are poposed not to be in the Project Management Plan

Older files:
Management Forms from BNL; Project and cost files
The cost spreadsheet is from March 21, 2016. The numbers are used in the project management plan

Management plan and other documents

Project Management Plan: 
Version 12: updated version for September review.
Verdion 20: updated with KPP and clarification- changes since December marker in red.
Version 21: updated org chart  (Feb 2018)

Reports

 Reports quarterly.


Reports

 Reports quarterly.


ES&H reviews

 The material here is from several ES&H reviews and their follow ups.

compiled by Robert Pak 8/15/17

Attached is a folder of documents regarding safety reviews with C-AD you requested for distribution to DOE.  There were the following meetings (additional internal meetings and discussions with vendors occurred that are not included here):
i) ASSRC meeting on March 8th (Robert presented for Rahul).
ii) Engineering review of the installation platform on March 29th (Rahul presented remotely).
iii) ESRC meeting on May 8th (Flemming and Tonko presented).
iv) ASSRC meeting for enclosure with fire safety engineer on August 4th (Robert presented).
v) Installation platform inspection by C-AD on August 15th (no formal presentation).

Upcoming meetings include:
i) Meeting on tests in the clean area.
ii) ESRC meeting once power requirements for the new detector are finalized.
iii) ESRC walk through before turn on.

October 2018 DOE NP review

 Review was held at BNL

Here are the final reports

September 2016 iTPC NP review

The review was held on September 13 & 14 in Washington DC
All the talks and background material is available at the BNL indico page 

The closeout report will be posted once finalized.
I already extracted the recommendation and the comments that needs some action. Note it is preliminary since we do
not have the final report, but it should still beuseful. See attachment. (9/20/16)

The final close-out report was received on 12/14/2016 nd attached to this page. See list below

  • cover letter
  • excert from reviewers (personal comments)
  • final report

The talks from the Jan 2016 Directors review are on the BNL indico page

Response to recommendations

  1. Update on KPP -- we asked for more time on this which was granted
    We are suggesting a path forward for adding a KPP that reflects that the UPP dE/dx is achievable. At the review it was suggested, for example, to use the width from using signal from an 55Fe source. 


    The connection between observed resolution of an 55Fe source and final dE/dx is not trivial. The resolution of the source does e.g. depend on how the signal is read out e.g. via the pads or the wires. 

    We are pursuing this by simulations of MWPC response to 5.9 KeV electrons, by reviewing historical records since part of the original acceptance criteria was a scan of all sectors with sources, and investigating the just started tests with 55Fe source and X-ray gun at SDU, all to understand what the ideal response to stand alone measurements would be.

    We hope you will agree to such a path forward and the plan is to aim for having a quantified proposal by January 30 2017 for this KPP. Enclosed are the suggested table, and text.  

  2. Workforce for installation etc  main document
    1. workforce spreadsheet
  3. Lessons learned from previousconstruction
    1. Document (word) the double click does not work on mac OS
  4. Updated Project Management Plan with new milestones and resource loaded WBS
    1. The pdf of the updated WBS is here
    2. My comments to request and recommendation
  5. iTPC testing and commisioning plan September 2017

Background Material for Review

 The requested material will be collected here. For now it's the list that can be updated

  • TDR (November 2015)  SN0644 
  • Review report for Directors review (Jan 2016)
  • Response to review (Feb 15 2016)
  • Risk assesment Plan (November 2015)
  • Q&A Plan and procedures
  • Project Management Plan (pdf)

iTPC review responses

 The first response was by Oct 15 to provide an updated KPP. The repsonse that was send in is attached here

By November 1 we have to provide a workforce plans

The iTPC group should work with RHIC management to anticipate and identify workforce needs for construction, installation, and commissioning and develop a plan to mitigate any schedule risk due to a lack of technical and mechanical support personnel.  Submit the workforce plan to DOE by November 1, 2016.

I have worked with a few members of iTPC and STSG to come up with the first estimates. These are contained in two documanents
one describing the activities, and a second with a summary of resources. Its not yet complete.
See the attached documents.

The second items is

 Generate a Lessons Learned document from the construction and commissioning of the original STAR TPC and submit to DOE by November 1, 2016.

This has been discussed  and Jim proposes to generated a document with the many-many presenteation that we have assembled, and write an introductionary 
document.  This may actually serve us well to assemble all this material in a coherent fashion.
Document was submitted on time

The testing plan was submitted to DOE in mid September 2017 ahead of the  yearly review.

September 2017 DOE NP yearly progress review

 Meeting will be a BNL in room 2-160.

The call for review is the content of an e-mail send to me by Cassie Dukes of the NP office.

The talks for the review is on the BNL indico pages.

The final report was received in December 2017, and is included here

iTC Risk assesment

Nov 30, 2015

A draft version of the risk assesment has been assembled and is available for
comments  draft  

This page will also have some of the background of the iTPC risk assesment.

  1. Letter from Berndt Mueller  (word file)
  2. Draft Charge from Zhangbu (pdf)
  3. Risk Analysis Plan - Draft template from the Late Ralph Brown (word)



Background material

iTPC Directors Review Jan 2016

January 2016 Presentations on BNL Indico site

 

This page will be used to keep track of note, documentation need for preparation of the review.

  1. Jim Thomas comments to the Schedule as on Dec 11. 
  2. Further comments from Jim, and action from Flemming (word file)
  3. Comments from Blair on cleanness, HV and water systems.
  4. The most recent pdf print of the project file is here
  5. Unfortunately I cannot attach the MS project file- drupal does not allow that

QA page and documents

 This page contains the sector assembly QA schedule

  1. Pdf version of project file
  2. Project file (cannot be uploaded to drupal!)
  3. Sector assembly (and QA steps from Qinghua word file

iTPC QA

 
This page and the child page will contain information on the QA of sectors, organized by sector number
SN1001 is the prototype  SN00xx the production ones.

7/19/18 Added the daily test activity summary file. The daily updates are written by Qian, an has all entries in the file with the most recent first.

Latest version  8/26/2018

Hanseul made a nice webpage that  shares all update on the iTPC testing. 

https://docs.google.com/spreadsheets/d/11mFkoX1Mu64uL4oYq-vshhRE0bZa8CAqgsL1sToJ354/edit?usp=sharing


The traveller that is used for pre installation checks is attached to the page.

Summary of sector status  9/20/2018. A summary of problem sectors that should be considered as spare,
and not installed. Powerpoint File.

10/15/2018 screenshot of testing status at BNL




The material in the child pages are copies of the LBNL google pages, and additional analysis results that may have ben performed.

The LBL assembly instructions including check points is attached
The work at LBNL is completed as per 5/16/2018 and last sectors send to SDU

6/6/2018 : A pdf version of the final filled out smartsheet is saved here

6/6/2018: Jim  and Howard have analyzed all the survey measurements. The spreadsheet that summarizes the results is attached here.

The Chinese travellers are updated to Quinghua's blog page

The travellers for testing at BNL are posted on    https://www.star.bnl.gov/protected/heavy/tc88qy/iTPC/sector/

Travellers from the pre-installation check saved under each SNXXXX folder.
ITPC status  10/15/2018 . All sectors at BNL checked





Note: 
The two failed sectors SN0027 and SN0020 had separated in wide corners. Look fo repairs at LBL.
SN0024 failed the very sensitive He-leak test at LBL vacuum was 10-4 above the limits. It can be shipped to SDU
and see if it passes the Ar sniffer test.
SN0028 had failed complete along long edge. May be difficult to repair should be set aside.

The article 31-36 are the additional strongbacks to be bonded. Padplanes on, sidemount done. Waiting for final machiung, CMM and cleaning.
It is believed that SN0012, SN0027 and SN0021 are repairable, planned to be done during feb-March until the strongbacks arrive from IMT


Washing procedure changes ; double check vacuum, refill with glyptal.

The padplane connectivity and checkout QA is in the summary attached, and provide a list of all pad planes (34) inspected and the summary from the
QA sheets used during inspection


Reports on various issue, found and resolved. This is work in progress

January 3, 2018
  Report on shipping temperature for SN 1001

December 15, 2017
  Report on 2 FEE slots in SN0025 blocked by epoxy    

February 2, 2018

 De-bonding of PCB to Al  (GG wire) SN0015    

March 21, 2018
 Report on pad plane drilling survey at LBL for last 7

March 4, 2018
 Report of shifted GG board on SN0012

April 3, 2018
Report of grounded pins on ABDB board on SN0008



Shipping of sectors

August 2018  SN0014,1715 and 10
The temperature from the USB file.
The box was opened on August 2.
The pdf of the graph is here.

September 18 SN0001, 17, 31
Temperature from sensor for shipment




Article 7 SN0020

 

Article 16 SN0012

 This sector had a serious oversight during bonding resulting in a grounding wire caught below the pad plane.
As the wire is 600 microns think there is no way the flatness and bonding with expoxy which is only ~100 microns can be good.
Project have rejected this sector.

Article 17 SN0019

 

Article 18 SN0025

 

Article 19 SN0015

 

Article 20 SN0014

 

Article 20 SN0014

 Docs from LBL assembly

Article 21 SN0010

 

Article 21 SN0010

 

Article 22 SN0017

 

SN0018 (Article 24)

 

SN0031 article 31

 SN0031

article 6 SN0026

 QA from SDU

SN0026_traveller_scan.pdf 


article 1 prototype SN1001

 QA files for article 1.

article 10 SN0028

 

article 11 SN0024

 

article 12 SN0029

 
This sector was found at SDU to have the right GG side mount out of spec, just at limit where the
wire would touch the side mount surface
The figure shows the measurements from SDU and LBL CMM for righthand GG sidemount
The difference is understood due to way measurements are done 30-50 microns 

A copy of the SDU traveler is at this location 

article 13 SN0030

 

article 14 SN0021

 

article 15 SN0011

 

article 2 SN0009

 QA infor from LBL and analysis

QA from SDU

Traveler 

 

LBL spreadsheets etc as attachments
 
 
 
 

article 3 SN0006

 
Traveller from SDU production link to Qinghua's blog

article 4 SN0022

 LBL survey info
SDU scanned production traveller (upkoad 10/8/2017)

article 5 SN0027

 
The sector was rejected due to separated plane 8/16/1017 -- returned to LBL

The QA travellers from SDU


article 8 SN0023

 QA from SDU

SN0023_traveller_scan.pdf 

Sn0023_test results.pdf

article 9 SN0016

 QA from SDU

SN0016_Traveller_scanned.pdf


  1. Right side of anode wire mount apart from strongback about 5cm -- repaired at SDU
  2. two tapered pins extruded ~2mm beyond the side wire mount
  3. 5 pins of LOAB missing/broken repaired at SDU
  4. leakage found on 8 feed-through boards - re-epoxied
  5. Two fat wires used  75um BeCu wire used instead of 125 by mistake no effect from simulation by Irakli

iTPC Quarterly Reports

In this page I will also keep the slides for the monthly phone conferences with DOE, as well as brief minutes

 It is organized according to WBS. The lead people for each section is given here.

  • Project Management  --  Flemming
  • Padplane -- Flemming 
  • Mechanics-Strongback -- Flemmig
  • Mechanics -MWPC -- Qinghua
  • Integrations & installation R-- Robert
  • Electronics -- Tonko
  • Software - Irakli
  • Other activities -- Flemming

Flemming is responsible for the reports as such.

In general the report should be completed by mid-July, mid-October ,etc...


Quarterly reports

Monthly phone conferences

iTPC brief reports and presentations

 Page to keep track of various brief notes, documents for iTPC

2017

May 24, 2017   Gain measurements on prototype MWPC at SDU - pdf
May 18, 2017   Notes on assembly issues for article 2, 3 side mounts - word document
April 28, 2017  Notes on broken pins - article 2  word document

Aug 22, 2017 Brif update on status at SDU (FV) presentation


iTPC closeout review May 2, 2019

Final report and experts from the review were received on August 1, 2019
The three documents have been attached 
cover letter
Review report  
Excerpts from reviewers

---

The material for the closeout review including talks are all on
https://indico.bnl.gov/event/5980/

On this page I added the 3 final documents: close-out report, lessons learned, and the transitions to ops.
 --
 The close out review for STAR has been scheduled for May 2. The notice from DOE is enclosed here
This page will be used for the preliminary material, Final talks and material will be put on a BNL indico page
as we did for the previous reviews.

As the iTPC project is neither an MIE no a project for the CD process, I believe the requested closeout and transition to ops documents
can be fairly brief.

-- notes from DOE NP

As you know, the dates for the STAR iTPC Project Closeout/Transition to Operations Review has been confirmed for May 2, 2019. Attached, please find a list of the reviewer panel and anticipated DOE participants. For your information, the web-conference info is included below for distribution to the panel via the review website.

 

Join from PC, Mac, Linux, iOS or Android: https://science.zoom.us/j/737668005

 

And/or join by phone:

 

    +1 646 876 9923 (US Toll) or +1 669 900 6833 (US Toll)

    Meeting ID: 737 668 005

 

Note: with the ZOOM web-conference, if the equipment you are using is not equipped with a microphone, you will need to use the link to log into the meeting to share/view presentations, as well as call-in via phone for voice participation.

 

Please draft an agenda and a list of proposed documents to be sent to the review panel prior to the review  (for example, previous review report, response to DOE Review Recommendations, etc.). Please note: background documents should also include a draft Project Closeout Report, draft Transition to Operations Report, as well as a draft lessons learned document.  Once the draft agenda and the list of proposed documents have been prepared please send this input to me for comments – I will collect comments from all applicable individuals within the NP office and will iterate with you on the agendas to ensure all topics are covered. Once the materials have been finalized, please make the background materials, as well as presentations, available to review participants in electronic form as soon as possible but no later than two weeks prior to the review (presentations can be made available at a later date, however, we request no later than 5 days prior to the review).

The panel members are in the attached document

-- as previous e-mail the charge for review content is

Please hold May 2, 2019 for the Project Closeout/Transition to Operations Review of the STAR iTPC. We are happy to schedule the meeting as early as possible, however, this is likely to be one-day starting no earlier than 9:00 am ET with an executive session, 9:30 am ET for presentations to start. For your information, suggested topics for talks and the schedule for the one day close out meeting would be as follows:

 

-              Project status and deliverables

-              Project commissioning results 

-              Cost and Schedule

-              Management and Safety issues

-              Transition to operations

-              Working lunch and executive session to write a few page report

-              Close out   (early afternoon, between 2-3 pm)

--
I should point out all t6he charge bullets is what any project from 5M$ and up is subject to.

iTPC meetings

A child page maintains a list of all tpc meetings and the technical meetings held
for integration , installation. Some presentation are listed on that page

The meeting summary up to October 2015  
was kept in Quingha's blog page here


For meeting related to safety see https://drupal.star.bnl.gov/STAR/subsys/upgr/itpc/esh-reviews

Electronics Production Readiness Review

 An iTPC production readiness review was held on January 22, 2018

The agenda was:
the review will take place tomorrow at 1 pm EDT at 1-224 in the physics department.
Agenda:
Introduction 10 min  F.Videbaek
Electronics   40 minutes  Tonko Lubicic
Discussions; questions and answers 20 min
Commitee discussions 40 min

The committee will write a report to be send following the meeting to the iTPC group.
Report was received on January 23, 2018

iTPC minutes

 The following regular meetings are being organized for the project
  • Weekly iTPC meeting for all interested. Wednesday's at 10.30 am;  9.30 when standard time
    • The agenda is usually mgt updates, report on electronics, SDU, mechnics
    • The integration , installation is usually discussed primarely at the Monday meetings
  • Meeting info updated onMay 15; We are havig continuous problems with eZuse and go to BlueJeans
  • Phone Dial-in
    +1.408.740.7256 (United States)
    +1.888.240.2560 (US Toll Free)
    +1.408.317.9253 (Alternate number)
    (Global Numbers)

    Meeting ID: 832 810 289
    Moderator Passcode: 6253 

    Room System
    199.48.152.152 or bjn.vc

    Meeting ID: 263 878 370
    Moderator Passcode: 6253
    Description:
    weekly iTPC for status updates
     
     




  • The mechanical meeting series is complete with the final installation of all sectors on October 2018
  • Bi (or weekly)  weekly meetings of internal iTPC working group to define, and follow up on mechanics, and installation. Currently on Mondays at 1.00 pm.Meet in 1006 using the STAR ops standing eZuce reservation. Minutes attached (latest update 7/7/2016) from earlier meeting. The individual meetings will show up in list below here from. Meeting is led by Robert Pak, with engineers, techs,  physicist and from BNL and LBL, and minutes written by him.
    • August 30, 2018 minutes
    • April 19, 2018 minutes
    • April 12, 2018 minutes
    • March 15, 2018 minutes
    • March 8, 2018 minutes
    • February 22, 2018 minutes
    • February 12, 2018 minutes
    • December 18,2017  minutes
    • December 11, 2017  minutes
    • December   6, 2017 minutes
    • November 20, 2017 minutes
    • November 13, 2017 minutes
    • November 6, 2017 minutes
    • October 30, 2017 minutes
    • October 23, 2017 minutes
    • September 25, 2017 minutes 
    • September 11, 2017 minutes
    • August 28, 2017 minutes
    • August 21, 2017 minutes
    • August 14, 2017 minutes
    • August 7, 2017 minutes
    • July 31, 2017 minutes 
    • July 24, 2017 minutes (installation plan, clean room, spreader bar)
    • July 17, 2017, minutes (insertion tool, platform, clean enclosure, clean room)
    • July 10, 2017, minutes (Clean enclosure, AOB)
    • June 26, 2017 minutes
    • June 19, 2017 minutes
    • June 5, 2017 minutes
    • May 22, 2017 minutes
    • May  8, 2017 minutes
    • April 24, 2017 minutes
    • April 10, 2017 minutes
    • March 27, 2017 minutes (sideboards,LBNL activity, Mark update, Rahul installation)
    • March 13, 2017 meeting (LBL progress, items to ship,  testchambers)
    • February 27, 2017 meeting (QA pad planes,anode wire mounts, Update from Mark,Canary Chamber, Shipping containers)
    • February 13, 2017 meeting 
    • January 23, 2017 meeting (QA padplanes, wiremount cleaning, update LBNL)
    • Janunary 9, 2017 meeting (QA padplanes, wiremount cleaning, tooling LBNL, canary tests)
    • December 12, 2016 meeting (padplanes sidemounts canary tests insertion tooling)
    • November 28, 2016 meeting
    • November 14, 2016 meeting
    • October 31, 2016 meeting
    • October 17, 2016 meeting
    • October 3, 2016 meeting (padplane, combs, wiremounts, inventory, shipping containers canary chamber, installation platform kickoff)
    • September 19, 2016 meeting
    • August 29, 2016 meeting (padplane, report central shop, insertion tooling)
    • August 1, 2016 meeting (strongback inspection, combs, assembly inventory)
    • July 18, 2016 meeting    (strongback production, wire mounts, wire combs, insertion tooling)
    • July  5, 2016   meeting  (strongback QA, canary chamber, insertion tool, padplane)

iTPC run18 progress

 The page will contain material presented at the itpc software meetings,
or circulated with the group. Material will be in reverse order
The meeting will be on Mo and Th 11 in general.
The bluejeans information is

Phone Dial-in
+1.408.740.7256 (United States)
+1.888.240.2560 (US Toll Free)
+1.408.317.9253 (Alternate number)
(Global Numbers)

Meeting ID: 634 285 245
Moderator Passcode: 6253 

Room System
199.48.152.152 or bjn.vc

Meeting ID: 634 285 245

April 23, 2018 A few pictures comparing iTPC and TPC by Yuri

April 18, 2018 Update on Gain on iTPC  (Tonko)

April 16, 2018 Further analysis of clusters and distribution (Flemming)
File on Monday meeting https://drupal.star.bnl.gov/STAR/event/2018/04/16/itpc-software-monday

March 29, 2018
Analysis of 86040  . Charge distribution plots

Entry April 2, 2018/ update by 4/8/18

Adc vs pad for different rows (FV)

Yuri' update after gating grid leak fix 

Entry March 29,2018 

Charge distribution per row for inner sector The profile has been fitted with a landau distribution

Similar plot for the outer sector

March 2018  Tonko analysis of iTPC pulser run

iTPC NIM paper page

  This page is meant to have reference links, suggested plots, tables etc.

- From Zhangbu

Last week, Robert brought to my attention that iTPC is one of the greatest accomplishments STAR did in the last decade, and 
now that the BESII data have been taken, and analyses are on-going, 
we should write a NIMA paper to document:  
mechanic structure and pad/electronic layouts,  

Operation and performance, 

Online/offline Calibration and Physics technical performance

 

It is also important to document this for future physics paper references and also 
serve as a historic document before everyone moves on and forgets about all the details.

From Robert -
outline based on DNP talk  NIM_outline

Reference documents
The technical design report is available as a STAR note SN0644.

The iTPC closeout report with KPP and performance plots

The Shandong group wrote two NIM performance papers
1)   F. Shen et al., MWPC prototyping and performance test for the STAR inner TPC upgrade, Nucl. Instrum. Meth. A 896, 90 (2018).

2) X. Wang et al., Design and implementation of wire tension measurement system for MWPCs used in the STAR iTPC upgrade, Nucl. Instrum. Meth. A 859 (2017) 90–94.