TDIS Bi-monthly meeting, 2019 November 19

From Hall A Wiki
Revision as of 13:21, 19 November 2019 by Efuchey (Talk | contribs)

Jump to: navigation, search

Back to Tagged DIS run group >> Bi-monthly TDIS meetings

previous meeting << >> following meeting


Noise reduction in streaming readout prototype from Faraday cage

Target cell rolled with using 12um kapton film doubled over to produce a 24 um wall thickness


Attendees: Paul, Carlos, Ed, Thia, Eric F. (on-site), Rachel, Arun, Dipangkar (online)

  • Ed's update: the Faraday cage, as implemented, is very effective at reducing the noise to a low value of about 3ADC (on 10ADC bits samples), consistent over all channels, and presumably close to the baseline noise.
    • Discussion: general discussion about the SBS GEMs noise: Old Pedestal noise measurements have shown a sigma of 20 ADC for the UVA GEM chambers. However: strips are 4 times longer for UVA GEMs than for the MSU GEM, which increases the capacitance of these. Plus, SBS GMEs use APV 25 which have 12 bits ADC samples, so this 20 ADC value would be the equivalent of 5ADC on a 10ADC sample. So presumably it is not that bad.
  • Dipangkar's update: double-layer kapton cell has been rolled and is ready to be tested for pressure at 80psi.

Discussion: how to measure the thickness of the wall? suggestions: cut a prototype in the long direction and measure the wall; check light absorption, kapton being translucent (probably better because non destrictive); No way right now to check if there are air bubbles between the layers, other than visual inspection. Significant defaults in the thickness will probably be evidenced with pressure test. If occuring, ballooning will very likely happen at the level of the wall defaults.

Organizational details

11:00 AM, JLab meeting room: TED 2561A
To join the Meeting:
To join via Room System:
Video Conferencing System: -or-
Meeting ID : 550335940
To join via phone :
  1. Dial:
    +1.408.740.7256 (United States)
    +1.888.240.2560 (US Toll Free)
    +1.408.317.9253 (Alternate number)
    (see all numbers -
  2. Enter Conference ID : 550335940