<html><head></head><body>Hi all,<br><br>The minutes I jotted down for December's GEM monthly meeting that was held two days ago have been attached to the meeting agenda and copied below.<br><a href="https://hep.ustc.edu.cn/indico/conferenceDisplay.py?confId=9">https://hep.ustc.edu.cn/indico/conferenceDisplay.py?confId=9</a><br><br>MPGD R&D at Temple University (Bernd Surrow)<br>------------------------------------------------------------------<br>- Aims: low-mass large planar triple-GEM and cylindrical MicroMegas<br>- Resources including two labs and various setups in the labs for the R&D were shown (gas, HV, DAQ, CCD/F55 scans, leakage current monitoring, cosmic-ray test …)<br>- Status <br> + GEM<br> * GEM foil quality check procedure well established. <br> * small test chambers assembled and tested<br> * a big effort being made on low-mass design of large GEM involving non-stretching of GEM foils and use of carbon fiber for support structure<br> * single mask technique has been transferred from CERN to a US company for commercialisation of large GEM foil production.<br> + MicroMegas<br> * two flat MicroMegas chambers assembled and tested. <br> * first-version DREAM chips (low noise, suitable for large input capacitance) employed and tested <br>- Expect to order and test large MicroMegas and GEM foils next year<br><br>Design of APV25-based GEM readout system ( Cheng Li)<br>------------------------------------------------------------------------------<br>- designed a backplane to connect APV5 FEE<br>- Specifics of the main components (ADC, Clock, FPGA, interface …) of the system have been determined. The schematic design almost finalised.<br>- PCB design to start soon<br><br>Tests of a 30*30cm^2 GEM chamber (Wenhao You)<div>----------------------------------------------------------------------<br>- tested counting rate vs. working voltage, identified efficiency plateaus in sectors<br>- tested the gain of most of the sector by irradiating the chamber with X-ray and measuring the current drawn in each sector<br> + gas gain of 10^4 - 10^5 observed on the plateaus.<br> + gain uniformity over sectors looks not good. More work to be done for it. <br> + the remaining sectors to be tested<br><br>Preliminary results on non-uniformity effects and the status of large GEM chamber (Zhigang Xiao)<br>------------------------------------------------------------------------------------------------------------------------------------<br>- tested the impact of non-uniform space between GEM foils on GEM gain by introducing a spacer on one side of the GEM foils<br>+ two configurations tested which had different distance between the two GEM foils and different size of the spacer<br>+ GEM gain decreases with the increasing of distance between GEM foils as expected. Quantitative results available. <br>+ Energy resolutions showed some edge effects, and generally improved with the increasing of the distance between GEM foils, which was not fully understood yet.<br>- presented some GEM simulation results with Garfield (e.g. gain)<br>- large GEM chamber<br>+ readout PCB delivered<br>+ expect to assemble the large GEM chamber in the next two months in IMP<br><br><br>Progress in GEM foil R&D and test of APV25-based readout system (Siyu Jian)<br>----------------------------------------------------------------------------------------------------------<br>- test of readout <br> + made a backplane locally, testing the new system for better performance. <br> + assembled a test GEM chamber and preparing for testing the chamber with the readout system<br>- GEM foil R&D<br>+ breaking news: successfully reached the 3th step (before etching kapton foil) in the GEM foil production with double mask technique. Going further requires upgrading the present lab to handle poisonous condition led to by Kapton foil etching.<br>+ looking into integrating the Cu etching for GEM holes and that for GEM rim.<br>+ GEM lab upgrade to be finished before middle January (very great news, hopefully we will have GEM made in China in the not far future)<br><br>Lastly, happy new year to everyone and wish us a good 2014 ahead for GEM!<br><br>Jianbei<br></div></body></html>