A GEM Detector System for an Upgrade of the CMS Muon Endcaps

Two actions have been taken in 2011. The first one consisted in securing team competence by opening two strategic
LD positions in the MPGD domain (one technician for design and one technician for construction). The second one
is to initiate a program of MPGD industrialization, within the framework of the RD51 WG6 (production) working
group. A technology transfer program for GEM foil manufacturing has been established with NewFlex, a flex PCB
Production Company located in South Korea. They were able to produce the first GEM foils of 6cm×6cm, which
have been assembled in a detector and successfully qualified at CERN. NewFlex has recently performed a new
production of 20 samples of 10cm×10cm GEM foils, which will be tested at CERN in January 2012 to qualify the
production stability. If successful, the program foresees the manufacturing of larger size GEMs of 30cm×30cm
and later in 2012 of a real CMS size. Regarding the CMS needs for GEM detector in the high-η region, the TE-
MPE-EM workshop plans to make available its know-how and facilities for the development and supply of the
GEM detectors. The CMS planned quantities and deliveries are listed in the Table 4.
Table 4: Summary table which lists quantities and deliveries
Station Num of Module Total number of Total foil area Manufacturing
modules area modules w/ spares (Triple-GEMs) plan
1 18×2×2=72 ≈0.55m 2 (1037x526) 80 132m 2 Yrs 2013+2014
2 36×2×2=144 ≈1.6m 2 (1301x1251) 160 768m 2 Yrs 2015+1016
Station 1 could be produced at the CERN workshop at the production rate of about 12 GEM foils/month and 4
modules/month. The minimal needed manpower will consist of 2 field support units (FSU) people to be 100%
devoted to the CMS Moun upgrade project, one for the GEM foil manufacturing and one for the detector assembly
and test. One dedicated test stand has to be built. Additionally CMS shall make available a clean room of about
40m 2 for the assembly and test of the detectors. As the workshop is planned to move to the new building 107, it
may be possible that additional clean room facility could be shared for this production batch during 2014. Station 2
needs the contribution of industry for the mass production of GEM foils. It should be planned a minimal production
rate of 24 GEM foils/month and 8 modules/month. The workshop could take care for the detector assembly. Two
FSUs have to be 100% devoted to the assembly and test procedures. The test stations need to be duplicated
to sustain the production rate and to provide backup in case of repair of modules and in the event of test stand
breakdown.
In addition, industrial contact has been established and technology transfer of fabrication of GEM foils to a firm
“New Flex” in Korea has been completed. Twenty GEM foils produced in Korea have been delivered to CERN
and are in the process of validation test in a detector. At the foil level, the quality controll was passed and full-scale
foils are in the pipeline. Once the project is approved CMS baseline detector will be built by “New Flex”, Korea,
setting up redundancy in the production.
Details about the installation sequences, integration within CMS and its services can be found in the Appendix B.
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