Star-fst-l mailing list

["Ye, Zhenyu" <yezhenyu AT uic.edu>]

Minutes from the meetings last week

1. Hybrid:
Waiting for Gerard’s sign-off on v2.3 hybrid layouts. Updates after the 
meeting: Gerard sent comments and signed off on 11/25-11/26. 

2. T-board and Inner signal cables:
Waiting for Gerard's comments on the modifications to the assembled v2.1 
T-board. This is needed for assembling TEST inner signal cable for prototype 
module testing.
PO for 1000 ft production signal cables placed by Mike/John. Updates after 
the meeting: expect delivery by the end of the year or 1st week of 2020

3. Module assembly at Fermilab:
The first module fixture plate, which was fabricated by UIC machine shop, was 
examined with CMM at Fermilab. There are up to 30 microns shifts in the 
location of some holes/slots but are not critical and can leave as is. 
Diameter for holes A-D need to be increased by 10-30 microns and will be done 
by UIC machine shop. Also instructed the machine shop to order materials and 
make the other pieces for module assembly fixture and tooling. Updates after 
the meeting: P.O.s for commercial components went to UIC Physics accounting 
office on 11/26/2019. 

4. Installation of Prototype Module into STAR in 2020
We discussed the benefit and work needed for installing a prototype (or two) 
into STAR in 2020. We think having one module into STAR in 2020 will allow 
for early integration of the FST DAQ, slow control, online/offline software 
into STAR, while the amount of work seems to be small. We thus will keep 
pushing for it. Flemming will ask John to check if the IST grey cables have 
enough length to reach near sTGC and FCS prototypes.

5. Mechanical structure - YI
The first version of document is released 
https://drupal.star.bnl.gov/STAR/system/files/Mechanical_Structure_for_FST_at_STAR_v1.pdf

Structures received on 11/4 from EASTON had ~450 microns bending from the two 
ends of the outer structure (the bending may be even larger in the middle), 
and ~80 microns for the inner structure. By using PEEK+%30 Glass Fiber 
instead of CF, the bending issue was reduced but not completely resolved with 
the parts received on 11/19. EASTON is going to make further changes by 
splitting the mold between inner and outer structures (previously they are 
combined), and inject from the center. Some further changes were discussed 
(like removing some areas or increasing the thickness) but have been put on 
hold until we see the results of the new parts on 12/7. It is suggested that 
we should identify each version of the parts with an unique version number 
for discussion and future reference. 

AIDC is working on gluing hybrids onto the mechanical structure. The glue 
will have a thickness of about 80-120 microns. The thermal conductivity is 
not good. In the previous round of thermal-stress simulation, glue layer was 
not included between the hybrid (made of Kapton) and mechanical structure. Yi 
will check how the thermal conductivity of the glue compares with that of 
Kapton to see if new simulation is needed. A setup will be used to compare 
simulation and measurements. 

Radiation hardness of the glues (both for structure itself and for hybrid) 
will be looked into and be tested at BNL with Co sources (Robert/Flemming). 

We postponed the discussion on module storage and transportation box design 
to 11/27.

> On Nov 19, 2019, at 7:30 AM, Ye, Zhenyu <yezhenyu AT uic.edu> wrote:
> 
> Because of some uncertainty about Yi’s availability during the regular 
> meeting time, we will have a dedicated meeting on Mechanical structure at 
> 3:30-5:30pm BNL time on Thursday 11/21.
> 
> Zhenyu
> 
>> On Nov 18, 2019, at 4:22 PM, Ye, Zhenyu <yezhenyu AT uic.edu> wrote:
>> 
>> Dear all, 
>> 
>> We will have a weekly FST meeting this Thursday 9:30am BNL time. The 
>> meeting agenda and bluejeans info can be found at 
>> https://drupal.star.bnl.gov/STAR/blog/yezhenyu/forward-silicon-tracker-weekly-meeting
>> 
>> 1. Hybrid, T-board, Inner Signal Cable - Jianing, Gerard, Mike
>> 2. Mechanical structure - Yi, Han-Sheng 
>> 3. Module Assembly at Fermilab - Zhenyu
>> 
>> If there is anything else to report/discuss, please let me know. 
>> 
>> Best
>> Zhenyu
> 
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