Star-fst-l mailing list

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

Hi all, 

We have encountered a few issues with cables (both inner purple and outer 
grey cables) lately during the module production tests. Xu will give a 
detailed report on Monday.

As a reminder, for the production purple cables/T-board assemblies, SDU has 
mounted components on 10 T-boards, 2 of them are at NCKU for hybrid fit 
testing, while the other 8 have been assembled with purple cables by the 
company Mike works with (I will refer them as pre-productioin purple cables 
below). SDU still has 40 more bare T-boards waiting for testing results 
before mounting components and sent to BNL for purple cable assembly. So in 
total I expect that we will have 50 production purple cable/T-board 
assemblies, which I thought were sufficient for use in the experiment (36) 
and as spares. 

What worries me is the fraction of working purple cables seems to be rather 
low in prototyping and in pre-production. For example, out of the 8 
pre-production purple cables, we have tried four at UIC/Fermilab, and two of 
them have a problem (similar rate for prototyping). I think we really need to 
do QC/QA for the purple cable assembly, which I understand Mike has a QA plan 
but has not been executed. With this fraction of good quality cables, I am 
also worried that the number of good purple cable/T-board assemblies we end 
up having is insufficient, and I am wondering if we should have more of them 
produced. 

The problem with the grey cable that Xu mentioned is so far an isolated case, 
but we need to check the other grey cables we have to make sure the ones we 
use in the experiment do not have a problem. Mike, can you please remind me 
how many grey cables we have? (I think we really should make an inventory of 
all the electronic components, including the existing ARC, ARM, PPB, ABC, 
grey cables, purple/T-board, how many we have, where they are and their 
status) 

Best,
Zhenyu