Star-tpc-l mailing list

[videbaek <videbaek AT bnl.gov>]

TPC meeting 1/11/2024
Present: Jim,Yuri,Gene,Tommy, Flemming, Frank

Hardware:
The powerdip and subsequent power loss  several days ago is slowly being 
restored to the WAH.
There are severe issues with the Alan Bradley safety system that 
prevents it from being brought back. Alexei and jim are looking into 
this. Wayne has also been asked to bringe (seveal) computers back to 
lift. It looks like either the cpu, or the fiber optic boxes has issues 
(in gas room or on platform).

Data:
Gene had looked further into the field cage current discussed last week.
1)	The central membrane voltage change o day 157 from 27,995 V to 28,005 
V after the shutdown caused by smoke incident and shutdown due to HDSD 
system. This change persisted to the end of the run.
2)	Bimodal response in current , mainly inner, was seen during day 
175-180.
3)	Humidity caused issue (due to chilled water issues) for ~10M events 
on day 168. Considering marking these as bad- it is only ~1% of total 
data set.

Alignment
Yuri discussed results of survey of TPC to maget. Compared results from 
2004 with 2023 survey. General small difference of < 0.1 mrad possibly 
0.2 in alpha (rotation around x axis.
One puzzle comparing some distance measurements in x,y that were ~ 1mm 
from design drawings. See Yuri’s blog entry  from 1/10.

FXT issue
Discussion on special issues for FXT tracking.
-       Trigger gitter
-       Ways to possible improve tracking for heavier masses.
-       Yuri will pursue this further.

--
Flemming Videbaek
senior scientist, emeritus
videbaek @ bnl.gov
Brookhaven National Lab
Physics Department
Bldg 510D
Upton, NY 11973

phone: 631-344-4106
cell     :  631-681-1596