Star-tpc-l mailing list

[videbaek <videbaek AT bnl.gov>]

Hi All

I was a little baffled that the issue of voltage scan was brought up 
today without
discussing details with the group as such. We did discuss this a few 
weeks ago and agreed it was a good idea.
I understand time is running out (1 week left).

To get some discussion some questions:
- how many track are needed per sector
- what is the voltage range  - we did some measurements when iTPC was 
installed, and lowering out outer TPC
(2019 or 2018?)
-
Some comments
- The MB rate i 3.8k in the low lumi config
- This scan should be done within the 2 hours that a typical low lumi 
period is.
- The overhead between runs i.e start/stop + changing voltages is 
probably 4-5 minutes, particular
  if some individual channels are to be set. Why not go down in voltage 
steps from current operating.
- What is the need for going up? We risk trips this should be avoided.
- I made a rough estimate of tracks per sector per minute  and get 
~0.5-1.2 M tracks/mi
n/sector, Probably a low estimate, but efficiency goes down as voltage 
is lowered.

best Flemming








--
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