Fiber Tracker Meeting Minutes
September 23, 2003 - 10am, Farside
- CFT Electronics Status : Borcherding
- first week of shutdown, calorimeter was doing noise studies so we couldn't look at much
- by the end of the week, were able to look at modified boards and were surprised:
- some channels had pedestal means move up systematically due to the modification done
(8 places in a board)
- we had seen this effect at test stand at 5-10 counts, but on the platform it was much larger
- guess it took making modifications to a whole crate to really show the systematic effect
- also saw that the discriminator thresholds for SIFTs 1 and 4 needed to be higher;
before all four thresholds were about equal
- ran tests to better understand what was going on - developed a model that seems to describe
the behavior well, as later modifications produced expected results
- conclusion is that having resistors on the board is bad; solution seems to be to completely
remove both the resistors and the capacitors (installed earlier)
- as an extra benefit, removing the resistors and capacitors ends up allowing the unused
channels to be surpressed
- at the moment crates 4-7 have the added resistor; most of crate 8 and all of crates 9-11
have both res and cap removed; studies continue
- 3 options:
- back out of current modifications (run with capacitors on the boards)
- proceed w/ planned mods - not recommended by the techs who are concerned about lifetime issues
- remove both the resistors and the capacitors
- hope to make a decision by later today
- tasks not started:
- sequencer crate power supplies to be worked on - scheduled for a week from Monday
- AFE LV power supply work not started yet because parts not here yet
- L1 muon trigger work to be done by others - we need to have some of our crates running for this;
they think to do that next week
- we've been fingered as a possible source of noise for the calorimeter
- Fourier analysis of clock aquire signals shows a 10MHz line
- unfortunately all detector components produce this - SMT is biggest culprit
- Proposal to change this meeting's time : Alton
- Possible times suggested:
- Monday 1-3pm in the Farside
- Farside is available assuming that the operations meetings don't really happen any more
- competes with:
- online monitoring
- RunIIB L1 CTT
- Boston U. group
- Tuesday 9:30-11:30am in the Farside
- room is available
- competes with:
- Muon ID
- Stony Brook's STT
- Wednesday 10-12am in the Farside
- room is available
- competes with:
- common sample (A week) or top / b tagging (B week)
- online projects
- other possible Wednesday times:
- people present selected Monday 1-3
- Alan will send an email out with Monday as the proposed change and get comments
- Drew will check with Dmitri to confirm that the room will be available
- Mice Update : Bross
- fiber planes are being manufactured much faster than expected
- first one might be shipped to Fermilab next week