Minutes-11-14-2013
November 14, 2013 FDC meeting
Contents
Agenda
- Installation status[1]
- Engineering (Bill)
- FDC survey
- Cooling system
- Electronics (Chris, Nick)
- Mini-DAQ for FDC tests [2] (Beni)
- Full electronics test analyses FDC E-log Entry 122 (Lubomir)
- Other
Minutes
Participants: Eugene, Bill, Dave, Nick, Chris, Simon, Vlad, Beni, and Lubomir.
Installation
- FDC was moved to the floor on Monday. Bill, Casey, and Dave glued the 16 reflectors to the gussets of the packages (four per package). The survey group started working on the new targets yesterday and they are working now. Preliminary findings: if looking along z they found distance between the first and last package to the be the same as the measured one within 0.5mm (measured with measuring tape?). However, they found that this is no longer the case if you look at some angle (w.r.t. the normal of the reflectors), as Eugene expected. They are now trying to find what is the angle range that is acceptable. They were also instructed to redo all the surveys they did before: the four SMR holders on each package and the flatness measurements.
Engineering
- We discussed again the previous survey results. As stated at the last meeting, Bill found that the nominal thickness of the first package is very close to the measured value from the flatness data. However, when he looked at the other packages he found that 4 is OK, but 2 and 3 are not: ~0.5mm discrepancy. In addition there's a discrepancy for the position of the 4th package as measured with the four SMR holders between the Blue Crab and the first survey in the Hall. That's why they will redo all the measurements now.
- Bill: we have all the parts to connect the cooling system. Bill will check if the chilled water is ready, and what else remains to be done. We discussed if we want to do the cooling system checks down on the floor, or up on the platform. Most of the people preferred to do this on the platform (the disadvantage: more difficult to check the manifolds, tubing at the bottom). Tom had an idea to have a long tube that connects the FDC on the platform to the chiller through the magnet which will be the final connection, but Bill prefers to place the chiller at the upstream side with a short tube to the FDC as a temporary connection.
Electronics
- Nick: all the cables have been nicely stored and organized in the cave behind the platform. The LV system is now connected. The two crates (fADC125 and F1TDC) that will be used for testing were mounted on the rack. The main issue now is the power for the crates. It turned out there's no 208V two phases on the transformer, that is the required power for the crates. In principle we can use 110V (but powering only some of the modules!), but it turned out there's only 15A and the crate requires 20A. Tom is looking now for a solution.
Mini-DAQ
- Beni has prepared a mini-DAQ system to test the cable connections while cabling. The system is now on "wilma" computer and has been tested there. See the link above for the full description of the system, as prepared by Beni. The system reads one module fADC125 and plots the pedestals; the widths will indicate proper connections. For the F1TDC the system sends pulses to the front of the pre-amp and gets back the timings. It's not a problem to install run the system from the new computer that will be on the platform "joebesser". As for the LV and HV system, Hovanes will be working on them; the systems are supposed to be ready but have not been tested with the real modules. In any case we can use Beni's LV system at the beginning to test the LV connections.
Full electronics test analyses
- Lubomir estimated of the wire resolution (see Entry 122 in the Elog linked above) using external tracking (IU chambers). Previous attempt to do this with package #3 (partial electronics) failed. Lubomir and Beni fixed a bug in the IU chamber configuration and the position resolution was improved from ~6mm to ~2.7mm. We use two cells with parallel wires, #1 and #4, take the difference between the track angles reconstructed from IU chambers on a 154cm base and the two cells, then multiply it by the distance between the cells (6.45 cm). This is a measure of the resolution of the two cells. The first plot shows the resolution of one cell (~200 microns in 1-4 mm distance-to-the-wire region), but it has to be corrected by the IU chamber contribution estimated to be ~110 microns (with big uncertainty!).
