Meeting notes Wed May 07

[Elton Smith <elton@jlab.org>]

Meeting notes Wed May 07
------------------------
Present: Stan, Randy, Elton, Elliott, Howard, Mehmet, Ravi and Dan Carman 
on the phone.


Setting up test station for FDC:
-------------------------------
- Dan has been in contact with Keith Solberg (IUCF) which has matched 
chambers that we might be able to obtain on long-term loan.
- They have 2 cosmic-ray test stands currently in use.
- Have 8-10 matched chambers, some 40x25cm2 (single layer) with preamps 
(originally PCOS II readout). Some may be available. (Some of these may 
date back to Dan's thesis with 200-250 um resolution).
- Larger 10ftx10ft chambers on long-term loan from Fermilab with multiple 
layers and electronics (resolution unknown)

Need: 
- scintillators for triggering
- support structure to hold chambers
- readout electronics

- Dan is getting more information on the chamber properties and 
availability.
- Elton will investigate how much electronics is available to support the 
entire test stand.

FDC prototype chamber needs 80 channels. Number of channels needed to 
instrument IUCF chambers presently unknown.

Other Charmbers
---------------
- Fermilab is giving Howard a number of single-wire chambers (8"x18") with
charge division readout in on dimension and drift time in the other. These
were built by John Krider. It is unclear what state they are in, but may 
come in handy, especially since they require very little readout 
electronics.

Status of FDC prototype 
-----------------------
- Randy presented the latest drawings on the prototype. The following
issues need updating and/or changing:

1. Strip space for glue
2. Fiducial markers 
3. Alignment pins (2) 
4. Check (with Fernando) that back side of cathode layer can be grounded.  
If so, we can eliminate 2 spacer boards)
5. Increase size of remaining spacer boards to allow space for glue 
(instead of adding shelf)
6. Add resistors to ground on circuit boards (10k Ohm?)
7. During discussions it was suggested to modify the kapton cathode boards 
to textend traces to preamps (instead of traces on thicker circuit 
boards). Randy will review and implement if he sees no difficulties

Randy will complete electronics drawings by Friday. These "final" drawings 
will be circulated for comments. We can then send them out after they have 
been checked.

On are related note, Dan mentioned that Steve Christo has an optical 
system mounted on a milling machine with cross hairs which can be used to 
check the location of wires during/after fabrication. Brian Kross has used 
the system recently and can help with setup.


-- 
Elton Smith
Jefferson Lab
elton@jlab.org
(757) 269-7625