OWG meeting 22-Aug-2008

Agenda

• Announcements
• Review of minutes from 8-Aug-2008 meeting
• New meeting time - all
• FADC125 report - Gerard
• DAQ test stand status - Elliott
• PMT test status and results - Beni, Werner short report
• Update on fiber test stand - Beni
• Controls organization - Jim, Elliott [1]
• Electronics update - Fernando, Ben, Ed, etc.
• Party for Christoph 3pm!

Time/Location

22-Aug-2008 1pm CC F326

To connect by telephone:

I believe Gerard is the only one phoning in, so we will call him directly.

If this is not the case please let me know and I'll set up a conference call. You can then use the following instructions:

1.) dial:

• 800-377-8846 : US
• 888-276-7715 : Canada
• 302-709-8424 : International

2.) enter participant code: 39527048# (remember the "#")

Next Meeting

NOTE new time:

5-Sep-2008 2pm CC F326

Minutes

Attendees: Simon T, Herun Y, Elton S, Carl T, Beni Z, Alex S, Jim S, Fernando B, David L, Mark I, Ed J, Elke A, Gerard V by phone.

Meeting Time

Starting 5-Sep-2008 we will meet at 2pm on Fri.

FADC 125

Gerard reported on the status of the 125 MHz FADC board. See his report above for more details.

• Testing using eval boards from manufacturers.
• Input from signal generator and from ASIC.
• Using one of two channels on eval board.
• Response with 21m cable looks good.
• 28 nsec peaking time.
• Cable temperature has noticeable effect.
• Full width about 90 ns with 5 10**4 gain, t0=1.38 ns.
• Tail cancellation can be improved.
• Noise as expected, dominated by preamp instead of ADC, gain dependent.
• Good common mode noise rejection.
• All indications concerning the full board are good.
• Behind on full board delivery, but now expect to start fab by beginning of Oct.

DAQ Test Stands

Elliott reported on existing and future DAQ test stands. See link above for details.

• Hall D equipment loaned to many university groups.
• Some equipment at JLab in various test stands: FDC, fiber test stand, PMT test stand.
• Collecting equipment whenever possible (i.e. beg, borrow, steal).
• Have a number of computers now.
• Short on NIM modules.
• FCAL test is coming up.
• Much discussion on whether we need to buy a high-end portable scope soon.

PMT Test

Beni reported on Werner's testing of Hammamatsu fine-mesh PMT's in the Hall A BigBite magnet.

• One channel 1.5" HP6614 Hammamatsue fine-mesh PMT (1" tube died).
• Used LED pulser and fiber.
• Measured PMT response vs B field and angle.
• More noise than XP2020 below single electron peak.
• Works at 1.2 T but loss of gain by factor 100.
• Best gain around 40 degrees, no signal beyond 50 degrees.
• Didn't check azimuthal dependence.
• Werner is writing up results.

Fiber Test Stand

Beni reported on the status of the fiber test stand.

• Using XP2020, light source, fiber.
• Received Sr source and collimator.
• Seeing signals, some puzzles (reflections?).
• Still waiting for light box parts.

Controls

Jim presented his thoughts on how to organize controls documentation. See his report above for more details.

• A lot of info is needed for each controls channel.
• Jim began a spreadsheet capturing the info. Started with the sweep magnet power supply as an example.
• Cabling costs can be significant!
• Information eventually should reside in web-accessible database. Might be submitted to Online Group via spreadsheet and then entered into database.

Christophe's Retirement Party

We all left for the party just before 3pm.