Revision as of 13:33, 12 June 2010

Location, Time

Friday, June 11, 2010
2:00 pm EDT
JLab: CEBAF Center, Room F326/7
ESNet: 8542553
EVO: direct meeting link (good through 8/20)
Conference Group: 800-377-8846, participant code: 77438230
Slides: talks can be deposited in the directory /group/halld/www/halldweb1/html/talks/2010-06 on the JLab CUE (you have to be a member of the "halld" group). This directory is accessible from the web at https://halldweb1.jlab.org/talks/2010-06/ .

Agenda

1. Announcements
2. Minutes from the last meeting
3. Time-of-Flight
   1. Prototype progress
   2. Status of the MOU
4. Start Counter
   1. prototype progress
      • attenuation length measurements
5. Target
   1. Status of the MOU
   2. Status of refrigerator plan
6. Action Items

Minutes

FSU: Paul Eugenio, Sasha Ostrovidov Jlab: Tom Carstens, Eugene Chudakov, Mark Ito (chair), Chris Keith, Sascha Somov, Simon Taylor, Tim Whitlatch, Beni Zihlmann

Review of minutes from the last meeting

We went over the minutes].

PMT purchase for TOF prototypes

Paul sent the quote, Mark submitted the purchase requisition, and now the purchase order is all set to go out, we just need a shipping address at FSU to attach to the PO.

Refrigerator for the target

We started from the entry in the minutes about the lab-wide review of helium demand.

• Chris commented that if we do get a pulse tube refrigerator for cryotargets, that it actually might be able to service a frozen spin target. We did note, again, that such a target is not part of any current plan for Hall D.
• Tim is in the middle of a cryogenic requirements review for the Hall and a decision on purchase of the recommended refrigerator is pending on completion of his work.

Time-of-Flight

We spent a lot of time updating issues reported at last the last meeting.

pulser cannot easily be changes in amplitude athens scheme talk to elton about calibration system in hall b right now working on testing system at fsu nichia led stability of pmts is an issue time walk done once per year not necessary to do continuously g12 used laser to calibrate tof 1/3 of channel the time walk with the laser data from run in 2001, worked well, time variation in correction very slow dr carman still doing it: tom potentially lser for hall a kevin gio for calorimeter, nitrogen laser

change of thickness of counters • pmt has min cathode diameter of 46 mm • cutting ert to 46 mm diameter, • cookie on one end of bar • light reflect out to see if any coming in outside that diameter • current plan: silicon cookies, silicon sheets from eljen[sp?] • initial glued pmt • tim has done lay-outs • rtv glue possibility, eugene

wrapping • large sample of esr df2000 ma • studies about to start • final light tighe overwrapping, still wait

changing the dac

• received ti board • will be running with led • use a real triggered system • to match adc's and tdc's • vme64 bridge, not using coda • working on program to control

changing trigger paddles to use longer counters to improve rate

MOU

• DOE grant has off campus overhead rate • discussion with chair on MOU. waiting to hear back on overhead rate, • argue that saving money to doe by paying a lower rate

two full length some beam hole length to be machined