Oct 7, 2009 Readout
From GlueXWiki
Teleconference Time: 12:15 p.m. EST
- ESNET and EVO session
- Phone:
- +1-800-377-8846 : US
- +1-888-276-7715 : Canada
- +1-302-709-8424 : International
- then enter participant code: 77438230# (remember the "#"). Phone connection only upon request.
Contents
Items for followup from previous meeting
- Ship Baby Bcal to USM.
- Make progress on USM MOU document (Elton, Will, Eugene)
- Optimization of Bfield direction and magnitude relative to pmt
- Light collection efficiencies for light guides for "USM" geometry.
Documents to Review
- Media:Draw trigs 38deg.pdf Media:Draw trigs 73deg.pdf for segment #2.
- Entrance rectangle is 3.01x4.0 cm. Exit radius is 1.35 cm. Length of trapezoid/cone is 60 cm, and length of torus is also 60 cm.
- This configuration should be comparable to Alam's "cylindrical cone" geometry.
- See also Effective diameter vs B field and angle from Antonelli et al., NIMA 368 (1996) 628-634.
- Magnetic field plots
Tentative Agenda
- Announcements
- Review of Action Items
- Plan for SiPM Testing (Carl and Fernando)
- USM report
- Light Guide Geometry
- Light Guide Simulations
- Discussions on MOU with USM
Minutes
- Attending: Elton, John, Fernando, Carl, Tim, Sasha, Beni (Jlab); Eduardo, Sergey, Will, Alam (USM); Zisis, George, Andrei (Regina).
- Announcements
- Review of Action Items
- Progress on all issues except for shipping of baby cal to USM. Alam is in conversation with university administration and hopes to resolve the issue in a couple of weeks.
- Plan for SiPM Testing (Carl and Fernando)
- Five SiPM units from Hamamatsu arrived this morning. Will be picked up by Carl. Expect remaining five units to be shipped next week.
- Fernando: Electronic assemblies are almost complete. Will begin testing electronics for Hamamatsu units on Monday.
- Carl confirmed the tentative test plan for the SiPMs. Will begin by checking individual cells in the array. Then run a linearity curve, leaving some units exposed to high light levels for a period, before checking their quiescent state.
- USM report
- Light Guide Geometry
- Pedro is changing the geometrical model to set the FM pmts to an angle of 15 deg to the field. Should be finished by Fri or Mon.
- Will post .iges files from SOLID MODEL where we can download them an enter them into our 3D mechanical model.
- Pedro: Noted that measurements by Hall D group are incomplete and should be filled before final decisions are taken. Elton noted that the NIM article from KLOE has additional information that might fill in these gaps.
- The plots of the Bfield which were posted can be checked against the ROOT file which USM is using as a basis for setting the angle of the FM pmts.
- Light Guide Simulations
- George emphasized that prototypes must be built and measured to check the absolute normalization of transmission.
- From last wg meeting: Elton had confirmed the high geometric efficiency (>98%) of these light guides. Inclusion of the attenuation length reduces the efficiency to about 57%.
- The changes to the geometry are not expected to change the geometrical efficiency very much, but this needs to be confirmed.
- Discussions on MOU with USM