[Halld-cal] Minutes Cal Working Group Meeting Jul 5, 2011

[Elton Smith]

Dear colleagues,

Below are the minutes to our meeting this morning. I will add them to 
the wiki when it becomes available.

Cheers, Elton.


Minutes Cal Working Group Meeting Jul 5, 2011
=============================
''Attending: Zisis, Andrei (UofR); Elton, John, Beni, Yi (Jlab); Will 
(USM); Christina, Stratos (Athens); Matt (IU)

# Announcements
#* Due to the JLab "cyber event," the meeting was held using ReadyTalk 
conferencing
# Bcal Update
#* Modules 41 and 42 will be completed next week
#* Expect to complete modules through 46 this summer, leaving only 47 
and 48 for the reduced workforce this fall
#* Scheduled from machining next batch of 4 modules will be decided this 
week
#* All lead has been moved from cold storage to the lab. Will reserve 
latest batch of lead for module 49
#* Fiber shipment is delayed but expected this week
#* SiPM PDE test setup has been upgraded and will be hooked up to a DAQ 
system borrowed from T2K colleagues
# Monitoring
## Bcal
##* New LEDs have arrived from UofR and are expected to be ones used in 
final system, if tests are successful
##* To test the new LEDs, a mounting board will be coupled to an 
existing electronics board will be coupled to simulate the final 
production board (but be twice as thick)
##* The LED system will be tested on the new trapezoidal guides.
##* We discussed the cabling going to the control board. The decided on 
the following division, based on further compatibility checks: JLab 
would be responsible for the cable to the readout enclosure and the 
penetration. Athens would propose the connector and cable to run between 
the control board and the patched connector.
## Fcal
##* Design requires a decision on how often the 4 colors will be pulsed 
and interval between pulses
##* Elton suggested that the different colors be supplied from different 
(programmable) LV sources, so switching should not be a problem
##* John asked about the range of bias voltages: expect 6-15 V.
# USM update
## Electronics
##* Progress on testing of big electronics board.
##* Populating a second big board with components for further testing
##* Modifying the design of the big board to increase modularity by 
moving some circuitry to a daughter board
## Light guides
##* Two guides were sent to Athens last week. They should have arrived, 
but it appears there is a problem with the address
## SiPM contract with Hamamatsu
##* PO has been issued to Hamamatsu. Hamamatsu has sent USM a proforma 
invoice. Invoice is in the process of being co-signed by the rector, so 
payment can be issued. Once that cycle is complete, Hamamatsu will sign 
the JLab mod to drop 2800 units from their contract.
# Fcal update
#* Quiet last couple of weeks with John and Paul on vacation. They are 
both back
#* Paul will continue investigating the few base failures. Final 
schedule for the production run is complete
#* JLab has been reviewing IU drawings and has promised feedback by tomorrow
#* PO has been issued for the CAN-ethernet controllers. Will send one 
unit to JLab together with a home-built power supply.
# Readout assembly
#* Mechanical cooling prototype has been built and is used to measure 
cooling scheme.
#* Elton reported that JLab is trying to setup the readout for SiPM 
production testing. We need 8 VME CAEN 792 QDCs, but at the moment we 
have only identified 5. Asked Will to send information regarding the USM 
multiplexing scheme for evaluation.
# Beam tests
#* UofR would like to instrument a baby cal with a production SiPM 
readout for testing in a realistic beam environment.
#* Eugene had promised to touch base with Volker on general guidelines 
for tests in Hall B.
#* If we decide to move forward on this project, UofR could easily build 
a baby cal in early Sep for use in the tests
#* Matt suggested that the Bcal be mounted vertically allowing one axis 
of rotation to position module perpendicular to incident degraded 
electron "beam".
#* Matt summarized the status of Fcal beam test preparations
#** Kei has investigated the space in Hall B during a recent visit
#** Tagger geometry and particle trajectory reconstruction is being 
obtained from Richard and Franz
#** Concern about "clean" electron events, as many particles may 
interact first in the tagger hodoscope.
#** To alleviate this concern, they are planning to build a small 
(10x10cm2) scintillators to be used for triggering and identifying the 
electron beam energy (~1%). Use of this scintillator will also eliminate 
the need to access Hall B tagger information.
# General:
#* Could run Fcal and Bcal roughly at the same time by mounting both 
systems in a row, or one could reuse the same space by alternating 
detectors. Both would use "final" electronic modules, including FADCs.



-- 
Elton Smith
Jefferson Lab MS 12H5
12000 Jefferson Ave
Suite #16
Newport News, VA 23606
(757) 269-7625
(757) 269-6331 fax