Sep 4, 2012 Readout

Teleconference Time: 11:00 a.m. EST

• ESNET (Number is 8542553) and EVO session (GlueX Calorimetry meeting room)
• Phone connection only upon request.
  • +1-866-740-1260 : US and Canada
  • +1-303-248-0285 : International
  • then use participant code: 3421244# (the # is needed when using the phone)
  • OR from www.readytalk.com type access code 3421244 into "join a meeting" without the # (you need java plugin)

Participant Direct Lines

• JLab Phone: in CC F326 is 757-269-6337 (usual room)
• JLab Phone in CC L207 is 757-269-7084
• Phone in the Regina Videoconference Suite is 306-585-4204
• Athens Phone: in Christina's office is 011-30-210-727-6947

Items for followup from previous meeting

1. SiPMs (USM)
   • Add expected completion date for each line in the table based on progress.
   • Provide histograms of all measured units for each specification at T=20 deg C and V=1.2 V above breakdown.
   • Send dump of data base. Provide the dump on a disk with the next shipment of SiPMs
2. LIght guides
   • Check the light guides with the JLab template before shipping to verify compliance. Check with JLab if the units do not pass.

Tentative Agenda

1. Announcements
2. Review of Action Items
3. Update from Athens: monitoring (Media:BCAL_LED_prog_3_2012.pdf)
4. Update from USM
   1. SiPM Update (Javiera)
   2. Parameters at 1.2 V over BDV (Orlando)
5. Status of testing at JLab
6. Beam Tests, Cosmics
7. Simulations
   • BCAL Simulations (David L.)
8. Other

Minutes

Attendees: Orlando, Javiera, Fransisco, Hayk, Will (USM), Christina (Athens), David, Tim, Beni (JLab), Andrei, Zisis (Regina)

1. Announcements: None.
2. Review of Action Items
   1. Histograms: Introduction will be given today and histos shown, while discussion will take place next week.
   2. DB dump: It will be sent along with the next batch of MPPCs, due to leave tomorrow (Sep 5) from Chile.
   3. LG compliance: Chile is implementing this; dimensional data was sent to JLab for the 80 LGs in transit.
3. Update from Athens
   1. Very good progress: all boards stuffed, 160 mini boards per sheet, 4000 total (~100 spare). Glue to metal side should go well using our established process. Enough LEDs for a few modules could be shipped in ~10 days if all goes well.
   2. LED test: each LED will be measured at least 5 times (perhaps as much as 10x) to establish the RMS. At 12V bias the LED light is visible to the eye.
4. Excel Reports: the LED numbers go from 1-4000 and the flex from 1-390.
   1. Question from CK: where are the 80 LGs? Answert is that they are stuck in customs. After they are received and check by JLab, 162 more will be shipped.
5. Update from USM
   1. Javiera: The next 520 MPPCs should leave Chile tomorrow for JLab. The remaining 360 from Hamamatsu will be arriving soon.
   2. Orlando: The data shown is for the 1000 units sent to JLab plus 60 additional ones that had been measured as well. Only the 1.2 V and 20 deg data is shown. All plots (except those on the last 4 pages) show as error bars the error of the mean. The dark rate is defined as the ratio of 1 pe / pedestal. Gate is the standard one used for all tests. The xtalk appears to be quite high. There is a feeling that perhaps 1.2 V is too high, and that 1.0-1.1 V may be a better choice. This will be discussed next week after everyone absorbs the information on Orlando's talk.
6. Status of testing at JLab: nothing to report.
7. Beam Tests, Cosmics: final checks on SiPM overbias scan using a UV LED laser. The results will be presented and discussed next week.
8. Simulations
   • David L.: The new mechanism using the time-evolved spectrum has been checked in the code. The new setup mimics the actual electronics signals. The new code is not used by default; if checked out two files need to be modified to turn it on (See David's slides). Both old and new info can be written out. The TDC and ADC thresholds were also separated, and the ADC one was brought down to 4mV. The ADC and time info from the flash FPGA (with 4ns Gaussian smear) are booked in separate data objects to those of the F1 TDC. David will check what the code does for the outer layers that have no TDCs. The simulated resolutions are shown on p.4. No floor term appears despite 1.3% smear. When the floor term is fixed at 1.3% the fits still look good. When dark hits are turned off, resolution goes down, still above "legacy" 4.5%/sqrt(E) and noise term persists at 1% for forward angles dropping to 0.2% at 30 deg. A 4 GeV point from the reconstructed files by IU did not make it onto the plots, since it failed the cuts of one shower/event with more than one block hit. Algorithm needs more tuning. Shower is linear (see p.5). No calibration constant is applied before 100keV cut. It was mentioned that single-end hits need to be look at in the future.
9. Other: no other business.