Aug 5, 2010 Calorimetry
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Teleconference Time: 11:00 a.m. EDT
- ESNET and EVO session
- Phone in CC F326 is 757-269-6337
- Phone in the Regina Videoconference Suite is 306-585-4204
- Phone only if requested:
- +1-800-377-8846 : US
- +1-888-276-7715 : Canada
- +1-302-709-8424 : International
- then enter participant code: 77438230# (remember the "#"). Phone line by request only.
Contents
Items for followup from previous meeting(s)
- Monitoring
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USM: Send drawings of guides to be machined (soon). Send 4 unpolished guides to UofR and 2 unpolished guides to Athens. -
Bcal: Testing to see if LED sources can be viewed by pmts on both sides of the module (UofR/UofA).
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- Fcal
- Decision on rad hard detectors
- Ashot to send type of Hamamatsu pmt used for PRIMEX
- Elton and Ashot to meet and resolve any discrepancies between the simulations.
Discussion of Options for Radiation-Hard Insert
Options for Radiation-Hard Insert
Tentative Agenda
- Announcements
- Review of Action Items
- FCAL
- Construction status
- To shashlyk or not to shashlyk.
- BCAL
- Construction Status
- Cosmic-ray normalization runs
- Update on SiPM radiation hardness (Elton)
- Simulations
- Other Updates
Minutes
Attendees: Matt, Ryan (IU); Elton, Beni, Tim, John, Eugene, Hovanes (JLab); Zisis (UofR); Will, Pedro (USM)
- Announcements
- Zisis will run the next working group/Bcal reaodut meetings.
- Review of Action Items
- Calibration
- Athens has received light guides from USM, polished them and collecting data. Results will be reported at the collaboration meeting.
- FCAL
- Construction status
- Progress smooth according to plan: 1300-1400 welds on straps, will check wrapping/packaging shortly
- Redesign of Cockcroft-Walton bases proceeding
- Once redesigned, 10 prototypes will be made for checking
- Begin planning for base/electronics review. Schedule has slipped by one month, which can be recovered. But do not want further slippage
- General caution: Lead times for electronic components are stretching out, many from 12 to 60 weeks. Placing orders for long-lead items.
- To shashlyk or not to shashlyk.
- No update
- Construction status
- BCAL
- Construction Status
- Building modules 15 and 16, expect completion by middle of next week. Mods 13-16 will then go into the machining queue
- Slight snag in carpentry for next set of crates, but should be resolved
- Mods 9-12 shipped Tues, should arrive tomorrow
- Cosmic-ray normalization runs
- Normal operation in lab. Five points of cosmics completed. Cross checks underway. Report updated normaliation in two weeks.
- Construction Status
- Update on SiPM radiation hardness (Elton)
- Description of expected doses for downstream SiPMs. (Upstream devices will receive about 5 times lower rate).
- Time @10^8 g/s for Dark rate to increase x10 is 3.25 years (10^7 s/year) x factors
- This corresponds to a fluence of 10^9 1MeV neutron eq/cm^2.
- factors = self-annealing x cooling x DR/10 x temperature annealing
- self-annealing = 2 (Measured in HallA irradiated samples, needs checking for cooled AmBe irradiated samples)
- cooling = 3 (For non-irradiated samples DR -> 0.3 DR between 20 and 5 deg C, needs checking for irradiated samples)
- DR/10 = 0.5, Study of degradation of threshold with dark rate. See Media:Plot threshold1.png with reference to Matt's resolution calculations
- temperature annealing = ? (additional annealing gains by raising temp ~ 80 deg C, needs checking)
- Comments
- Eugene: There is a single 1x1 mm2 unit which has an anomalous x4 higher rate increase than others tested. It will be re-checked next week.
- John: Consider changing out sensors after 3 years? Zisis: Possibly cool to -10 deg? Matt: Run at 5x10^7?
- Matt: Cautioned that calculations of resultion do not include summing. Elton: This could increase effective dark rate contribution to shower, but lower thresholds/sum.
- Zisis: Relative to FMs: concerned about mechanical complexity as well as sensitivity of pmts to changes in field
- Eugene: Calculations assume that both upstream and downstream have the same rate. Lower rates in upstream sensors could reduce dependence on radiation damage.
- Further work
- UofR: Complete cosmic-ray energy calibration.
- IU: a) take into account 5 times lower rate in upstream compared to downstream b) geometry for summed units
- JLab: Complete testing of radiation damage to sensors, temperature dependence, etc.
- Simulations
- Other Updates