General Meeting Summary 3/27/14

NPS PROTOTYPE STATUS:

• HV dividers: Electronics group assembled components, but test results are different compared to last year's dividers. Investigations ongoing.

• Hamamatsu PMTs have been delivered and initial gain tests look good

• Made preliminary tests with IR sensitive LEDs. Results of intensity tests show good intensity for curing applications. Further tests will include additional absolute intensity measurements to check reproducibility, checks of the PMT sensitivity to IR light, e.g., testing quantum efficiency before and after illumination with IR light.

• Crystals: preparing for transmittance measurements before and after irradiation.

• Prototype frame: based on studies of weight, cost, thermal, and residual radiation will use Copper for the frame material. Weight will be on the order of 10 kg.

• Light source for Light Monitoring System for combined PbWO4/PbF2 crystal matrix: based on transmission measurements of PbWO4 and PbF2 crystals find that transmittance for both crystals saturates above 400 nm. So using a common light source with wave length ~>500 nm should be fine. Transmittance measurements were done for PbF2 in longitudinal and transverse dimensions. For PbWO4 only one dimension was measured to check wavelengths as this is not a crystal which would actually be used.

• Output pulse timing of PbWO4 and PbF2: can be checked in detail with prototype

DISCUSSION ABOUT ELECTRONICS TESTS (ALEX)

• Got fADC electronics and should have test setup ready soon

• Discussion of effect of 1-4 ns jitter on 250 MHz on pulse shape using the PbF2 reference pulse shape and shifting the base of the integral. Results suggest that fluctuations are small. Further tests will be done with actual hardware. This will allow to include the background to constrain the fit.

• Additional studies to determine the effect of lower sampling rate on energy resolution and timing are ongoing using elastic data. Results will be presented at an upcoming meeting.

CALOR 2014 - PWO DISCUSSION

• General idea of discussion is to develop a common strategy on how to deal with present PbWO4 vendor situation, e.g., need for R&D and manufacturing

• Would be good to have general documentation of requirements from all interested groups and what they are based on, e.g., properties that make PbWO4 radiation hard and general direction

STATUS OF RCS/pi0 PROPOSAL

• Simulations are ongoing and being finalized in collaboration between WACS and photoproduction

• Target date for submission is June. Would be nice to circulate a (rough) draft to NPS collaboration in May for feedback

ITEMS FOR NEXT MEETING:

• NPS design and prototype

• Electronics tests

NEXT MEETING: THUR, 17 APRIL at 9AM (EST)