General Meeting Summary 2/26/15

IDAHO TESTS (17 - 20 FEBRUARY)

• Discussion of the test report and the main results

• Crystals appear to be able to handle high doses at high dose rates
• Crystals properties are sensitive to temperature. In extreme cases, e.g., rise of temperature of more than 0.5 degrees/min, structural damage may occur.

• Discussion of how to reconcile Idaho results with Rainer's results

• Rainer's radiation method is different (e.g., particles, energy, radiation uniformity) and so a direct comparison of the two data sets may not be possible
• Next step: check if can send subset of the crystals to Rainer for testing in his setup
• Action items: 1) Check on shipping crystals from Idaho to JLab (Carlos), 2) Check with Rainer on possibilities to test crystals at Giessen (TH), 3) Check on shipping crystals from JLab to Giessen (Hamlet, Rolf)

• Discussion of further crystal measurements and tests at JLab in parallel to tests at Giessen

• Crystal recovery: depends on temperature (see slide 18 in Rainer's talk from Nov 2014 NPS collaboration meeting). For further studies of radiation hardness may need to consider a temperature stabilized system.
• Crystal light yield: Light yield depends on temperature, e.g., Rainer's measurements were conducted in a temperature stabilized system at 18 degrees (see his talk from Nov 2014 NPS collaboration meeting). A temperature stabilized system could be beneficial for these tests.
• Transmittance and timing

• Discussion of testing PWO crystals at Idaho for selection purposes in the future

• In general seems possible. Irradiation procedure for one crystal takes about 20 minutes
• Temperature stabilizing system required to eliminate uncertainties in radiation hardness due to temperature dependence. Such a system would also help with increasing the dose rate without causing structural damage to the crystal.

• Discussion of testing the crystals at Caltech

• Should still be done
• Would use the same crystals that have been tested at Idaho and with Rainer's setup

ITEMS FOR NEXT MEETING:

• Crystal tests in Giessen

• Crystal studies at JLab

• Other...

NEXT MEETING: THUR., 19 MARCH 9:00 AM (EST)