Minutes of the forward endcap EMC eZuce SRN meeting, 26th of September 2016, 14:00-15:00

Presence:

• Basel: Werner
• Bochum: Cathrina, Claudius, Fritz-Herbert, Malte, Matthias, Patrick, Tobias H., Tobias T., Tom
• Bonn: Christoph, Merlin
• Giessen: Hans
• Groningen: Myroslav
• Stockholm: -
• Uppsala: Pawel
• GSI: -

VPTT Preamps:

• Agreement on total number of preamps needed for forward endcap (incl. spares): 900 pieces (225 'high gain' (0.89 V/pC, 488 "mid gain' (0.82 V/pC), and 187 'low gain (0.7 V/pC)
• That is we need 100 more VPTT preamps than already produced
• Werner will talk to Bernd about the costs and will check how to arrange preamp production
• Much to our regret Werner will leave PANDA end of December!

Glueing Issues:

• The unsolved glueing problem still prevents us from starting subunit manufacturing
• Some discussion with the Giessen colleagues last week: We will try their glueing technique (no vacuumizing of glue, high pressure curing instead) with our crystals and compare the coupling strengths
• Much improvement comes from usage of special primer before glueing. Need to test for transparency and radiation hardness (Giessen)

VPTTs:

• 150 units still need to be B-field gain loss measured. This will start soon and is expected to last 2 weeks.
• About the same number of tubes needs to be gain measured with 1000 V supply voltage in Bochum. Some of the tubes currently located in Bonn (need to check...). Measurement setup is in preparation...

ADC boards:

• Order of manufacturing: offers from possible manufacturers awaited, tendering process started
• Myroslav: will there be test pieces manufactured before production of full batch? Pawel: 1-2 test pieces
• Malte: How much time left to decide on shaper stage values? Pawel: 5-6 months
• Bochum will start work on shaper stage tests: simulation of pulses (charge injection to Basel preamp) with rise time variation according to what is seen on cosmics events

Bonn Cosmics Setup:

• The test subunit equipped with two crystals with two APDs each, glued with primer treated crystal surface and equipped with latest Basel preamp version works fine
• Waiting for preamp output signal amplitudes resulting form vertically crossing muons in the crystals to confirm necessary APD preamp gain