Minutes of the Forward Endcap EMC SADC Crate Design Vibe/eZuce meeting, 15th of June 2020, 14:00-15:15

Presence:

• Bochum: Tom, Matthias, Claudius, Fritz-Herbert, Malte, Miriam, Tobias H., Tobias T., Sebastian, Thorsten
• Basel: -
• Bonn: Christoph, Johannes
• Groningen: -
• Uppsala: -
• Giessen: Markus, Hans-Georg

Submodule Manufacturing:

• Exchange of submodules (pick-up of finished modules in Bochum, receive of ones that need repair from Bonn) foreseen for Wednesday this week (Christoph and Tom)

HV distributor board:

• Bochum would like to get a working distributor board ("Schmidt board") in order to perform submodule readout and HV setting tests of the "Jülich" test stand currently build up in Bochum
• There are four boards operated in Bonn, one more board may be finished soon to be given to Bochum, some more boards are foreseen to be produced anyway
• There is some drift and slow settling effect of APD-HV setting with the distributor boards. A change in the voltage divider resistance dividing APD HV to ADC readout by a factor of 5 (20 M to 100 MOhms) reduces the time of stabilization (effect of resistance change due to power dissipation?)
• However, need to check whether increasing voltage divider resistance does increase susceptibility to surface currents on PCB, maybe sealing necessary (rad. hard - Elastosil?)
• There is also a long term drifting (in the order of 20 mV in 2 days) whose origin is not clear yet

Takeover of KVI work of Peter Schakel:

• Who will be a suitable/willing/available candidate to take over the work preveiously done by Peter Schakel (KVI) for the SADC FPGA readout firmware? (Malte?, Johannes?)