PID Cherenkov Session at CM 21/3

Minutes of the PID-Cherenkov group

Simon Bodenschatz, Uni Giessen, DIRC and GCS status update.
The first prototype readout card for arrived. Its power consumption of
about 10 Watts is mainly driven by the infrastructure for the 5 TOFPET2
asics, like the FPGA, optical transceiver and others. Each TOFPET2
asics has a power consumption of 10 mW/channel and 64 channels. Also the last
activities for the Giessen Cosmic Station were shown.

Carsten Schwarz, GSI Darmstadt, Status of the Barrel DIRC DAQ
Carsten showed the next plans for the Barrel DIRC readout. It is planned
to study the cooling of the DIRICH cards by air and to measure the amount of
needed air. Also the power routing for the many low voltages and large
currents was discussed. The best solution would be to get with 48 Volts
into the solenoid and to regulate down the voltages with magnetic hard
DC-DC converters like the FEAST from CERN.

Greg Kalicy, CUA Washington, Mapping the focal plane for a 3-layer lens
Greg showed the optical measurement setup in Washington, where the shape of
the focal plane of lenses immersed in oil can be measured. The measurements
are not only for the Barrel DIRC at PANDA but also for the planned one at EIC.
He showed measurements which agree well with Geant4 simulations.

Daniel Miehling, FAU Erlangen, Update on Lifetime Measurements and the
strange behavior of the latest Photonis tubes
The latest results for the aging studies of MCP-PMTs were shown. Most sensors
with ALD coated MCPs have lifetime larger than 5 C/cm². He discussed the
so called escalations, the intermittent wild firing of tubes, which
the latest PHOTONIS tubes have shown. Photonis is aware of this effect and
the tube 105P541 was sent back for further tests of these escalations.

Steffen Krauss, FAU Erlangen, First results of the B-field measurements
Measurements of MCP-PMTs within a dipole magnet in Juelich were done
in a magnetic field up to 1 Tesla. As expected, recoil distributions
change significantly at high B-fields and the pixel position is better defined.
for the measurement of after-pulsing there is a difference between
scope data and TDC-measurements due to the finite deadtime of the TDC channels.
This effect needs more investigations.

Merlin Boehm, FAU Erlangen, TRB/DiRICH in the magnetic field
He measured inside a 3T MRI scanner the behaviour of the readout cards.
Besides of the expected failure of DC-DC converters a drop in the
amplification of the analog part was observed. The input transformer of
the amplifier is not the reason. The inductance in the collector path of
the HF-transistor is the next most probable suspect.