Visit to CALICE ECAL testbeam (by Shinshu)
at DESY, 16th – 19th October 2012
Samir Arfaoui &Erik van der Kraaij
30th October 2012
Setup @ DESY
30th October 2012Erik van der Kraaij, CERN LCD 2
Scintllators: • 45x5x2mm strips are used by the japanese• they recycled them from a previous prototype tile
and had the strips cut from it• no clear supplier for their scintillators
Read-out:• Hammamatsu MPPC (model?)• Their layer has 144 tiles (36x4) with
4 HBU and 4 SPIROC2b chips. • On top, 3 cards:
– DIF (LEMO for Spill signal, TTL signal, and Reset)
– Calibration board (LED)– Data-out board with USB connector
Setup @ DESY
30th October 2012Erik van der Kraaij, CERN LCD 3
Trigger• Self-trigger: when one tile has a hit over threshold, all the
tiles on the same HBU (36 total) are read out.• Validation mode: a crossed scintillator pair in coincidence for
external trigger, upstream of the prototype. If validation signal is sent within clock-cycle of self-trigger, data is flagged as validated– Helpful to get rid of noise self-triggers– Japanese team did not manage to operate in this mode
Front-end: SPIROC2b • Seems to be a black box…• Memory: 16 events and 0.5-1s for read-out• Complex configuration (Labview programs by DESY people)
not a good idea for early CERN lab setup…• Need expertise (LAL? DESY?) for initial setup/operation
– Japanese team lacked it, slowed them down greatly
Setup @ DESY
30th October 2012Erik van der Kraaij, CERN LCD 4
Came in this morning from Katsu• They managed to perform measurements at various positions in
the shower
Setup @ CERN
30th October 2012Erik van der Kraaij, CERN LCD 5
Need for CERN lab:• at least 3 scintillators: 2 for coincidence trigger to get rid of
the noise and the one under test• collimated radioactive source• SiPM + decoupling circuit => Picoscope• Hamamatsu MPPCs from DESY (thank you)
– 10 of them in Samir’s office (+ a couple of reflective foil sheets)
• Black box with cooling (or at last temperature monitoring) and shielding
Readout options (from Christian)• EasiRoc. High level of integration. 128+ channels. ADC, no
TDC. Could be made available by Aachen.• SPIROC + testboard at OMEGA. Details still to clarify.• CAEN VME module (similar to Erika @ DESY). PreAmp, ADC,
TDC. How to bias MPPCs? CERN pool?• Picoscope. 4 channels. Bias via Keithley. CERN pool?