Speaker
Mikhail Danilov
(ITEP)
Description
The CALICE collaboration is presently constructing a test hadron calorimeter
(HCAL) with 8000 scintillator tiles read out by novel Geiger mode semicon-
ductor photo detectors - Silicon Photomultipliers (SiPMs). This prototype is
the first device which uses SiPMs on a large scale. We present the design of
the HCAL including scintillator tile - WLS fiber - SiPM systems, mechan-
ics, electronics and calibration systems. We report on measured properties of
more than 10 thousand SiPMs and more than 6.5 thousand tile-SiPM systems.
We present a detailed discussion of the SiPM efficiency, gain, cross-talk, and
noise rate dependence on bias voltage and temperature including the spread
in these parameters. We analyze the reasons for SiPM rejection and present
the results of the long term stability studies of more than 5000 SiPMs. The
first measurements of the SiPM radiation hardness are presented. We com-
pare properties of SiPM with the properties of similar devices MRS APD and
MPPC and discuss their advantages for the more than a million channel ILC
calorimeter. Preliminary results of the Calorimeter beam tests at CERN are
presented which represent the first operational experience with a large system
based on such novel photo-detectors.
A scintillator strip with SiPM readout TCMT prototype is also being con-
structed within the CALICE collaboration to complement the combined
ECAL and HCAL test beam program. The properties of this device are pre-
sented. A possibility to make the tiles thinner or to read them without WLS
fiber has been studied, and the time resolution of scintillator counters with
WLS fiber and SiPM readout has been measured.
Author
Mikhail Danilov
(ITEP)
