DANSS is a highly segmented 1m^3 plastic scintillator detector. Its 2500 scintillator strips have a Gd loaded reflective cover. Light is collected with 3 wave length shifting fibers per strip and read out with 50 PMTs and 2500 SiPMs. The DANSS will b
e installed under the industrial 3 GW reactor of the Kalinin Nuclear Power Plant at distances varying from 9.7m to 12.2m from the reactor core. Tests of the detector prototype DANSSino demonstrated that in spite of a small size (20x20x100 cm^3) it is quite sensitive to reactor antineutrinos, detecting about 70 Inverse Beta Decay events per day with the signal-to-background ratio of about unity. The prototype tests have demonstrated feasibility to reach the design performance of the DANSS detector. The DANSS experiment will detect about 10 thousand antineutrino events per day with a background below ~1%. Detector will be calibrated every day and its position will be changed frequently to reduce systematic errors. These features will provide a high sensitivity to reactor antineutrino oscillations to sterile neutrinos, suggested recently to explain a so-called reactor anomaly. Data taking will start already next year.
The CALICE collaboration is presently constructing a test hadron calorimeter (HCAL) with 7620 scintillator tiles read out by novel photo-detectors - Silicon Photomultipliers (SiPMs). This prototype is the first device which uses SiPMs on a large scal
e. We present the design of the HCAL and report on measured properties of more than 10 thousand SiPMs. We discuss 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. The first measurements of the SiPM radiation hardness are presented. We compare properties of SiPM with the properties of similar devices, MRS APD and MPPC. A possibility to make the tiles thinner and to read them out without WLS fibers has been studied.
