L. Quadrani

Novel Silicon Photomultipliers for PET Applications

Silicon photomultipliers (SiPMs) with quantum efficiency maximized for a wavelength between 420 and 470 nm have been developed at ITC-irst Trento (Italy), and are being tested for their application in the construction of a ultra high resolution small animal PET tomograph. The devices have an area of 1 mm times 1 mm and 625 microcells. The breakdown voltage is around 30 V, and the gain of the order of 106. The intrinsic timing resolution is 70 ps rms at the single photoelectron level. The first tests as readout for scintillators show an energy resolution of 21% FWHM with Na-22 employing LSO crystals. The first matrices of SiPMs have been produced and are being tested.

Search for Dark Matter in Cosmic Rays with the AMS-02 space spectrometer

The cosmic rays spectrometer AMS-02 will be placed on the ISS Space Station in April 2011 and should take data for at least 10 years. After a short review of the impressive observational data collected in the last few years by satellites and underground experiments in the quest for Dark Matter (DM), we describe the AMS-02 space spectrometer with its powerful particle identification capabilities. The performances of the experimental apparatus and the perspectives opened by this new powerful observational instrument for the DM search will be briefly reviewed. In particular the extension at the TeV scale of the positron and electron spectra with high statistical significance well beyond the PAMELA results will hopefully clarify the quest for Dark Matter evidence in cosmic rays. Finally the present status of the AMS-02 payload for the Shuttle transportation and installation on the International Space Station, and the implementation of the Control Center for data collection and analysis is reviewed.

Performances and space qualification tests of the AMS time of flight

The AMS-02 time of flight system is in construction at the INFN laboratories of Bologna and it will cover an angular aperture to match the need of the AMS-02 spectrometer. The counters of the four TOF planes have a time resolution of 150 ps for 1 mip and of 60-70 ps for Z = 10. The detector will give the fast trigger to the DAQ of the whole experiment and will perform up/down particle separation at a level of 10/sup -9/; it will also measure the charge of the particles passing through, up to Z about 20. The space operation for at least three years imposes several requirements on the TOF. For this reason some space qualification tests have been done and their results are shown.