Timing measurements of Silicon Photomultipliers (SiPM) at the picosecond level were performed at Fermilab. The core timing resolution of the electronic measurement technique is approximately 2 picoseconds. The single photoelectron time resolution (SPTR) was measured for the signals coming from the SiPM's. A SPTR of about one hundred picoseconds was obtained for SiPM's illuminated by laser pulses. The dependence of the SPTR on applied bias voltage and on the wavelength of the light was measured. A simple model is proposed to explain the difference in the SPTR for blue and red light. A time of flight system based on the SiPM's, with quartz Cherenkov radiators, was tested in a proton beam at Fermilab. The time resolution obtained is 35 picoseconds per SiPM. Finally, requirements for the SiPM's temperature and bias voltage stability to maintain the time resolution are discussed.

We report on work to develop a system with about 100 picoseconds (ps) time resolution for time of flight positron emission tomography [TOF-PET]. The chosen photo detectors for the study were Silicon Photomultipliers (SiPM's). This study was based on extensive experience in studying timing properties of SiPM's [1-4]. The readout of these devices used the commercial high speed digitizer DRS4 [5]. We applied different algorithms to get the best time resolution of 155 ps Guassian (sigma) for a LYSO crystal coupled to a SiPM. We consider the work as a first step in building a prototype TOF-PET module.

The purpose of this work is to improve the reconstruction techniques of the decays of the particles that contain charm in the quark composition using the information of the Target Silicon Detector of the experiment E831 (FOCUS). That experiment runs during 1997 to 1998 in Fermilab National Laboratory. The objective of the experiment was improving the understanding of the particles that contain charm. Adding the Target Silicon Detector information in the reconstruction process of the primary vertex the position error. This reduction produces an improvement in the mass signal and the knowledge of the charm particles properties. This ad to the possibility's that in other analysis will use the techniques developed in this work.