A simple and robust method to study after-pulses in Silicon Photomultipliers

The after-pulsing probability in Silicon Photomulti- pliers and its time constant are obtained measuring the mean number of photo-electrons in a variable time window following a light pulse. The method, experimentally simple and statistically robust due to the use of the Central Limit Theorem, has been applied to an HAMAMATSU MPPC S10362-11-100C

Dual-readout fibre-sampling calorimetry with SiPM light sensors

In this paper we present the most significant testbeam results of a dual-readout fibre calorimeter module equipped with silicon photomultipliers (SiPMs) to sense the scintillation and Cherenkov light signals. The main challenges of this detector are the minimization of the optical crosstalk between the two signals and the potential saturation of the digital SiPM-based readout. Both topics have been investigated with encouraging results. As a by-product of this extremely granular readout, the lateral profile of electromagnetic showers was sampled with an unprecedented precision close to the shower axis and significant differences were observed between the scintillating and Cherenkov signals

Characterisation of a silicon photomultiplier based oncological brachytherapy fibre dosimeter

Source localisation and real-time dose verification are at the forefront of medical research in brachytherapy, an oncological radiotherapy procedure based on radioactive sources implanted in the patient body. The ORIGIN project aims to respond to this medical community's need by targeting the development of a multi-point dose mapping system based on fibre sensors integrating a small volume of scintillating material into the tip and interfaced with silicon photomultipliers operated in counting mode. In this paper, a novel method for the selection of the optimal silicon photomultipliers to be used is presented, as well as a laboratory characterisation based on dosimetric figures of merit. More specifically, a technique exploiting the optical cross-talk to maintain the detector linearity in high-rate conditions is demonstrated. Lastly, it is shown that the ORIGIN system complies with the TG43-U1 protocol in high and low dose rate pre-clinical trials with actual brachytherapy sources, an essential requirement for assessing the proposed system as a dosimeter and comparing the performance of the system prototype against the ORIGIN project specifications

THE ALICE SILICON PIXEL DETECTOR (SPD)

G. ANELLI, F. ANTINORI, A. BOCCARDI, M. BURNS, I. A. CALI, M. CAMPBELL, P. CHOCHULA, R. DINAPOLI, D. ELIA, F. FORMENTI, A. O. GINER, M. KRIVDA, V. LENTI, V. MANZARI, M. MOREL, P. NILSSON, A. PEPATO, P. RIEDLER, R. SANTORO, G. STEFANINI CERN European Organization for Nuclear Research, CH-1211 Geneva 23, Switzerland Universita degli Studi di Padova, I-35131, Padova, Italy Dipartimento IA di Fisica e Sez. INFN di Bari, I-70126, Bari ,Italy Slovak Academy of Sciences, SK-04353, Kosice, Slovakia ASP-Associazione per lo Sviluppo Scientifico e Technologico del Piemonte, I-10133 Torino, Ital