787 research outputs found

    First characterization of the Hamamatsu R11265 multi-anode photomultiplier tube

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    The characterization of the new Hamamatsu R11265-103-M64 multi-anode photomultiplier tube is presented. The sample available in our laboratory was tested and in particular the response to single photon was extensively studied. The gain, the anode uniformity and the dark current were measured. The tube behaviour in a longitudinal magnetic field up to 100 G was studied and the gain loss due to the ageing was quantified. The characteristics and performance of the photomultiplier tube make the R11265-103-M64 particularly tailored for an application in high energy physics experiments, such as in the LHCb Ring Imaging Cherenkov (RICH) detector at LHC

    Very low noise AC/DC power supply systems for large detector arrays

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    In this work, we present the first part of the power supply system for the CUORE and LUCIFER arrays of bolometric detectors. For CUORE, it consists of AC/DC commercial power supplies (0–60 V output) followed by custom DC/DC modules (48 V input, ±5 V to ±13.5 V outputs). Each module has 3 floating and independently configurable output voltages. In LUCIFER, the AC/DC + DC/DC stages are combined into a commercial medium-power AC/DC source. At the outputs of both setups, we introduced filters with the aim of lowering the noise and to protect the following stages from high voltage spikes that can be generated by the energy stored in the cables after the release of accidental short circuits. Output noise is very low, as required: in the 100 MHz bandwidth the RMS level is about 37 μVRMS (CUORE setup) and 90 μVRMS (LUCIFER setup) at a load of 7 A, with a negligible dependence on the load current. Even more importantly, high frequency switching disturbances are almost completely suppressed. The efficiency of both systems is above 85%. Both systems are completely programmable and monitored via CAN bus (optically coupled)

    A multichannel data acquisition system for bolometer detectors based on microcontroller Cortex M3 architecture

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    We present the first prototype of a custom Data Acquisition System for bolometer and scintillating bolometer detectors. It consists of a board controlled by a Cortex M3 microcontroller coupled with a 8 channels Sigma/Delta 24 bit ADC. The large number of bits allows having at the same time a high dynamic and a high resolution at low threshold, in order to separate very low energy events. Each board accommodates 8 input channels sampled simultaneously with a maximum rate of 50 kHz. Converted data are read by the microcontroller and sent to the remote controller using the TCP/IP or UPD communications protocol. The microcontroller also manages the board configuration. The board, exploiting the microcontroller flexibility, is fully programmable, it can work in different running modes and it can perform common data processing algorithms on the acquired data (first level trigger, digital filtering, zero suppression, FFT, etc). In this work we present tests and characterizations about this first custom data acquisition system. The results are the starting point in order to design the final prototype. © 2012 IEEE

    MARE-1 in Milan: Status and Perspectives

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    The international project MARE (Microcalorimeter Array for a Rhenium Experiment) aims at the direct and calorimetric measurement of the electron neutrino mass with sub-eV sensitivity. Although the baseline of the MARE project consists in a large array of rhenium based thermal detectors, a different option for the isotope is also being considered. The different option is 163Ho. The potential of using 187Re for a calorimetric neutrino mass experiment has been already demonstrated. On the contrary, no calorimetric spectrum of 163Ho has been so far measured with the precision required to set a useful limit on the neutrino mass. The first phase of the project (MARE-1) is a collection of activities with the aim of sorting out both the best isotope and the most suited detector technology to be used for the final experiment. One of the MARE-1 activities is carried out in Milan by the group of Milano–Bicocca in collaboration with NASA/GSFC and Wisconsin groups. The Milan MARE-1 arrays are based on semiconductor thermistors, provided by the NASA/GSFC group, with dielectric silver perrhenate absorbers, AgReO4. The experiment, which is presently being assembled, is designed to host up to 8 arrays. With 288 detectors, a sensitivity of 3 eV at 90% CL on the neutrino mass can be reached within 3 years. This contribution gives an outlook for the MARE activities for the active isotope selection. In this contribution the status and the perspectives of the MARE-1 in Milan are also reported