No Arabic abstract
The possibility to use a mini-phoswich detector to identify ions in the region of Z ~ 10 is explored in the framework of the NUMEN project. The NUMEN program, aimed at the investigation of the nuclear matrix elements connected to the neutrinoless double beta decay by means of double charge exchange nuclear reactions, foresees very high fluencies, which prevent the use of standard silicon as stop detectors. The need of reasonable radiation hardness, together with a total energy resolution around 2% and a high granularity, makes scintillators possible candidates. Promising results are obtained using an array of plastic + inorganic phoswich scintillators readout by means of Silicon Photo Multipliers.
We have studied neutron response of PARIS phoswich [LaBr$_3$(Ce)-NaI(Tl)] detector which is being developed for measuring the high energy (E$_{gamma}$ = 5 - 30 MeV) $gamma$ rays emitted from the decay of highly collective states in atomic nuclei. The relative neutron detection efficiency of LaBr$_3$(Ce) and NaI(Tl) crystal of the phoswich detector has been measured using the time-of-flight (TOF) and pulse shape discrimination (PSD) technique in the energy range of E$_n$ = 1 - 9 MeV and compared with the GEANT4 based simulations. It has been found that for E$_n$ $>$ 3 MeV, $sim$ 95 % of neutrons have the primary interaction in the LaBr$_3$(Ce) crystal, indicating that a clear n-$gamma$ separation can be achieved even at $sim$15 cm flight path.
A prototype of a position sensitive photo-detector with 5.6 x 5.6 cm2 detection area readout with 64 Hamamatsu MPPCs (S10931-100P) with 3 x 3 mm2 active area each has been built and tested. The photo-sensors are arranged in a 8 x 8 array with a quadratic mirror light guide on top. The module is currently readout by in-house developed preamplifier boards but employing existing ASIC chips optimized for SiPM readout is also planned. Such a device is one of the candidates to be used for photon detection in the PANDA DIRC detectors.
In this paper we report on the characterization of SiPM tiles developed for the R & D on the DUNE Photon Detection System. The tiles were produced by Fondazione Bruno Kessler (FBK) employing NUV-HD-SF SiPMs. Special emphasis is given on cryo-reliability of the sensors, i.e. the stability of electric and mechanical properties after thermal cycles at room and 77K temperature. The characterization includes the determination of the I-V curve, a high sensitivity measurement of Dark Count Rate at different overvoltages, and correlated noise. The single p.e. sensitivity is measured as a function of the number of sensors connected to a single electronic channel, after amplification at 77K using a dedicated cold amplifier.
The european Fazia collaboration aims at building a new modular array for charged product identification to be employed for heavy-ion studies. The elementary module of the array is a Silicon-Silicon-CsI telescope, optimized for ion identification also via pulse shape analysis. The achievement of top performances imposes specific electronics which has been developed by FAZIA and features high quality charge and current preamplifiers, coupled to fully digital front-end. During the initial R&D phase, original and novel solutions have been tested in prototypes, obtaining unprecedented ion identification capabilities. FAZIA is now constructing a demonstrator array consisting of about two hundreds telescopes arranged in a compact and transportable configuration. In this contribution, we mainly summarize some aspects studied by FAZIA to improve the ion identification. Then we will briefly discuss the FAZIA program centered on experiments to be done with the demonstrator. First results on the isospin dynamics obtained with a reduced set-up demonstrate well the performance of the telescope and represent a good starting point towards future investigations with both stable and exotic beams.
An upgraded GARFIELD + Ring Counter (RCo) apparatus is presented with improved performances as far as electronics and detectors are concerned. On one side fast sampling digital read out has been extended to all detectors, allowing for an important simplification of the signal processing chain together with an enriched extracted information. On the other side a relevant improvement has been made in the forward part of the setup (RCo): an increased granularity of the CsI(Tl) crystals and a higher homogeneity in the silicon detector resistivity. The renewed performances of the GARFIELD + RCo array make it suitable for nuclear reaction measurements both with stable and with Radioactive Ion Beams (RIB), like the ones foreseen for the SPES facility, where the Physics of Isospin can be studied.