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Search Results: 1 - 10 of 461785 matches for " A. Giachero "
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A new approach to the front-end readout of cryogenic ionization detectors
C. Cattadori,B. Gallese,A. Giachero,C. Gotti,M. Maino,G. Pessina
Physics , 2011, DOI: 10.1088/1748-0221/6/05/P05006
Abstract: We present a novel approach to the readout of ionization detectors. The solution allows to minimize the number of components and the space occupation close to the detector. This way a minimal impact is added on the radioactive background in those experiments where very low signal rates are expected, such as GERDA and MAJORANA. The circuit consists in a JFET transistor and a remote second stage. The DC feedback path is closed using a diode. Two signal cables are only necessary for biasing and readout.
GeFRO: a New Charge Sensitive Amplifier Design with a Minimal Number of Front-end Components
L. Cassina,C. Cattadori,A. Giachero,C. Gotti,M. Maino,G. Pessina
Physics , 2013,
Abstract: A new approach was developed for the design of front-end circuits for semiconductor radiation detectors. The readout scheme consists of a first stage made of only a few components located close to the detector, and of a remote second stage located far from the detector, several meters away. The second stage amplifies the signals from the first stage and closes the feedback loop to discharge the input node after each event. The circuit has two outputs: one gives a "fast" signal, with a bandwidth larger than 20 MHz, allowing to preserve the high frequency components of the detector signals, which may be useful for timing measurements, pile-up rejection or pulse shape discrimination. The second output gives a "slow" signal, whose gain depends only on the value of the feedback capacitor, as happens with a classic charge sensitive amplifier, allowing to obtain higher resolution and lower drift. The prototype was named GeFRO for Germanium front-end, and was tested with a BEGe detector from Canberra. The wide bandwidth of the "fast" signal gave a timing resolution of the order of 20 ns. The noise of the circuit at the "slow" output after a 10 us Gaussian shaping was close to 160 electrons RMS with an input capacitance of 26 pF.
Characterization of the Hamamatsu R11265-103-M64 multi-anode photomultiplier tube
L. Cadamuro,M. Calvi,L. Cassina,A. Giachero,C. Gotti,B. Khanji,M. Maino,C. Matteuzzi,G. Pessina
Physics , 2014, DOI: 10.1088/1748-0221/9/06/P06021
Abstract: The aim of this paper is to fully characterize the new multi-anode photomultiplier tube R11265-103-M64, produced by Hamamatsu. Its high effective active area (77%), its pixel size, the low dark signal rate and the capability to detect single photon signals make this tube suitable for an application in high energy physics, such as for RICH detectors. Four tubes and two different bias voltage dividers have been tested. The results of a standard characterization of the gain and the anode uniformity, the dark signal rate, the cross-talk and the device behaviour as a function of temperature have been studied. The behaviour of the tube is studied in a longitudinal magnetic field up to 100 Gauss. Shields made of a high permeability material are also investigated. The deterioration of the device performance due to long time operation at intense light exposure is studied. A quantitative analysis of the variation of the gain and the dark signals rate due to the aging is described.
Algorithms for Identification of Nearly-Coincident Events in Calorimetric Sensors
B. Alpert,E. Ferri,D. Bennett,M. Faverzani,J. Fowler,A. Giachero,J. Hays-Wehle,M. Maino,A. Nucciotti,A. Puiu,D. Swetz,J. Ullom
Physics , 2015,
Abstract: For experiments with high arrival rates, reliable identification of nearly-coincident events can be crucial. For calorimetric measurements to directly measure the neutrino mass such as HOLMES, unidentified pulse pile-ups are expected to be a leading source of experimental error. Although Wiener filtering can be used to recognize pile-up, it suffers errors due to pulse-shape variation from detector nonlinearity, readout dependence on sub-sample arrival times, and stability issues from the ill-posed deconvolution problem of recovering Dirac delta-functions from smooth data. Due to these factors, we have developed a processing method that exploits singular value decomposition to (1) separate single-pulse records from piled-up records in training data and (2) construct a model of single-pulse records that accounts for varying pulse shape with amplitude, arrival time, and baseline level, suitable for detecting nearly-coincident events. We show that the resulting processing advances can reduce the required performance specifications of the detectors and readout system or, equivalently, enable larger sensor arrays and better constraints on the neutrino mass.
Development of microwave superconducting microresonators for neutrino mass measurement in the HOLMES framework
A. Giachero,P. K. Day,P. Falferi,M. Faverzani,E. Ferri,C. Giordano,M. Maino,B. Margesin,R. Mezzena,R. Nizzolo,A. Nucciotti,A. Puiu,L. Zanetti
Physics , 2015,
Abstract: The European Research Council has recently funded HOLMES, a project with the aim of performing a calorimetric measurement of the electron neutrino mass measuring the energy released in the electron capture decay of \textsuperscript{163}Ho. The baseline for HOLMES are microcalorimeters coupled to Transition Edge Sensors (TESs) read out with rf-SQUIDs, for microwave multiplexing purposes. A promising alternative solution is based on superconducting microwave resonators, that have undergone rapid development in the last decade. These detectors, called MKIDs (Microwave Kinetic Inductance Detectors), are inherently multiplexed in the frequency domain and suitable for even larger-scale pixel arrays, with theoretical high energy resolution and fast response. The aim of our activity is to develop arrays of microresonator detectors for X-ray spectroscopy and suitable for the calorimetric measurement of the energy spectra of \textsuperscript{163}Ho. Superconductive multilayer films composed by a sequence of pure Titanium and stoichiometric TiN layers show many ideal properties for MKIDs, such as low loss, large sheet resistance, large kinetic inductance, and tunable critical temperature $T_c$. We developed Ti/TiN multilayer microresonators with $T_c$ within the range from 70\,mK to 4.5\,K and with good uniformity. In this contribution we present the design solutions adopted, the fabrication processes and the characterization results.
Critical Temperature tuning of Ti/TiN multilayer films suitable for low temperature detectors
A. Giachero,P. Day,P. Falferi,M. Faverzani,E. Ferri,C. Giordano,B. Marghesin,F. Mattedi,R. Mezzena,R. Nizzolo,A. Nucciotti
Physics , 2013, DOI: 10.1007/s10909-013-1078-0
Abstract: We present our current progress on the design and test of Ti/TiN Multilayer for use in Kinetic Inductance Detectors (KIDs). Sensors based on sub-stoichiometric TiN film are commonly used in several applications. However, it is difficult to control the targeted critical temperature $T_C$, to maintain precise control of the nitrogen incorporation process and to obtain a production uniformity. To avoid these problems we investigated multilayer Ti/TiN films that show a high uniformity coupled with high quality factor, kinetic inductance and inertness of TiN. These features are ideal to realize superconductive microresonator detectors for astronomical instruments application but also for the field of neutrino physics. Using pure Ti and stoichiometric TiN, we developed and tested different multilayer configuration, in term of number of Ti/TiN layers and in term of different interlayer thicknesses. The target was to reach a critical temperature $T_C$ around $(1\div 1.5)$ K in order to have a low energy gap and slower recombination time (i.e. low generation-recombination noise). The results prove that the superconductive transition can be tuned in the $(0.5\div 4.6)$ K temperature range properly choosing the Ti thickness in the $(0\div 15)$ nm range, and the TiN thickness in the $(5\div 100)$ nm range
Modeling high impedance connecting links and cables below 1 Hz
Andrea Giachero,Claudio Gotti,Matteo Maino,Gianluigi Pessina
Physics , 2012, DOI: 10.1088/1748-0221/7/08/P08004
Abstract: High impedance connecting links and cables are modeled at low frequency in terms of their impedance to ground and to neigbouring connecting links. The impedance is usually considered to be the parallel combination of a resistance and a capacitance. While this model is adequate at moderate and low frequency, it proved to be not satisfactory at very low frequency, in the fractions of Hz range. Deep characterization was carried out on some samples down to 10 uHz, showing that an additional contribution to capacitance can emerge. A model was developed to explain and account for this additional contribution.
Searches for axioelectric effect of solar axions with BGO-scintillator and BGO-bolometer detectors
V. N. Muratova,A. V. Derbin,L. Gironi,S. S Nagorny,L. Pattavina,S. V. Bakhlanov,J. W. Beeman,F. Bellini,M. Biassoni,S. Capelli,M. Clemenza,I. S. Dratchnev,E. Ferri,A. Giachero,C. Gotti,A. S. Kayunov,C. Maiano,M. Maino,M. Pavan,S. Pirro,D. A. Semenov,M. Sisti,E. V. Unzhakov
Physics , 2015,
Abstract: A search for axioelectric absorption of 5.5 MeV solar axions produced in the $p + d \rightarrow {^3\rm{He}}+\gamma~(5.5~ \rm{MeV})$ reaction has been performed with a BGO detectors. A model-independent limit on the product of axion-nucleon $g_{AN}^3$ and axion-electron $g_{Ae}$ coupling constants has been obtained: $| g_{Ae}\times g_{AN}^3|< 1.9\times 10^{-10}$ for 90\% C.L..
Search for axioelectric effect of solar axions using BGO scintillating bolometer
A. V. Derbin,L. Gironi,S. S. Nagorny,L. Pattavina,J. W. Beeman,F. Bellini,M. Biassoni,S. Capelli,M. Clemenza,I. S. Drachnev,E. Ferri,A. Giachero,C. Gotti,A. S. Kayunov,C. Maiano,M. Maino,V. N. Muratova,M. Pavan,S. Pirro,M. Sisti,D. A. Semenov,E. V. Unzhakov
Physics , 2014, DOI: 10.1140/epjc/s10052-014-3035-8
Abstract: A search for axioelectric absorption of solar axions produced in the $ p + d \rightarrow {^3\rm{He}}+\gamma~(5.5~ \rm{MeV})$ reactions has been performed with a BGO detector placed in a low-background setup. A model-independent limit on an axion-nucleon and axion-electron coupling constant has been obtained: $| g_{Ae}\times g_{AN}^3|< 1.9\times 10^{-10}$ for 90% confidence level. The constrains of the axion-electron coupling have been obtained for hadronic axion with masses in (0.1 - 1) MeV range: $|g_{Ae}| \leq (0.96 - 8.2)\times 10^{-8}$.
Large area Si low-temperature light detectors with Neganov-Luke effect
M. Biassoni,C. Brofferio,S. Capelli,L. Cassina,M. Clemenza,O. Cremonesi,M. Faverzani,E. Ferri,A. Giachero,L. Gironi,C. Giordano,C. Gotti,M. Maino,B. Margesin,A. Nucciotti,M. Pavan,G. Pessina,E. Previtali,A. Puiu,M. Sisti,F. Terranova
Physics , 2015,
Abstract: Next generation calorimetric experiments for the search of rare events rely on the detection of tiny amounts of light (of the order of 20 optical photons) to discriminate and reduce background sources and improve sensitivity. Calorimetric detectors are the simplest solution for photon detection at cryogenic (mK) temperatures. The development of silicon based light detectors with enhanced performance thanks to the use of the Neganov-Luke effect is described. The aim of this research line is the production of high performance detectors with industrial-grade reproducibility and reliability.
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