487 research outputs found
Characterization of high impedance connecting links for Bolometric detectors
Abstract High impedance connecting links and cables are tested at low frequency in terms of their parasitic impedance to ground and to neighboring connecting links. These parameters must be well characterized with detectors operated at low temperature, especially when the very front-end is at room temperature, which results in a long link. This is the case of the LUCIFER experiment, an array of crystals where every event of interest produces two signals, one composed of phonons, the other of photons. The parasitic impedance is usually considered to be the parallel combination of a resistance and a capacitance. We characterized both and found that from the static measurements the capacitance of the cable resulted much larger. On the basis of this result we optimized the measurement set-up and developed a model to account for this behavior
Characterization of the Hamamatsu R11265-103-M64 multi-anode photomultiplier tube
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.Comment: 22 page
An ultra fast, low power readout chain for single photon sensitivity with multi-anode photomultiplier tubes for the RICH upgrade at LHCb
Abstract An upgrade proposal for the LHCb RICH detectors at the Large Hadron Collider at CERN is being developed at the INFN section of Milano Bicocca, based on multi-anode photomultiplier tubes. The application requires the fast readout of Cherenkov rings of photons, with single photon sensitivity, at an event rate up to 40 MHz. The proposed readout chain is tailored for the R7600 multi-anode photomultiplier tubes from Hamamatsu, which proved to fit the single photon sensitivity requirement. The readout electronics for each pixel will be composed of an analog pulse shaper, a binary discriminator and additional digital circuitry to count the pulses. A prototype of the analog shaper was built with commercial discrete transistors in Silicon–Germanium (SiGe) Heterojunction technology. The tradeoff between response speed and power dissipation was investigated; and power as low as a few mW per channel could be achieved with response times of the order of one nanosecond. Furthermore, noise and jitter were evaluated, showing very good performances of the prototype
Electrical characterization of the low background Cu-PEN links of the CUORE experiment
Abstract In the CUORE experiment, under construction at LNGS (Gran Sasso National Laboratory), Cu-PEN tapes are the first part of the connecting links between the detector and the front-end electronics. Deep electrical characterization on each tape is to be performed, to ascertain that they comply with the requirements of the experiment. The characterization method is presented here. The first part is based on the time domain reflectometry (TDR) technique, to check the integrity of the electrical link while touching only one end of the tape, to avoid any possible damage to the bonding pads. The TDR measurement allows to locate possible defects on the tapes with a resolution of about 5 cm. The second part of the characterization is focused on the parasitic impedance between neighboring links. For this characterization, a commercial electrometer is used; custom boards with remote control capability were built, in order to be able to check the links in vacuum and reach sensitivities on the parasitic conductance of the order of 1 pA/V
Critical Temperature tuning of Ti/TiN multilayer films suitable for low temperature detectors
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 , 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 around
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 K temperature
range properly choosing the Ti thickness in the nm range, and the
TiN thickness in the nm rang
Development of microwave superconducting microresonators for neutrino mass measurement in the HOLMES framework
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 163Ho. 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 Microwave Kinetic Inductance Detectors (MKIDs), 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 163Ho. 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 . We developed Ti/TiN
multilayer microresonators with 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
First characterization of the Hamamatsu R11265 multi-anode photomultiplier tube
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
The Readout and Biasing System for the MARE Experiment in Milan
The complete readout and biasing system for the MARE experiment in Milan is presented. The experiment aims at a direct measurement of the neutrino mass, and is based on an array of microcalorimeters coupled to semiconductor thermistors. The readout is based on JFETs operated inside the cryostat at cold (130 K), to buffer the voltage signal from the thermistors. The sources of the JFETs are fed into second stage amplifiers with very low noise (less than white noise) and programmable high gain. The outputs are then processed by Bessel filters and acquired with a commercial DAQ system. Every 20 channels, an additional group of 4 is used to amplify the ground reference from inside the cryostat; this common ground signal is then subtracted from each channel. This approach allows to recover a fully differential readout with a smaller number of cables with respect to the standard differential configuration. The detector bias is programmable in voltage and sign with 8-bit resolution. A test signal can be superimposed on the bias voltage, in order to test each channel individually. All the readout system is remotely programmable from a PC, coupled through optical fibers
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