18 research outputs found
Electron-phonon coupling in Ti/TiN MKIDs multilayer microresonator
Over the last few years there has been a growing interest toward the use of
superconducting microwave microresonators operated in quasi-thermal equilibrium
mode, especially applied to single particle detection. Indeed, previous devices
designed and tested by our group with X-ray sources in the keV range evidenced
that several issues arise from the attempt of detection through athermal
quasiparticles produced within direct strikes of X-rays in the superconductor
material of the resonator. In order to prevent issues related to quasiparticles
self-recombination and to avoid exchange of athermal phonons with the
substrate, our group focused on the development of thermal superconducting
microresonators. In this configuration resonators composed of multilayer films
of Ti/TiN sense the temperature of an absorbing material. To maximize the
thermal response, low critical temperature films are preferable. By lowering
the critical temperature, though, the maximum probing power bearable by the
resonators decrease abruptly because of the weakening of the electron-phonon
coupling. A proper compromise has to be found in order to avoid signal to noise
ratio degradation. In this contribution we report the latest measurement of the
electron-phonon coupling
Study of systematic effects in beta decay measurements with AgReO4 calorimeters
AgReO4 microcalorimeters are planned to be used again in the next generation
of calorimetric neutrino mass experiments with sensitivity down to 0.2 eV. The
understanding and characterization of all possible sources of systematic
uncertainties is crucial. In this work we focus on two of these sources, which
have been studied in the 10 detectors of the Milano AgReO4 array experiment
(MIBETA): a) the solid-state Beta Environmental Fine Structure (BEFS) observed
for the first time in AgReO4; b) the detector energy response for internal beta
events, which has been investigated with a dedicated measurement using a 44Ti
gamma source. The possible effects on neutrino mass experiments due to the
incomplete understanding of these two aspects are discussed.Comment: 3 pages, 2 figures Accepted, Nucl. Instr. Meth. Phys. A, proc. LTD11
Workshop, Tokyo, 200
High kinetic inductance NbTiN films for quantum limited travelling wave parametric amplifiers
A wide-bandwidth and low-noise amplification chain in the microwave regime is
crucial for the efficient read-out of quantum systems based on superconducting
detectors, such as Microwave Kinetic Inductance Detectors (MKIDs), Transition
Edge Sensors (TESs), Magnetic Microcalorimeters (MMCs), and RF cavities, as
well as qubits. Kinetic Inductance Travelling Wave Parametric Amplifiers
(KI-TWPAs) operated in a three-wave mixing fashion have demonstrated
exceptional dynamic range and low-noise performance, approaching the quantum
limit. These amplifiers can be fabricated using a single layer of a high
kinetic inductance film as weakly dispersive artificial transmission lines,
with the ability to control the phase-matched bandwidth through dispersion
engineering. In this study, we present the optimisation of the rf
sputter-deposition process of NbTiN films using a Nb80%T20 target, with the
goal of achieving precise control over film characteristics, resulting in high
kinetic inductance while maintaining a high transition temperature. The
parameter landscape related to the different sputtering conditions, such as
pressure, power, and nitrogen flow, has been explored and the film thickness
has been used as a fine-tuning parameter to adjust the properties of the final
NbTiN films used for the fabrication of KI-TWPAs. As a final result, we have
obtained a NbTiN film with a kinetic inductance of 8.5 pH/sq which we have
exploited to fabricate KI-TWPA prototype devices, showing promising
amplification performance
The commissioning of the CUORE experiment: the mini-tower run
CUORE is a ton-scale experiment approaching the data taking phase in Gran Sasso National Laboratory. Its primary goal is to search for the neutrinoless double-beta decay in 130Te using 988 crystals of tellurim dioxide. The crystals are operated as bolometers at about 10 mK taking advantage of one of the largest dilution cryostat ever built. Concluded in March 2016, the cryostat commissioning consisted in a sequence of cool down runs each one integrating new parts of the apparatus. The last run was performed with the fully configured cryostat and the thermal load at 4 K reached the impressive mass of about 14 tons. During that run the base temperature of 6.3 mK was reached and maintained for more than 70 days. An array of 8 crystals, called mini-tower, was used to check bolometers operation, readout electronics and DAQ. Results will be presented in terms of cooling power, electronic noise, energy resolution and preliminary background measurements
Results from the Cuore Experiment
The Cryogenic Underground Observatory for Rare Events (CUORE) is the first bolometric experiment searching for neutrinoless double beta decay that has been able to reach the 1-ton scale. The detector consists of an array of 988 TeO2 crystals arranged in a cylindrical compact structure of 19 towers, each of them made of 52 crystals. The construction of the experiment was completed in August 2016 and the data taking started in spring 2017 after a period of commissioning and tests. In this work we present the neutrinoless double beta decay results of CUORE from examining a total TeO2 exposure of 86.3kg yr, characterized by an effective energy resolution of 7.7 keV FWHM and a background in the region of interest of 0.014 counts/ (keV kg yr). In this physics run, CUORE placed a lower limit on the decay half- life of neutrinoless double beta decay of 130Te > 1.3.1025 yr (90% C. L.). Moreover, an analysis of the background of the experiment is presented as well as the measurement of the 130Te 2vo3p decay with a resulting half- life of T2 2. [7.9 :- 0.1 (stat.) :- 0.2 (syst.)] x 10(20) yr which is the most precise measurement of the half- life and compatible with previous results
The matrix optimum filter for low temperature detectors dead-time reduction
Experiments aiming at high sensitivities usually demand for a very high statistics in order to reach more precise measurements. However, for those exploiting Low Temperature Detectors (LTDs), a high source activity may represent a drawback, if the events rate becomes comparable with the detector characteristic temporal response. Indeed, since commonly used optimum filtering approaches can only process LTDs signals well isolated in time, a non-negligible part of the recorded experimental data-set is discarded and hence constitute the dead-time. In the presented study we demonstrate that, thanks to the matrix optimum filtering approach, the dead-time of an experiment exploiting LTDs can be strongly reduced
The cryostat of the CUORE Project, a 1-ton scale cryogenic experiment for Neutrinoless Double Beta Decay Research
High kinetic inductance NbTiN films for quantum limited travelling wave parametric amplifiers
A wide-bandwidth and low-noise amplification chain in the microwave regime is crucial for the efficient read-out of quantum systems based on superconducting detectors, such as Microwave Kinetic Inductance Detectors (MKIDs), Transition Edge Sensors (TESs), Magnetic Microcalorimeters (MMCs), and RF cavities, as well as qubits. Kinetic Inductance Travelling Wave Parametric Amplifiers (KI-TWPAs) operated in a three-wave mixing fashion have demonstrated exceptional dynamic range and low-noise performance, approaching the quantum limit. These amplifiers can be fabricated using a single layer of a high kinetic inductance film as weakly dispersive artificial transmission lines, with the ability to control the phase-matched bandwidth through dispersion engineering. In this study, we present the optimisation of the rf sputter-deposition process of NbTiN films using a Nb80%Ti20% target, with the goal of achieving precise control over film characteristics, resulting in high kinetic inductance while maintaining a high transition temperature. The parameter landscape related to the different sputtering conditions, such as pressure, power, and nitrogen flow, has been explored and the film thickness has been used as a fine-tuning parameter to adjust the properties of the final NbTiN films used for the fabrication of KI-TWPAs. As a final result, we have obtained a NbTiN film with a kinetic inductance of 8.5 pH/sq which we have exploited to fabricate KI-TWPA prototype devices, showing promising amplification performance
Cross-analysis of two randomized controlled trials to compare pure versus robot-assisted laparoscopic approach during off-clamp partial nephrectomy
N.A