Recent years have witnessed many exciting breakthroughs in subnuclear and astroparticle physics. The detection of neutrino oscillations has proved that neutrino are massive particles and cosmological ...observations suggest that about 25% of the universe matter is dark and non-Baryonic. However, the neutrino mass scale needs still to be fixed and the non-Baryonic matter is still undetected with its real nature unknown. Cryogenic detectors can play a crucial role in addressing the still open questions, but a new generation of detectors is required. The present and future roles of cryogenic detectors in neutrino and astroparticle physics are discussed.
One of the major challenges in nowadays particle physics and astrophysics is the determination of the absolute neutrino mass scale. A powerful tool to evaluate the effective neutrino mass is the ...calorimetric measurement of the energy released in a nuclear decay involving neutrino. In order to reach a sensitivity on the neutrino mass of the order of 1 eV, not only detectors characterized by high performances (i.e. energy and time resolution of <inline-formula><tex-math notation="LaTeX">\sim</tex-math></inline-formula> eV at keV and <inline-formula><tex-math notation="LaTeX">\sim</tex-math></inline-formula>1 <inline-formula><tex-math notation="LaTeX">\mu</tex-math></inline-formula>s, respectively) are needed but also many detectors working in parallel are required. Microwave frequency readout provides an effective technique to read out large arrays of low temperature detectors allowing to reach a multiplex factor of the order of thousands. This technique is the one used to read out the 1000 Transition Edge Sensors of HOLMES, an experiment that aims at measuring the electron neutrino mass by means of the electron capture (EC) decay of <inline-formula><tex-math notation="LaTeX">^{163}</tex-math></inline-formula>Ho with an expected sensitivity of the order of 1 eV. In this contribution we present the characterization of the microwave-multiplexed readout system, and the results obtained with the detectors specifically designed for HOLMES.
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.
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 decreases abruptly because of the weakening of the electron–phonon coupling. A proper compromise between the value of critical temperature (and hence sensitivity to energy deposition) and readout power bearable by the device 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.
CUORE: a cryogenic underground observatory for rare events Arnaboldi, C; Avignone III, F.T; Beeman, J ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2004, Letnik:
518, Številka:
3
Journal Article
Recenzirano
Odprti dostop
CUORE is a proposed tightly packed array of 1000 TeO
2 bolometers, each being a cube
5
cm
on a side with a mass of
760
g
. The array consists of 25 vertical towers, arranged in a square of 5 towers×5 ...towers, each containing 10 layers of four crystals. The design of the detector is optimized for ultralow-background searches: for neutrinoless double-beta decay of
130
Te
(33.8% abundance), cold dark matter, solar axions, and rare nuclear decays. A preliminary experiment involving 20 crystals
3×3×6
cm
3
of
340
g
has been completed, and a single CUORE tower is being constructed as a smaller-scale experiment called CUORICINO. The expected performance and sensitivity, based on Monte Carlo simulations and extrapolations of present results, are reported.
Measuring the neutrino mass is one of the most compelling issues in particle physics. HOLMES is an experiment for a direct measurement of the neutrino mass. HOLMES will perform a precise measurement ...of the end point of the electron capture decay spectrum of
163
Ho
in order to extract information on the neutrino mass with a sensitivity as low as 1 eV. HOLMES, in its final configuration, will deploy a 1000-pixel array of low-temperature microcalorimeters: each calorimeter is made of an absorber, where the Ho atoms will be implanted, coupled to a transition-edge sensor (TES) thermometer. The detectors will be operated at the working temperature of
100
mK
provided by a dilution refrigerator. In order to read out the 1000-detector array of HOLMES, a multiplexing system is necessary: the choice is to couple the transition-edge sensors to a multiplexed rf-SQUID. In this contribution we outline the progress made towards the final configuration of HOLMES regarding both the performances of the TES detectors and the characteristics of the multiplexing system.
HOLMES is an experiment to directly measure the neutrino mass with a calorimetric approach. The calorimetric technique eliminates several systematic uncertainties usually present in spectrometers ...where the external source and decays to excited states affect the measurement. 163Ho is chosen as source for its very low Q value (2.8 keV), the proximity of the end-point to resonance M1 and its half life (4570 year). These features are optimal to reach simultaneously a reasonable activity to have sufficient statistics in the end-point and a small quantity of 163Ho embedded in the detector not to alter significantly its heat capacity. 163Ho will be produced via neutron irradiation of enriched 162Er2O3 at the Institute Laue–Langevin (Grenoble, France), and chemically separated at Paul Scherrer Institut (Villigen, Switzerland). It will arrive at INFN laboratory of Genova in oxide form (Ho2O3) with traces of others Ho isotopes and contaminants not removable using chemical methods. In particular, the metastable 166mHo undergoes beta decay with a half life of about 1200 year, if present 166mHo induces background below 5 keV. The removal of these contaminants is critical for HOLMES so a dedicated system is being set up. The system is designed to achieve an optimal mass separation for 163Ho and consists of two main components: an evaporation chamber and an ion implanter. In the evaporation chamber, holmium will be reduced in metallic form, using the reaction 2Y+Ho2O3→Y2O3+2Ho and used to produce a metallic target for the ion implanter source. The ion implanter consists of five main components: a Penning sputter ion source, an acceleration section, a magnetic/electrostatic mass analyser, a magnetic scanning stage and a focusing electrostatic triplet. In this contribution, we describe the procedures, under continuous refinement, for the holmium evaporation process, the ion-implanted metallic target production and the status of the ion implanter.
Status of the HOLMES Experiment Faverzani, M.; Alpert, B.; Balata, M. ...
Journal of low temperature physics,
05/2020, Letnik:
199, Številka:
3-4
Journal Article
Recenzirano
Odprti dostop
The absolute neutrino mass is still an unknown parameter in the modern landscape of particle physics. The HOLMES experiment aims at exploiting the calorimetric approach to directly measure the ...neutrino mass through the kinematic measurement of the decay products of the weak process decay of
163
Ho. This low energy decaying isotope, in fact, undergoes electron capture emitting a neutrino and leaving the daughter atom,
163
Dy
∗
, in an atomic excited state. This, in turn, relaxes by emitting electrons and, to a considerably lesser extent, photons. The high-energy portion of the calorimetric spectrum of this decay is affected by the non-vanishing neutrino mass value. Given the small fraction of events falling within the region of interest, to achieve a high experimental sensitivity on the neutrino mass, it is important to have a high activity combined with a very small undetected pileup contribution. To achieve these targets, the final configuration of HOLMES foresees the deployment of a large number of
163
Ho ion-implanted TESs characterized by an ambitiously high activity of 300 Hz each. In this paper, we outline the status of the major tasks that will bring HOLMES to achieve a statistical sensitivity on the neutrino mass as low as 2 eV/c
2
.
The CUORE Cryostat D’Addabbo, A.; Alduino, C.; Bersani, A. ...
Journal of low temperature physics,
12/2018, Letnik:
193, Številka:
5-6
Journal Article
Recenzirano
Odprti dostop
The Cryogenic Underground Observatory for Rare Events (CUORE) is a bolometric experiment for neutrinoless double-beta decay in
130
Te
search, currently taking data at the underground facility of ...Laboratori Nazionali del Gran Sasso (LNGS). The CUORE cryostat successfully cooled down a mass of about 1 ton at
∼
7
mK
, delivering a uniform and constant base temperature. This result marks a fundamental milestone in low-temperature detector techniques, opening the path for future ton-scale bolometric experiments searching for rare events. In this paper, we present the CUORE cryogenic infrastructure, briefly describing its critical subsystems.
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