Status of the HOLMES Experiment De Gerone, M.; Alpert, B.; Balata, M. ...
Journal of low temperature physics,
12/2022, Letnik:
209, Številka:
5-6
Journal Article
Recenzirano
Odprti dostop
The assessment of the absolute
ν
mass scale is a crucial challenge in today’s particle physics and cosmology. The only experimental method which can provide a model-independent measurement is the ...investigation of endpoint distortion in beta/electron capture spectra.
163
Ho is a good choice thanks to its low electron capture Q value (about 2.8 keV), the proximity of the end-point to resonance M1 and its half-life (4570 years). The HOLMES experiment will exploit a calorimetric measurement of
163
Ho decay spectrum deploying a large set of cryogenic micro-calorimeters containing implanted
163
Ho. In order to get the best experimental sensitivity, it is crucial to combine high activity with very small undetected pileup contribution. Therefore, the main tasks of the experiment consist of: the development of about 1000 fast (3
μ
s time resolution) cryogenic micro-calorimeters characterized by extraordinary energy resolution (down to few eV); the embedding of
163
Ho source inside the calorimeters, avoiding to spoil detectors’ thermodynamical properties (mainly heat capacity) and preventing pileup issues. Moreover, it is also necessary to avoid contamination from other radionuclides, mainly
166
m
Ho. Finally, an efficient high-bandwidth multiplexed readout has to be developed. The commissioning of the first implanted array is currently ongoing; the first data acquisition is expected to start in fall 2022. Here, the status of the experiment and the first results of detector commissioning will be discussed.
Thermal detectors are a powerful instrument for the search of rare particle physics events. Inorganic crystals are classically used as thermal detectors held in supporting frames made of copper. In ...this work, a novel approach to the operation of thermal detectors is presented, where TeO
2
crystals are cooled down to
∼
10 mK in a light structure built with plastic materials. The advantages of this approach are discussed.
Transition-Edge Sensors for HOLMES Puiu, A.; Becker, D.; Bennett, D. ...
Journal of low temperature physics,
05/2020, Letnik:
199, Številka:
3-4
Journal Article
Recenzirano
HOLMES is an experiment aiming at performing a direct measurement of the neutrino mass from the electron capture (EC) spectrum of
163
Ho
. In order to reach a sensitivity of the order of
∼
1 eV/c
2
...on the neutrino mass, it is necessary to gather as many as
10
13
events in the 3-year projected live time of HOLMES, keeping the pileup fraction as low as
10
-
4
. This is not a trivial matter when it comes to low- temperature calorimeters, which usually have a rather slow time response. At the same time, a large number of detectors need to be operated simultaneously, and hence, in order to avoid an extremely large cryogenic facility, multiplexing is required. In this contribution, I will outline the current status and perspective of HOLMES, with special care devoted to the detectors and readout system, which have currently reached their target performance.
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.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We report on the development of thermal kinetic inductance detectors (TKIDs) suitable to perform X-ray spectroscopy measurements. The aim is to implement MKIDs sensors working in thermal ...quasi-equilibrium mode to detect X-ray photons as pure calorimeters. The thermal mode is a variation on the MKID classical way of operation that has generated interest in recent years. TKIDs can offer the MKIDs inherent multiplexibility in the frequency domain, a high spatial resolution comparable with CCDs, and an energy resolution theoretically limited only by thermodynamic fluctuations across the thermal weak links. Microresonators are built in Ti/TiN multilayer technology with the inductive part thermally coupled with a metal absorber on a suspended SiN membrane, to avoid escape of phonons from the film to the substrate. The mid-term goal is to optimize the single-pixel design in terms of superconducting critical temperatures, internal quality factors, kinetic inductance and spectral energy resolution. The final goal is to realize a demonstrator array for a next generation thousand pixels X-ray spectrometer. In this contribution, the status of the project after one year of developments is reported, with detailed reference to the microresonators design and simulations and to the fabrication process.
The determination of the neutrino mass is an open issue in modern particle physics and astrophysics. The direct mass measurement is the only theory-unrelated experimental tool capable to probe such ...quantity. The HOLMES experiment aims to measure the end-point energy of the electron capture (EC) decay of 163Ho with a statistical sensitivity on the neutrino mass as low as ∼1 eV/c2. In order to acquire the large needed statistics, by keeping the pile-up contribution as low as possible, 1024 transition edge sensors (TESs) with high energy and time resolutions will be employed. Microcalorimeter and bolometer arrays based on transition edge sensor with thousands of pixels are under development for several space-based and ground-based applications, including astrophysics, nuclear and particle physics, and materials science. The common necessary challenge is to develop pratical multiplexing techniques in order to simplify the cryogenics and readout systems. Despite the various multiplexing variants which are being developed have been successful, new approaches are needed to enable scaling to larger pixel counts and faster sensors, as requested for HOLMES, reducing also the cost and complexity of readout. A very novel technique that meets all of these requirements is based on superconducting microwave resonators coupled to radio-frequency Superconducting Quantum Interference Devices, in which the changes in the TES input current is tranduced to a change in phase of a microwave signal. In this work we introduce the basics of this technique, the design and development of the first two-channel read out system and its performances with the first TES detectors specifically designed for HOLMES. In the last part we explain how to extend this approach scaling to 1024 pixels.
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.
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.
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
.
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