180
m
Ta
is the longest-lived metastable state presently known. Its decay has not been observed yet. In this work, we report a new result on the decay of
180
m
Ta
obtained with a 2015.12-g tantalum ...sample measured for 527.7 d with an ultra-low background HPGe detector in the STELLA laboratory of the Laboratori Nazionali del Gran Sasso (LNGS), in Italy. Before the measurement, the sample has been stored deep-underground for ten years, resulting in subdominant background contributions from cosmogenically activated
182
Ta
. We observe no signal in the regions of interest and set half-life limits on the process for the two channels EC and
β
-
:
T
1
/
2
,
EC
>
1.6
×
10
18
year and
T
1
/
2
,
β
-
>
1.1
×
10
18
year (90% C. I.), respectively. We also set the limit on the
γ
de-excitation / IC channel:
T
1
/
2
,
IC
>
4.1
×
10
15
year (90% C. I.). These are, as of now, the most stringent bounds on the decay of
180
m
Ta
worldwide. Finally, we test the hypothetical scenarios of de-excitation of
180
m
Ta
by cosmological Dark Matter and constrain new parameter space for strongly-interacting dark-matter particle with mass up to
10
5
GeV.
Next-generation experiments searching for rare events must satisfy increasingly stringent requirements on the bulk and surface radioactive contamination of their active and structural materials. The ...measurement of surface contamination is particularly challenging, as no existing technology is capable of separately measuring parts of the 232Th and 238U decay chains that are commonly found to be out of secular equilibrium. We will present the results obtained with a detector prototype consisting of 8 silicon wafers of 150 mm diameter instrumented as bolometers and operated in a low-background dilution refrigerator at the Gran Sasso Underground Laboratory of INFN, Italy. The prototype was characterized by a baseline energy resolution of few keV and a background <100 nBq/cm2 in the full range of α energies, obtained with simple procedures for cleaning of all employed materials and no specific measures to prevent recontamination. Such performance, together with the modularity of the detector design, demonstrate the possibility to realize an alpha detector capable of separately measuring all alpha emitters of the 232Th and 238U chains, possibly reaching a sensitivity of few nBq/cm2.
•Material screening.•Bolometric alpha detector.•Low-radioactivity measurements.
We present the application of a simplified thermal model for the description of the response function of low-temperature calorimeters consisting of
TeO
2
crystals read-out by NTD thermistors operated ...at temperatures
T
∼
10
mK. Relying on both the analysis of the NTD load curves (from which we measured the main thermal conductances of the system) (Biassoni et al. in J Low Temp Phys 206:80–96, 2022) and on the analysis of the shape of thermal pulses acquired at different temperatures, we identified and quantified the physical parameters that determine the characteristic time constants of the pulses. In particular, we identified three different contributions to the heat capacity of the detector: the crystal phonon system (scaling as
T
3
), the NTD electron system (scaling as
T
) and a term related to the metalization process of the NTD electrodes (scaling as
T
-
2
).
Core-collapse Supernovae (SNe) are one of the most energetic events in the Universe, during which almost all the star's binding energy is released in the form of neutrinos. These particles are direct ...probes of the processes occurring in the stellar core and provide unique insights into the gravitational collapse. RES-NOVA will revolutionize how we detect neutrinos from astrophysical sources, by deploying the first ton-scale array of cryogenic detectors made from archaeological lead. Pb offers the highest neutrino interaction cross-section via coherent elastic neutrino-nucleus scattering (CEνNS). Such process will enable RES-NOVA to be equally sensitive to all neutrino flavours. For the first time, we propose the use archaeological Pb as sensitive target material in order to achieve an ultra-low background level in the region of interest (O(1 keV)). All these features make possible the deployment of the first cm-scale neutrino telescope for the investigation of astrophysical sources. In this contribution, we will characterize the radiopurity level and the performance of a small-scale proof-of-principle detector of RES-NOVA, consisting in a PbWO
crystal made from archaeological-Pb operated as cryogenic detector.
The ACCESS (Array of Cryogenic Calorimeters to Evaluate Spectral Shapes) project aims to establish a novel technique to perform precision measurements of forbidden
β
-decays, which can serve as an ...important benchmark for nuclear physics calculations and represent a significant background in astroparticle physics experiments. ACCESS will operate a pilot array of cryogenic calorimeters based on natural and doped crystals containing
β
-emitting radionuclides. In this way, natural (e.g.
113
Cd and
115
In) and synthetic isotopes (e.g.
99
Tc) will be simultaneously measured with a common experimental technique. The array will also include further crystals optimised to disentangle the different background sources, thus reducing the systematic uncertainty. In this paper, we give an overview of the ACCESS research program, discussing a detector design study and promising results of
115
In.
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.
•Cancer care planning and delivery must take a comprehensive, nationwide approach to guarantee access to innovation.•Digital, community and primary care delivery during the pandemic showed promise in ...complementing hospital-based care.•Leveraging health data analysis and full activation of cancer networks can improve care coordination and address inequalities.
Policymakers everywhere struggle to introduce therapeutic innovation while controlling costs, a particular challenge for the universal Italian National Healthcare System (SSN), which spends only 8.8% of GDP to care for one of the world’s oldest populations. Oncology provides a telling example, where innovation has dramatically improved care and survival, transforming cancer into a chronic condition. However, innovation has also increased therapy duration, adverse event management, and service demand. The SSN risks collapse unless centralized cancer planning changes gear, particularly with Covid-19 causing treatment delays, worsening patient prognosis and straining capacity. In view of the 750 billion Euro “Next Generation EU”, released by the European Union to relieve Member States hit by the pandemic, the SSN tapped a multidisciplinary research team to identify key strategies for equitable uptake of innovations in treatment and delivery, with emphasis on data-driven technological and managerial advancements – and lessons from Covid-19.
Abstract $$^{180\textrm{m}}\text {Ta}$$ 180 m Ta is the longest-lived metastable state presently known. Its decay has not been observed yet. In this work, we report a new result on the decay of ...$$^{180\textrm{m}}\text {Ta}$$ 180 m Ta obtained with a 2015.12-g tantalum sample measured for 527.7 d with an ultra-low background HPGe detector in the STELLA laboratory of the Laboratori Nazionali del Gran Sasso (LNGS), in Italy. Before the measurement, the sample has been stored deep-underground for ten years, resulting in subdominant background contributions from cosmogenically activated $$^{182}\text {Ta}$$ 182 Ta . We observe no signal in the regions of interest and set half-life limits on the process for the two channels EC and $$\beta ^-$$ β - : $$T_{1/2,~\textrm{EC}}> 1.6 \times 10^{18}$$ T 1 / 2 , EC > 1.6 × 10 18 year and $$T_{1/2,~\beta ^-}> 1.1\times 10^{18}$$ T 1 / 2 , β - > 1.1 × 10 18 year (90% C. I.), respectively. We also set the limit on the $$\gamma $$ γ de-excitation / IC channel: $$T_{1/2,~\textrm{IC}}> 4.1 \times 10^{15}$$ T 1 / 2 , IC > 4.1 × 10 15 year (90% C. I.). These are, as of now, the most stringent bounds on the decay of $$^{180\textrm{m}}\text {Ta}$$ 180 m Ta worldwide. Finally, we test the hypothetical scenarios of de-excitation of $$^{180\textrm{m}}\text {Ta}$$ 180 m Ta by cosmological Dark Matter and constrain new parameter space for strongly-interacting dark-matter particle with mass up to $$10^5$$ 10 5 GeV.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
PDF
