A
bstract
The European Spallation Source (ESS), presently well on its way to completion, will soon provide the most intense neutron beams for multi-disciplinary science. Fortuitously, it will also ...generate the largest pulsed neutrino flux suitable for the detection of Coherent Elastic Neutrino-Nucleus Scattering (CE
ν
NS), a process recently measured for the first time at ORNL’s Spallation Neutron Source. We describe innovative detector technologies maximally able to profit from the order-of-magnitude increase in neutrino flux provided by the ESS, along with their sensitivity to a rich particle physics phenomenology accessible through high-statistics, precision CE
ν
NS measurements.
Design of Diagonalised Square-Base Bistable Modules Freire-Tellado, M J; Muñoz-Vidal, M; Pérez-Valcárcel, J
The Arabian Journal for Science and Engineering. Section B, Engineering,
04/2024, Letnik:
49, Številka:
4
Journal Article
Recenzirano
The use of diagonalised modules is one of the techniques for converting a deployable structure into a bistable one. The layout of these modules is complicated by the fact that the geometric ...incompatibility must be sufficient in the service phase of the structure without structural failure during deployment. The text attempts to facilitate this harmonisation work. The folding process of both cuboid and pyramidal frustum diagonalised modules is analysed, and the different situations that occur are established. The geometric incompatibilities of the different modules proposed and of some variants and their evolution during the folding process are studied. A mechanical analysis is carried out based on dynamic calculations of the bending process of the different models studied. A set of graphs are obtained which reflect the evolution of the internal forces (axial forces and bending moments) of the different elements of the module throughout the process, as well as the elastic energy of the module, which are contrasted with those obtained geometrically and with several kinematic models carried out. The text identifies a range of recommended geometric incompatibilities and provides a control method for the design of pyramidal frustum modules.
A
bstract
NEXT-100 is an electroluminescent high-pressure xenon gas time projection chamber that will search for the neutrinoless double beta (0
νββ
) decay of
136
Xe. The detector possesses two ...features of great value for 0
νββ
searches: energy resolution better than 1% FWHM at the
Q
value of
136
Xe and track reconstruction for the discrimination of signal and background events. This combination results in excellent sensitivity, as discussed in this paper. Material-screening measurements and a detailed Monte Carlo detector simulation predict a background rate for NEXT-100 of at most 4 × 10
−4
counts keV
−1
kg
−1
yr
−1
. Accordingly, the detector will reach a sensitivity to the 0
νββ
-decay half-life of 2.8 × 10
25
years (90% CL) for an exposure of 100 kg·year, or 6.0 × 10
25
years after a run of 3 effective years.
A new method to tag the barium daughter in the double-beta decay of ^{136}Xe is reported. Using the technique of single molecule fluorescent imaging (SMFI), individual barium dication (Ba^{++}) ...resolution at a transparent scanning surface is demonstrated. A single-step photobleach confirms the single ion interpretation. Individual ions are localized with superresolution (∼2 nm), and detected with a statistical significance of 12.9σ over backgrounds. This lays the foundation for a new and potentially background-free neutrinoless double-beta decay technology, based on SMFI coupled to high pressure xenon gas time projection chambers.
•A new design is proposed for deployable structures with bundle modules, using reciprocal linkages at the ends of the bars.•Reciprocal linkages reduce deformations in expandable beam ...structures.•Reciprocal linkages reduce the bending moments on the bars allowing for smaller sections.•The use of reciprocal linkages makes the eccentricities at all three nodes nearly equal.•The use of reciprocal linkages avoids the use of broken bars.•Calculations consider eccentricities and embedment in end linkages.•The experimental results show good accuracy with those calculated with the proposed method.
Deployable structures are an ideal solution for emergency buildings because of their lightness and compactness, allowing them to be transported to wherever they are needed. Generally the most frequent solutions use Scissor-like-Elements (SLE), but in this case the use of bundle modules is proposed. These systems were developed by Pérez Piñero, but have hardly been used since then. The article analyses the problems they present, as well as their advantages in reducing the number of bars and linkages required, which allows for the design of simpler and more economical structures. The geometrical and mechanical conditions of the linkages for triangular and square modules are analysed, as well as the typologies that may arise. A calculation method is also developed to analyse this type of structure. Finally, the performance of a flat grid is analysed in an analytical and experimental way using reciprocal links at its ends. Both theoretical calculations and experimental tests allow us to demonstrate the viability and efficiency of this new type of structure.
A
bstract
The NEXT experiment aims at the sensitive search of the neutrinoless double beta decay in
136
Xe, using high-pressure gas electroluminescent time projection chambers. The NEXT-White ...detector is the first radiopure demonstrator of this technology, operated in the Laboratorio Subterráneo de Canfranc. Achieving an energy resolution of 1% FWHM at 2.6 MeV and further background rejection by means of the topology of the reconstructed tracks, NEXT-White has been exploited beyond its original goals in order to perform a neu- trinoless double beta decay search. The analysis considers the combination of 271.6 days of
136
Xe-enriched data and 208.9 days of
136
Xe-depleted data. A detailed background modeling and measurement has been developed, ensuring the time stability of the radiogenic and cosmogenic contributions across both data samples. Limits to the neutrinoless mode are obtained in two alternative analyses: a background-model-dependent approach and a novel direct background-subtraction technique, offering results with small dependence on the background model assumptions. With a fiducial mass of only 3.50 ± 0.01 kg of
136
Xe-enriched xenon, 90% C.L. lower limits to the neutrinoless double beta decay are found in the
T
1
/
2
0
ν
> 5
.
5
×
10
23
−
1
.
3
×
10
24
yr range, depending on the method. The presented techniques stand as a proof-of-concept for the searches to be implemented with larger NEXT detectors.
Noble element time projection chambers are a leading technology for rare event detection in physics, such as for dark matter and neutrinoless double beta decay searches. Time projection chambers ...typically assign event position in the drift direction using the relative timing of prompt scintillation and delayed charge collection signals, allowing for reconstruction of an absolute position in the drift direction. In this paper, alternate methods for assigning event drift distance via quantification of electron diffusion in a pure high pressure xenon gas time projection chamber are explored. Data from the NEXT-White detector demonstrate the ability to achieve good position assignment accuracy for both high- and low-energy events. Using point-like energy deposits from
83
m
Kr calibration electron captures (
E
∼
45
keV), the position of origin of low-energy events is determined to 2 cm precision with bias
<
1
mm. A convolutional neural network approach is then used to quantify diffusion for longer tracks (
E
≥
1.5
MeV), from radiogenic electrons, yielding a precision of 3 cm on the event barycenter. The precision achieved with these methods indicates the feasibility energy calibrations of better than 1% FWHM at Q
β
β
in pure xenon, as well as the potential for event fiducialization in large future detectors using an alternate method that does not rely on primary scintillation.
Bias deployable grids are meshes with two directions of rotation on the ground plan with respect to the edges. They offer benefits such as three-dimensional resistance with supports around the entire ...perimeter of a rectangular layout, and consist exclusively of load-bearing scissors as opposed to the usual combinations of load-bearing scissors and bracing scissors. However, their resistance to angular distortion is limited, and they require auxiliary elements to maintain the fully deployed position. Nevertheless, they are very promising solutions for medium-span emergency buildings.
This paper proposes a bistable module adapted to bias deployable structures. The geometrical incompatibilities of several modules are analysed together with their behaviour based on the kinematic models that were built, which alternate different types of nodes and different geometries of the perimeter scissors, making it possible to calibrate the level of incompatibility introduced. The dimensions of the nodes are also taken into account. The tests are checked against the results of several series of dynamic calculations.
La atención a la evacuación del agua de lluvia y a la protección de la estructura ante los agentes meteorológicos ha dado lugar a un conjunto de propuestas de estructuras desplegables de aspas sobre ...planta rectangular en las que estas estructuras definen limas y faldones de pendiente suficiente. El trabajo parte de la resolución del trazado de estructuras desplegables de aspas planas simétricas y base cuadrangular con directriz quebrada, garantizándose el correcto funcionamiento cinemático mediante la construcción de modelos. Se estudian desplegables con directrices poligonales, curvas compuestas y también combinaciones de curvas y rectas. Se repasan los problemas de estabilización de la solución en el estado desplegado, incorporando la cobertura textil y cables de arriostramiento. Finalmente se desarrollan y analizan geométrica y cinemáticamente una serie de propuestas con superficies de intradós y extradós diferentes y otro grupo de ellas en las que los sentidos de despliegue no siguen los ejes del recinto a cubrir.
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