A
bstract
RADES (Relic Axion Detector Exploratory Setup) is a project with the goal of directly searching for axion dark matter above the 30
μ
eV scale employing custom-made microwave filters in ...magnetic dipole fields. Currently RADES is taking data at the LHC dipole of the CAST experiment. In the long term, the RADES cavities are envisioned to take data in the BabyIAXO magnet. In this article we report on the modelling, building and characterisation of an optimised microwave-filter design with alternating irises that exploits maximal coupling to axions while being scalable in length without suffering from mode-mixing. We develop the mathematical formalism and theoretical study which justifies the performance of the chosen design. We also point towards the applicability of this formalism to optimise the MADMAX dielectric haloscopes.
INTRODUCTIONNon-pharmacological treatments help control tension-type headache; however, evidence about their effectiveness is still limited. This study evaluates the effectiveness of physical therapy ...based on cervical spine kinesiotherapy and posture correction exercises compared to a programme of relaxation techniques only (Schultz's Autogenic Training, AT). METHODSTension-type headache is very common among university students. We randomly selected 152 university students with a diagnosis of tension-type headache according to the criteria of the International Headache Society. Eighty-four were women (55.3%) and 68 were men (44.7%). Mean age was 20.42±2.36 years. The study design is a randomised controlled trial of a non-pharmacological intervention with a blinded evaluation of response variables. We compared the results of two independent samples: AT was used in one of the groups while the other group received AT plus cervical spine kinesiotherapy and posture correction training. Patients recorded any changes in the parameters of pain (frequency, intensity, and duration) and drug consumption in a headache diary before treatment, at 4 weeks, and at 3 months. RESULTSBoth interventions achieved a decrease in all the parameters of pain; however, decreases in frequency and intensity were more significant in the combined treatment group (P<0.01) (d=0.4). CONCLUSIONSSuch active, non-invasive therapies as AT and cervical spine kinesiotherapy, and especially the combination of both, effectively reduce tension-type headache by preventing and managing the potential psychophysical causes of this disorder. Future research should aim to assess the long-term effects of these interventions.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Tuning is an essential requirement for the search of dark matter axions employing haloscopes since its mass is not known yet to the scientific community. At the present day, most haloscope tuning ...systems are based on mechanical devices which can lead to failures due to the complexity of the environment in which they are used. However, the electronic tuning making use of ferroelectric materials can provide a path that is less vulnerable to mechanical failures and thus complements and expands current tuning systems. In this work, we present and design a novel technique for using the ferroelectric Potassium Tantalate (KTaO3 or KTO) material as a tuning element in haloscopes based on coupled microwave cavities. In this line, the structures used in the Relic Axion Detector Exploratory Setup (RADES) group are based on several cavities that are connected by metallic irises, which act as interresonator coupling elements. In this article, we also show how to use these KTaO3 films as interresonator couplings between cavities, instead of inductive or capacitive metallic windows used in the past. These two techniques represent a crucial upgrade over the current systems employed in the dark matter axions community, achieving a tuning range of 2.23% which represents a major improvement as compared to previous works (< 0.1%) for the same class of tuning systems. The theoretical and simulated results shown in this work demonstrate the interest of the novel techniques proposed for the incorporation of this kind of ferroelectric media in multicavity resonant haloscopes in the search for dark matter axions.
A
bstract
We present results of the Relic Axion Dark-Matter Exploratory Setup (RADES), a detector which is part of the CERN Axion Solar Telescope (CAST), searching for axion dark matter in the 34.67
...μ
eV mass range. A radio frequency cavity consisting of 5 sub-cavities coupled by inductive irises took physics data inside the CAST dipole magnet for the first time using this filter-like haloscope geometry. An exclusion limit with a 95% credibility level on the axion-photon coupling constant of g
aγ
≳ 4 × 10
−
13
GeV
−
1
over a mass range of 34
.
6738
μ
eV
< m
a
<
34
.
6771
μ
eV is set. This constitutes a significant improvement over the current strongest limit set by CAST at this mass and is at the same time one of the most sensitive direct searches for an axion dark matter candidate above the mass of 25
μ
eV. The results also demonstrate the feasibility of exploring a wider mass range around the value probed by CAST-RADES in this work using similar coherent resonant cavities.
Resumen Introducción Los tratamientos no farmacológicos consiguen controlar la cefalea tensional, sin embargo, la evidencia es todavía limitada. Esta investigación estudia la eficacia de una ...intervención fisioterápica, basada en cinesiterapia cervical y pautas de higiene postural, que pretende mejorar los resultados obtenidos únicamente con técnicas de relajación (Entrenamiento Autógeno de Schultz EA). Métodos Se seleccionó a 152 estudiantes universitarios (sector poblacional entre quienes esta patología es muy frecuente), 84 mujeres (55,3%) y 68 hombres (44,7%), con edad media de 20,42 años (DT = 2,36), diagnosticados de cefalea tensional, según criterios de la International Headache Society. Se diseñó un ensayo clínico, no farmacológico, controlado y aleatorizado, con evaluación ciega de las variables respuesta. Se compararon los resultados de 2 muestras paralelas e independientes, aplicando a una el EA y a la otra la combinación de este con un programa de cinesiterapia cervical y educación postural. Se cuantificaron la mejoría en los parámetros dolorosos (frecuencia, intensidad y duración) y la reducción del consumo de fármacos, en diarios de cefaleas, antes de los tratamientos y después, a las 4 semanas y a los 3 meses. Resultados Los 2 grupos de intervención evolucionaron positivamente, consiguiéndose una reducción más significativa en la frecuencia e intensidad de las cefaleas con el tratamiento combinado (p < 0,01) (d = 0,4). Conclusiones Las terapias activas, no invasivas, como el EA y la cinesiterapia cervical, y especialmente la combinación de ambos, consiguen reducir la cefalea tensional, al prevenir y controlar las posibles causas psicofísicas de este trastorno. Como futuras líneas de investigación, sería interesante evaluar el mantenimiento de los beneficios a largo plazo.
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Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A
bstract
Haloscopes are resonant cavities that serve as detectors of dark matter axions when they are immersed in a strong static magnetic field. In order to increase the volume and improve space ...compatibility with dipole or solenoid magnets for axion searches, various haloscope design techniques for rectangular geometries are discussed in this study. The volume limits of two types of haloscopes are explored: those based on single cavities and those based on multicavities. In both cases, possibilities for increasing the volume of long and/or tall structures are presented. For multicavities, 1D geometries are explored to optimise the space in the magnets. Also, 2D and 3D geometries are introduced as a first step in laying the foundations for the development of these kinds of topologies. The results prove the usefulness of the developed methods, evidencing the ample room for improvement in rectangular haloscope designs nowadays. A factor of three orders of magnitude improvement in volume compared with a single cavity based on the WR-90 standard waveguide is obtained with the design of a long and tall single cavity. Similar procedures have been applied for long and tall multicavities. Experimental measurements are shown for prototypes based on tall multicavities and 2D structures, demonstrating the feasibility of using these types of geometries to increase the volume of real haloscopes.
The electromagnetic coupling axion–photon in a microwave cavity is revisited with the Boundary Integral-Resonant Mode Expansion (BI-RME) 3D technique. Such full-wave modal technique has been applied ...for the rigorous analysis of the excitation of a microwave cavity with an axion field. In this scenario, the electromagnetic field generated by the axion–photon coupling can be assumed to be driven by equivalent electrical charge and current densities. These densities have been inserted in the general BI-RME 3D equations, which express the RF electromagnetic field existing within a cavity as an integral involving the Dyadic Green’s functions of the cavity (under Coulomb gauge) as well as such densities. This method is able to take into account any arbitrary spatial and temporal variation of both magnitude and phase of the axion field. Next, we have obtained a simple network driven by the axion current source, which represents the coupling between the axion field and the resonant modes of the cavity. With this approach, it is possible to calculate the extracted and dissipated RF power as a function of frequency along a broad band and without Cauchy–Lorentz approximations, obtaining the spectrum of the electromagnetic field generated in the cavity, and dealing with modes relatively close to the axion resonant mode. Moreover, with this technique we have a complete knowledge of the signal extracted from the cavity, not only in magnitude but also in phase. This can be an interesting issue for future analysis where the axion phase is an important parameter.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
We investigate unusual surface plasmons polariton (SPP) propagation and light-matter interactions in ultrathin black phosphorus (BP) films, a 2D material that exhibits exotic electrical and physical ...properties due to its extremely anisotropic crystal structure. Recently, it has been speculated that the ultra-confined surface plasmons supported by BP may present various topologies of wave propagation bands, ranging from anisotropic elliptic to hyperbolic, across the mid- and near-infrared regions of the electromagnetic spectrum. By carefully analyzing the natural nonlocal anisotropic optical conductivity of BP, derived using the Kubo formalism and an effective low-energy Hamiltonian, we demonstrate here that the SPP wavenumber cutoff imposed by nonlocality prohibits that they acquire an arbitrary hyperbolic topology, forcing operation in the canalization regime. The resulting nonlocality-induced canalization presents interesting properties, as it is inherently broadband, enables large light-matter interactions in the very near field, and allows extreme device miniaturization. We also determine fundamental bounds to the confinement of BP plasmons, which are significantly weaker than for graphene, thus allowing a larger local density of states. Our results confirm the potential of BP as a promising reconfigurable plasmonic platform, with exciting applications, such as planar hyperlenses, optoelectronic components, imaging, and communication systems.
A numerical method is proposed for the analysis of highly dispersive linear and non-linear metamaterial structures. Pulse propagation along non-linear composite right/left-handed (CRLH) transmission ...line (TL) is studied. The dispersive CRLH line is loaded with hyper-abrupt diodes to achieve non-linearity. The characteristic impedance and propagation constant of each unit-cell of the CRLH TL is varied at each time-step, and the nonuniform line is then analysed. A novel interpolation scheme, based on the smooth behaviour of the propagation constant with small variations of the shunt capacitor is proposed. The numerical results show that high accuracy and up to 80% reduction of the computational cost is achieved. The impulse-regime radiation of a leaky-wave antenna is analysed and used to describe a real-time spectrogram analyser (RTSA). A new calibration method for the system, which takes into account the directivity variation of the antenna with frequency, is proposed. This method provides an extremely fast and accurate tool to characterise the behaviour of leaky-wave-based RTSA systems.
Non-pharmacological treatments help control tension-type headache (TTH); however, evidence about their effectiveness is still limited. This study evaluates the effectiveness of physical therapy based ...on cervical spine kinesiotherapy and posture correction exercises compared to a programme of relaxation techniques only (Schultz's Autogenic Training, AT).
TTH is very common among university students. We randomly selected 152 university students with a diagnosis of TTH according to the criteria of the International Headache Society. Eighty-four were women (55.3%) and 68 were men (44.7%). Mean age was 20.42±2.36 years. The study design is a randomised controlled trial of a non-pharmacological intervention with a blinded evaluation of response variables. We compared the results of two independent samples: AT was used in one of the groups while the other group received AT plus cervical spine kinesiotherapy and posture correction training. Patients recorded any changes in the parameters of pain (frequency, intensity, and duration) and drug consumption in a headache diary before treatment, at 4 weeks, and at 3 months.
Both interventions achieved a decrease in all the parameters of pain; however, decreases in frequency and intensity were more significant in the combined treatment group (P<0.01) (d=0.4).
Such active, non-invasive therapies as AT and cervical spine kinesiotherapy, and especially the combination of both, effectively reduce TTH by preventing and managing the potential psychophysical causes of this disorder. Future research should aim to assess the long-term effects of these interventions.
Los tratamientos no farmacológicos consiguen controlar la cefalea tensional, sin embargo, la evidencia es todavía limitada. Esta investigación estudia la eficacia de una intervención fisioterápica, basada en cinesiterapia cervical y pautas de higiene postural, que pretende mejorar los resultados obtenidos únicamente con técnicas de relajación (Entrenamiento Autógeno de Schultz EA).
Se seleccionó a 152 estudiantes universitarios (sector poblacional entre quienes esta patología es muy frecuente), 84 mujeres (55,3%) y 68 hombres (44,7%), con edad media de 20,42 años (DT = 2,36), diagnosticados de cefalea tensional, según criterios de la International Headache Society. Se diseñó un ensayo clínico, no farmacológico, controlado y aleatorizado, con evaluación ciega de las variables respuesta. Se compararon los resultados de 2 muestras paralelas e independientes, aplicando a una el EA y a la otra la combinación de este con un programa de cinesiterapia cervical y educación postural. Se cuantificaron la mejoría en los parámetros dolorosos (frecuencia, intensidad y duración) y la reducción del consumo de fármacos, en diarios de cefaleas, antes de los tratamientos y después, a las 4 semanas y a los 3 meses.
Los 2 grupos de intervención evolucionaron positivamente, consiguiéndose una reducción más significativa en la frecuencia e intensidad de las cefaleas con el tratamiento combinado (p < 0,01) (d = 0,4).
Las terapias activas, no invasivas, como el EA y la cinesiterapia cervical, y especialmente la combinación de ambos, consiguen reducir la cefalea tensional, al prevenir y controlar las posibles causas psicofísicas de este trastorno. Como futuras líneas de investigación, sería interesante evaluar el mantenimiento de los beneficios a largo plazo.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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