arXiv subjects

Jose R. Navarro-Madrid

Publications and source records attributed to Jose R. Navarro-Madrid.

7 recordsLinked to original sources

arXiv2026

Resonant heterodyne conversion applied to a low-frequency haloscope for dark matter axion searches in the 1-35 MHz range

We study resonant heterodyne up-conversion in the RADES-BabyIAXO haloscope as a method to search for low-mass dark matter axions using microwave cavities. Starting from axion electrodynamics, we derive the axion-induced source term and the power extracted through a readout mode, explicitly accounting for the finite axion linewidth. This leads to effective quality factors that determine the pump-axion mixing, detection bandwidth, and detected signal power. We extend the BI-RME 3D full-wave formulation to heterodyne axion detection in a realistic two-port cavity, including pump leakage into the readout channel. Applying the formalism to the largest RADES-BabyIAXO cavity identifies the $\mathrm{quasi\textrm{-}TE}_{011}-\mathrm{quasi\textrm{-}TM}_{010}$ mode pair as a favorable configuration, enabling sensitivity to axion frequencies between 0.9 and 34.6 MHz. Analytical and full-wave predictions show excellent agreement at resonance, while the full-wave model provides a more accurate description off resonance and allows a precise characterization of the pump leakage. We also derive the optimal port couplings that maximize the scanning rate. Sensitivity projections for cryogenic copper and superconducting niobium cavities indicate that, under thermal-noise-limited conditions and assuming sufficient pump-leakage rejection, the experiment could probe axion-photon couplings down to $10^{-15}\,\mathrm{GeV}^{-1}$ at 90% confidence level, representing a significant improvement over previous heterodyne-based searches.

hep-ex↗

arXiv2026

A study of multicavity concept applied to hexagonal coaxial haloscopes

In this work, a study on the development of scalable multicavity architectures for axion haloscopes, based on a hexagonal coaxial geometry operating at $30$ GHz frequencies, is presented. To enhance the scanning rate and sensitivity within the limited volume of experimental magnet bores, the transition from a baseline single-cavity design to dual and triple-subcavity configurations is investigated. A novel tuning mechanism based on the rotation of one or two inner hexagonal prisms is implemented, providing a robust method to shift the resonant frequency while maintaining high form and quality factors. The results show that the triple-subcavity design achieves an improvement of $\times3$ over the single-cavity baseline. The scaling potential of quad-subcavity architectures under a strict radial constraint of $25$ mm is further explored. Theoretical analysis confirms that a four-subcavity system is feasible within a certain radial clearance, provided that wall thicknesses are strategically optimised to ensure frequency stability. The practical challenges associated with mode splitting, manufacturing tolerances, and thermal management in these high-order systems are also discussed. This one-port multicavity approach offers a viable path toward increasing the sensitive volume of haloscopes, enabling more efficient exploration of the axion dark matter parameter space in high-frequency regimes.

hep-ex↗

arXiv2025

Enhancement of dark-photon haloscope sensitivity with degenerate modes: toward axion-level form factor and polarization determination

The dark photon has been postulated as a potential constituent of dark matter, exhibiting notable similarities to the axion. The primary distinction between the two particles lies in the nature of their respective fields: the dark photon field is a vector field with a polarization direction that remains undetermined. This work explores the prospect of utilizing three degenerate modes for scanning the three dimensions of space in order to mitigate the low form factor expected in the detection of the dark photon due to their unknown polarization. The employment of an haloscope with three orthogonal and degenerate modes in conjunction with the coherent sum of signals is demonstrated in this work in order to enhance the dark photon form factor up to the axion form factor, and to determine the direction of the dark photon polarization vector. We show in this manuscript that the maximum form factor is achieved in cavities of cubic, spherical, and cylindrical geometries, considering the introduction of tuning elements. To achieve this adequately, some conditions reviewed in this article must be fulfilled in the resonant cavity, leading to uncertainties in the final measurement. Finally, this technique can allow the simultaneous search for dark matter axions and dark photons, and to the knowledge of the authors, the method shown in this work is the most effective one for detecting dark photon with microwave resonant cavities.

hep-ph↗

arXiv2025

Multiple-cavities interferometric analysis for dark matter axions directional-sensitive search based on signal cross-correlation processing

Current axion detection limits neglect the relevance of the relative velocity between the axion field and the detectors. However, this aspect can lead to a daily modulation of the detected axion signal. In this work, we calculate the cross-correlation of various signals potentially originated in multiple-cavity setups, and we analyze how the signal-to-noise ratio and directional sensitivity depend on the signal cross-correlation among multiple cavities. The signal-to-noise ratio after cross-correlation exhibits a greater rate of increase over time compared to the power-summation technique, making it clear that this method could be potentially employed in a real setup for the reduction of the exposure time. For the study of the daily modulation, three interferometric experiments have been proposed in this manuscript: (i) three rectangular cavities in different Earth locations; (ii) three rectangular cavities located in the same Earth spot but oriented towards different perpendicular directions; (iii) six rectangular cavities in the same Earth location but oriented towards different directions. In each set-up, we have simulated three different cavity lengths. Similar results have been found for the cases (i) and (ii): when the highest length upon the three proposed is considered, a phase difference between the recorded voltages of more than $2^{\circ}$ has been obtained with our numerical calculations. We observe a daily modulation in the imaginary part of the signals cross-correlation for experiment (iii), that could be potentially used for the characterization of the axion velocity distribution. To the knowledge of the authors, this is the first time that the cross-correlation technique has been applied to the directional sensitivity analysis of an array of haloscopes.

hep-ex↗

arXiv2024

Dark Matter Axion Detection with Neural Networks at Ultra-Low Signal-to-Noise Ratio

We present the first analysis of Dark Matter axion detection applying neural networks for the improvement of sensitivity. The main sources of thermal noise from a typical read-out chain are simulated, constituted by resonant and amplifier noises. With this purpose, an advanced modal method employed in electromagnetic modal analysis for the design of complex microwave circuits is applied. A feedforward neural network is used for a boolean decision (there is axion or only noise), and robust results are obtained: the neural network can improve by a factor of $5\cdot 10^{3}$ the integration time needed to reach a given signal to noise ratio. This could either significantly reduce measurement times or achieve better sensitivities with the same exposure durations.

hep-ex↗

arXiv2024

Microwave Technologies in Experiments for Detection of Dark Matter Axions

This article reviews different microwave technologies used in dark matter axion detection experiments with resonant cavities. The general concepts of the experiment are presented and ways to optimize the design parameters of microwave resonators are discussed. Additionally, different frequency tuning systems are described. Finally, research lines where microwave engineering can contribute to this kind of axion detection are presented.

physics.ins-det↗

arXiv2022

The Canfranc Axion Detection Experiment (CADEx): Search for axions at 90 GHz with Kinetic Inductance Detectors

We propose a novel experiment, the Canfranc Axion Detection Experiment (CADEx), to probe dark matter axions with masses in the range 330-460 $μ$eV, within the W-band (80-110 GHz), an unexplored parameter space in the well-motivated dark matter window of Quantum ChromoDynamics (QCD) axions. The experimental design consists of a microwave resonant cavity haloscope in a high static magnetic field coupled to a highly sensitive detecting system based on Kinetic Inductance Detectors via optimized quasi-optics (horns and mirrors). The experiment is in preparation and will be installed in the dilution refrigerator of the Canfranc Underground Laboratory. Sensitivity forecasts for axion detection with CADEx, together with the potential of the experiment to search for dark photons, are presented.

hep-ex↗