A new compact linear proton accelerator project (named LINAC 7) for multiple low-current applications, designed and built in-house at the Beam Laboratory of the University of the Basque Country (UPV/EHU) is described. The project combines the University, a research technology center and a private company with the aim of designing and building a compact, low-current proton accelerator capable of accelerating particles up to 7 MeV. In this paper, we present an overview of the accelerator design, summarize the progress and testing of the components that have been built, and describe the components that are being designed that will allow us to achieve the final desired energy of 7 MeV.

This paper presents a novel approach to the reconstruction of narrowband signals using undersampling techniques. Traditional sampling methods, which adhere to the Nyquist theorem, often require high sampling rates, leading to increased costs and data processing demands. In contrast, undersampling techniques can significantly reduce these requirements by sampling at rates lower than the Nyquist frequency. This work leverages the principles of compressive sensing to reconstruct frequency-sparse signals by sampling them at multiple distinct frequencies. The proposed method ensures accurate signal reconstruction by using Alias Prediction Diagrams (APDs) and their generalized form, Widened APDs (WAPDs), to predict the positions of aliases generated during the sampling process. The criteria for selecting appropriate sampling frequencies are derived, ensuring that the original signal can be accurately reconstructed even when composed of multiple narrowband components. The effectiveness of the proposed method is validated through experimental results obtained from a test bench capable of measuring signals up to 18GHz using sampling frequencies between 50MHz and 120MHz. The results demonstrate the successful reconstruction of signals with up to seven narrowband components, each with a bandwidth of around 150 kHz. Additionally, the proposed method offers significant reductions in acquisition, transmission, processing, and storage rates compared to direct sampling techniques; in the proposed setup these rates are reduced up to 1/300 of the direct sampling rates. This work provides a robust framework for efficient signal reconstruction in applications where reducing acquisition, processing and storage rates is crucial.

Magnetotactic bacteria (MTB) are aquatic microorganisms that biomineralize magnetic nanoparticles called magnetosomes, organizing them into chains that enable navigation along geomagnetic field lines. Their self‐propulsion, magnetic responsiveness, and preference for low‐oxygen environments make them promising candidates as biohybrid microrobots for biomedical and environmental applications. However, controlling large populations of MTB simultaneously remains a significant challenge. This study analyzes over 30 000 trajectories of Magnetospirillum gryphiswaldense (MSR‐1) under rotating magnetic fields (RMF) of varying strengths (0 − 1000 µT) and frequencies to characterize individual and collective motility behaviors. Trajectories shift from rectilinear to circular with increasing field strength, while collective alignment emerges above 250 µT. At 1000 µT and , up to 29.3% of bacteria align in the NorthSeeker (NS) direction and 23% in the South‐Seeker (SS) direction. Angular dispersion decreases from ≈ 38.2° to ≈14.7° with increasing field strength, whereas higher RMF frequencies significantly reduce alignment. Swimming velocity remains stable across most conditions, showing a robust bimodal distribution centered near 21.5 and 45 µm s ⁻¹ , with a deviation only under highest tested RMF condition. These findings reveal a collective dynamic dependent on the frequency and strength of the magnetic field and highlight that the individual response cannot be straightforwardly translated to collective dynamics.

This paper presents a cost-effective solution for high-frequency signal acquisition using a subsampling-based system. The focus is on the practical implementation of a uniform subsampling setup, leveraging Track-and-Hold Amplifiers (THAs) and precise timing control for efficient signal reconstruction. The system allows the acquisition of signals above the Nyquist frequency, significantly reducing data storage needs, simplifying real-time analysis, and enabling the use of economically competitive components. Special attention is given to the challenges and considerations in deploying such a system, including the need for synchronization between THAs and the measurement system, and the impact of timing jitter. The paper demonstrates that with careful implementation, subsampling-based systems offer a promising and economically viable approach for high-frequency signal acquisition and control.