Wednesday, 4 November 2026: 3 new papers, 0 cross-lists and 3 replacements in Instrumentation and Detectors (physics.ins-det), in arXiv's order, with full abstracts. The same papers as arXiv's own listing, set as a newspaper; every title links to arXiv.
Piezoelectric bending actuators provide deflections of several hundred micrometers and are used in electrical and mechanical engineering, acoustics, automation, automotive technology and healthcare. Highly efficient, low-cost piezoceramics offer a wide range of technical solutions. Their highpiezoelectric coefficients enable large strains at low electric field strengths. However, hysteresis, drift and creep impair positioning accuracy. Precise switching and positioning require compensation for these material-related effects, as well as varying mechanical loads and vibrations. A non-contact inductive proximity sensor is therefore combined with high-precision electronic circuit. Within a closed-loop control system, this sensor-actuator arrangement detects disturbances and enables their compensation, allowing highly efficient piezoceramics to be used for high-accuracy positioning. This paper investigates the electrodynamics of a specially developed eddy-current-based proximity sensor suitable for integration into confined spaces. A theoretical description explains its physical operating principle and enables analytical determination of the relative change in inductance as a function of actuator tip deflection. Experimental measurements validate the electrodynamic approach. The paper also considers energy harvesting applications. Measuring tip deflection allows the power dissipated in the piezoelectric transducer to be determined. The sensor system thus provides a basis for investigating and evaluating the performance of piezoelectric energy harvesters.
Project 8, a neutrino mass experiment, employs the novel frequency technique of cyclotron radiation emission spectroscopy (CRES) to perform a model independent measurement of neutrino mass via tritium beta decay. Our pioneering experiment will consist of a beamline that dissociates molecular tritium, surface cools atoms through accommodation, evaporatively cools and slows atoms, and traps them in a CRES resonant cavity to advance towards our sensitivity goal of 40 meV/c^2 for our final electron-weighted neutrino mass measurement. We are prototyping an electron cyclotron resonance (ECR) dissociator that uses a tunable 1 kW 2.45 GHz RF generator and electromagnets to ignite a hydrogen plasma in an aluminum resonant cavity. Our ECR source is designed to produce a high atom flux (~10^19 atoms/second) near room temperature. We present the engineering development, gas diagnostics, and spectroscopy data from our hydrogen plasma.
We present an in-situ azimuthal rotation stage for small-angle neutron scattering measurements. The stage provides an azimuthal rotation range of $315^\circ$ about the stage normal. At the reference sample-stick orientation, the stage normal is parallel to the incident neutron beam, so that the sample rotates in the plane perpendicular to the beam. Combined with a sample stick rotation about a second, orthogonal axis, the stage provides control of the magnetic-field direction relative to the crystal axes, while the field remains fixed in the laboratory frame. For a 5 mm diameter incident beam, sample-stick rotations of approximately $\pm315^\circ$ are accessible with negligible additional attenuation from the holder. The commercial rotator is specified for operation between 1 and 373 K and in magnetic fields up to 35 T, making the stage nominally compatible with the full temperature (1.8 to 320 K) and field (0 to 6.8 T) ranges of the used cryomagnet. As a working example, we characterize its performance on a spherical single crystal of MnSi between 20 and 35 K and in fields up to 183 mT, observing local sample heating during operation of $\sim$20 mK per $5^\circ$ step. We illustrate the design considerations behind the holder construction, with specific notes for mounting spherical samples, and discuss the resulting performance and limitations.