arXiv subjects

Yanina Biondi

Publications and source records attributed to Yanina Biondi.

3 recordsLinked to original sources

arXiv2026

MOTION, a liquid xenon time projection chamber platform for high voltage technologies in dark matter detectors

The XLZD observatory is a next-generation experiment designed to search for weakly interacting massive particles (WIMPs) and other rare events using a 60-80 tonne liquid xenon time projection chamber (TPC). This detector aims to achieve sensitivity across the full WIMP parameter space down to the neutrino fog, establishing the ultimate sensitivity for this dark matter search paradigm. This unprecedented scale introduces substantial engineering challenges and pushes operation into largely unexplored regimes: the interplay between high-voltage (HV) systems, liquid xenon, and conducting materials in ultra-pure environments. To systematically investigate these challenges, we have built MOTION, a 70 kg LXe detector dedicated to understanding HV performance and electrostatic phenomena up to 200 kV (negative polarity). We describe the design and construction of the experimental infrastructure, including the cryogenic system, xenon purification and storage. MOTION enables controlled studies of dielectric breakdown in LXe, permitting systematic characterization of discharge mechanisms and their dependence on electrode geometry, surface condition, and applied voltage. The detector also facilitates investigations of field emission and photoemission from electrodes following various surface treatments, and provides a platform for validating the design of an HV feedthrough constructed from radiopure materials. The insights from these studies are essential for ensuring the operational stability, radiopurity, and scalability required for next-generation dark matter detectors.

physics.ins-det↗

arXiv2025

Sterile-neutrino search based on 259 days of KATRIN data

Neutrinos are the most abundant fundamental matter particles in the Universe and play a crucial role in particle physics and cosmology. Neutrino oscillation, discovered about 25 years ago, reveals that the three known species mix with each other. Anomalous results from reactor and radioactive-source experiments suggest a possible fourth neutrino state, the sterile neutrino, which does not interact via the weak force. The KATRIN experiment, primarily designed to measure the neutrino mass via tritium $β$-decay, also searches for sterile neutrinos suggested by these anomalies. A sterile-neutrino signal would appear as a distortion in the $β$-decay energy spectrum, characterized by a discontinuity in curvature (kink) related to the sterile-neutrino mass. This signature, which depends only on the shape of the spectrum rather than its absolute normalization, offers a robust, complementary approach to reactor experiments. KATRIN examined the energy spectrum of 36 million tritium $β$-decay electrons recorded in 259 measurement days within the last 40 electronvolt below the endpoint. The results exclude a substantial part of the parameter space suggested by the gallium anomaly and challenge the Neutrino-4 claim. Together with other neutrino-disappearance experiments, KATRIN probes sterile-to-active mass splittings from a fraction of an electron-volt squared to several hundred electron-volts squared, excluding light sterile neutrinos with mixing angles above a few percent.

hep-ex↗

arXiv2017

A Dual-phase Xenon TPC for Scintillation and Ionisation Yield Measurements in Liquid Xenon

A small-scale, two-phase (liquid/gas) xenon time projection chamber (Xurich II) was designed, constructed and is under operation at the University of Zurich. Its main purpose is to investigate the microphysics of particle interactions in liquid xenon at energies below 50 keV, which are relevant for rare event searches using xenon as target material. Here we describe in detail the detector, its associated infrastructure, and the signal identification algorithm developed for processing and analysing the data. We present the first characterisation of the new instrument with calibration data from an internal 83m-Kr source. The zero-field light yield is 15.0 and 14.0 photoelectrons/keV at 9.4 keV and 32.1 keV, respectively, and the corresponding values at an electron drift field of 1 kV/cm are 10.8 and 7.9 photoelectrons/keV. The charge yields at these energies are 28 and 31 electrons/keV, with the proportional scintillation yield of 24 photoelectrons per one electron extracted into the gas phase, and an electron lifetime of 200 $μ$s. The relative energy resolution, $σ/E$, is 11.9 % and 5.8 % at 9.4 keV and 32.1 keV, respectively using a linear combination of the scintillation and ionisation signals. We conclude with measurements of the electron drift velocity at various electric fields, and compare these to literature values.

astro-ph.IM↗