arXiv subjects

Ioannis Katsioulas

Publications and source records attributed to Ioannis Katsioulas.

3 recordsLinked to original sources

arXiv2022

Ionisation quenching factors from W-values in pure gases for rare event searches

The effect of ionisation quenching for ions is critical for experiments relying on the measurement of low energy recoils, such as direct Dark Matter searches. We present ionisation quenching factor estimates over a range of energies for protons, $α$-particles, and heavier ions in H$_{2}$, CH$_{4}$, N$_{2}$, Ar, CO$_{2}$, and C$_{3}$H$_{8}$ gases, estimated from the respective reference W-value measurements. The resulting ionisation quenching factors are compared with predictions from SRIM.

hep-ex↗

arXiv2020

Recent advancements of the NEWS-G experiment

NEWS-G (New Experiments With Spheres-Gas) is an experiment aiming to shine a light on the dark matter conundrum with a novel gaseous detector, the spherical proportional counter. It uses light gases, such as hydrogen, helium, and neon, as targets to expand dark matter searches to the sub-GeV/c$^{2}$ mass region. NEWS-G produced its first results with a 60 cm in diameter detector installed at LSM (France), excluding at 90% C.L. cross-sections above $4.4\cdot{10}^{37}$ cm$^{2}$ for dark matter candidates of 0.5 GeV/c$^{2}$ mass. Currently, a 140 cm in diameter detector is being built at LSM and a commissioning run is underway, prior to its installation at SNOLAB (Canada) at the end of the year. Presented here are developments incorporated in this new detector: a) sensor technologies using resistive materials and multi-anode read-out that allow high gain and high pressure operation; b) gas purification techniques to remove contaminants (H$_{2}$O, O$_{2}$); c) reduction of ${}^{210}$Pb induced background through copper electroforming methods; d) utilisation of UV-lasers for detector calibration, detector response monitoring and estimation of gas related fundamental properties. This next phase of NEWS-G will allow searches for low mass dark matter with unprecedented sensitivity.

physics.ins-det↗

arXiv2018

NEWS-G, Light dark matter search with a Spherical Proportional Counter, First results and Future prospects

NEWS-G (New Experiments With Spheres-Gas) is an experiment aiming to shine a light on the dark matter conundrum using a novel gaseous detector, the Spherical Proportional Counter. NEWS-G uses light noble gases, such as hydrogen, helium, and neon, as targets, to search for light dark matter down to the sub-GeV/c${}^{2}$ mass region. The first detector of NEWS-G, is a 60 cm diameter sphere already operated in the Underground Laboratory of Modane, while the full-scale detector, 140 cm in diameter, will be installed in SNOLab at the end of this year. In this work, we present the first NEWS-G results with neon as target, which excludes at 90$\%$ confidence level cross-sections above $4.4\cdot 10{}^{37}$ cm${}^{2}$ for a candidate with a mass 0.5 GeV$/$c${}^{2}$ based on 9.7 kg$\cdot$days of exposure. The status of the project and prospects for the future are also discussed.

hep-ex↗