The ionization yield in a methane-filled spherical proportional counter
Abstract
Spherical proportional counters (SPCs) are gaseous particle detectors sensitive to single ionization electrons in their target media, with large detector volumes and low background rates. The collaboration employs this technology to search for low-mass dark matter, having previously performed searches with detectors at the Laboratoire Souterrain de Modane (LSM), including a recent campaign with a 135 cm diameter SPC filled with methane. While in situ calibrations of the detector response were carried out at the LSM, measurements of the mean ionization yield and fluctuations of methane gas in SPCs were performed using a 30 cm diameter detector. The results of multiple measurements taken at different operating voltages are presented. A UV laser system was used to measure the mean gas gain of the SPC, along with and aluminum-fluorescence calibration sources. These measurements will inform the energy response model of future operating detectors.
Cite
@article{arxiv.2410.16350,
title = {The ionization yield in a methane-filled spherical proportional counter},
author = {M. M. Arora and L. Balogh and C. Beaufort and A. Brossard and M. Chapellier and J. Clarke and E. C. Corcoran and J. -M. Coquillat and A. Dastgheibi-Fard and Y. Deng and D. Durnford and C. Garrah and G. Gerbier and I. Giomataris and G. Giroux and P. Gorel and M. Gros and P. Gros and O. Guillaudin and E. W. Hoppe and I. Katsioulas and F. Kelly and P. Knights and P. Lautridou and A. Makowski and I. Manthos and R. D. Martin and J. Matthews and H. M. McCallum and H. Meadows and L. Millins and J. -F. Muraz and T. Neep and K. Nikolopoulos and N. Panchal and M. -C. Piro and N. Rowe and D. Santos and G. Savvidis and I. Savvidis and D. Spathara and F. Vazquez de Sola Fernandez and R. Ward},
journal= {arXiv preprint arXiv:2410.16350},
year = {2025}
}
Comments
11 pages, 8 figures