Long term measurement of the $$^{222}$$ Rn concentration in the Canfranc Underground Laboratory
J. Amaré (Centro de Astropartículas y Física de Altas Energías (CAPA), Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, 50009, Spain, Laboratorio Subterráneo de Canfranc, Paseo de los Ayerbe s/n, Canfranc Estación, Huesca, 22880, Spain); I. Bandac (Laboratorio Subterráneo de Canfranc, Paseo de los Ayerbe s/n, Canfranc Estación, Huesca, 22880, Spain); A. Blancas (Centro de Astropartículas y Física de Altas Energías (CAPA), Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, 50009, Spain); S. Borjabad (Laboratorio Subterráneo de Canfranc, Paseo de los Ayerbe s/n, Canfranc Estación, Huesca, 22880, Spain); S. Buisán (AEMET, Delegación Territorial de AEMET en Aragón, Paseo del Canal 17, Zaragoza, 50007, Spain); et al - Show all 20 authors
We report the results of 6 years (2013–2018) of measurements of $$^{222}$$ Rn air concentration, relative humidity, atmospheric pressure and temperature in the halls A, B and C of the Canfranc Underground Laboratory (LSC). We have calculated all the Pearson correlation coefficients among these parameters and we have found a positive correlation between the $$^{222}$$ Rn concentration and the relative humidity. Both correlated variables show a seasonal periodicity. The joint analysis of laboratory data and 4 years (2015–2018) of the meteorological variables outside the laboratory shows the correlation between the $$^{222}$$ Rn concentration and the outside temperature. The collected information stresses the relevance of designing good Rn-mitigation strategies in current and future experiments at LSC; in particular, we have checked for two years (2017–2018) the good performance of the mitigation procedure of the ANAIS-112 experiment. Finally, we have monitored (2019–2021) for 2 years of live time, the radon-free air provided by the radon abatement system installed in the laboratory.