Investigation on the Variation of Radon Concentration in the ARGO-YBJ Experiment Hall
Using the Lomb-Scargle period grams and temporal variation folded into one period for statistical analysis, the radon concentration in the ARGO-YBJ experiment hall from Aug. 2009 through Apr. 2011 was investigated. Our results show that the radon concentration has main periods of half-day and 1-day with the period of 1 day being dominant. In one day the radon concentration reaches its peak at 11:20(Beijing Time)and reaches the minimum at 23:20(Beijing Time). In one year, the radon concentration is lower in June, the monthly variation amplitudes and initial phases folded into one day are various. These results are of importance to the study of variation of radon concentration and theoretical models, and provide a good chance to estimate the living environment in Tibet.