Results of a search for daily and annual variations of the Po-214 half-life at the two year observation period

The brief description of installation TAU-2 intended for long-term monitoring of the half-life value \(\tau\) (\(\tau_{1/2}\)) of the \(^{214}\)Po is presented. The methods of measurement and processing of collected data are reported. The results of analysis of time series values \(\tau\) with different time step are presented. Total of measurement time was equal to 590 days. Averaged value of the \(^{214}\)Po half-life was obtained \(\tau=163.46\pm0.04\) \(\mu\)s. The annual variation with an amplitude \(A=(8.9\pm2.3)\cdot10^{-4}\), solar-daily variation with an amplitude \(A_{So}=(7.5\pm1.2)\cdot10^{-4}\), lunar-daily variation with an amplitude \(A_L=(6.9\pm2.0)\cdot10^{-4}\) and sidereal-daily variation with an amplitude \(A_S=(7.2\pm1.2)\cdot10^{-4}\) were found in a series of \(\tau\) values. The maximal values of amplitude are observed at the moments when the projections of the installation Earth location velocity vectors toward the source of possible variation achieve its maximal magnitudes.