Electric quadrupole moments of high-spin isomers in ²⁰⁹Po and ²¹⁰Po

High-spin ^{209, 210}Po isomers were recoil-implanted into tetragonal tin and the electric quadrupole coupling constants have been measured with the TDPAC technique. Using a calculated value for the quadrupole moment of Q[²¹⁰Po(8⁺)] = - 57 fm² as standard for the electric field gradient calibration, the following other values are derived: Q[²⁰⁹Po( case17 2^-)] = -39(8) fm², Q[²¹⁰Po(11^-)] = -82(19) fm² and Q[²¹⁰Po(13^-) = -62(11) fm². These values are in agreement with the known structure of the isomers. The existence of more than one isomer in each isotope requires a data analysis procedure which takes into account feeding through all levels perturbed by the quadrupole interaction. A two-level formalism was developed and employed.