γ -ray spectroscopy of 209Tl

States in ²⁰⁹Tl were populated using a multinucleon transfer reaction with a ¹³⁶Xe beam impinging on a thick ²⁰⁸Pb target at E =785 MeV. The beam was pulsed at 825-ns intervals in order to perform isomer decay spectroscopy. The known J^π=17 /2⁺ isomer in ²⁰⁹Tl was located at 1228(4) keV and measured to have a half-life of T_{1 /2}=146 (10 ) ns. A second isomer with J^π=13 /2⁺ was found to have T_{1 /2}=14 (5 ) ns. The previously suggested low-energy X and Y transitions were found to have energies 57(2) and 47(2) keV respectively, while the measurement of conversion coefficients and a new decay path make the spin assignments below the isomers experimentally firm. Correlating the delayed γ transitions with the prompt beam flash allowed the decay of states above the isomer to be found. The longer-lived isomer represents full alignment of the simplest two-particle, one-hole configuration and illuminates the remarkably weak coupling of the proton hole to the ²¹⁰Pb core.