Isotope 223U synthesized and identified[1;2].αenergy of 8 780(40)keV and a half-life of 55(10)μs.Theαenergy was calculated by subtracting knownαenergy of 219Th from measured decay sum energy of 223U and its daughter 219Th.Based on the advanced digital pulse processing technique,a new measurement forα-particle energy and half-life of 223U was performed at the gas-filled recoil separator,Spectrometer for Heavy Atoms and Nuclear Structure(SHANS).The isotope 223U was produced in the fusion-evaporation reaction 187Re(40Ar,p3n)223U.