Radiations ofRa227

${\mathrm{Ra}}^{227}$ has been prepared by the slow neutron irradiation of ${\mathrm{Ra}}^{226}$ in the NRX reactor. ${\mathrm{Ra}}^{227}$ is a ${\beta }^{-}$ emitter with a half-life of 41.2±0.2 minutes and with a ${\beta }^{-}$ end point of 1.31±0.02 Mev. Gamma rays of 291 and 498 kev were observed with a scintillation spectrometer. The cross section for the reaction ${\mathrm{Ra}}^{226}(n, \gamma ){\mathrm{Ra}}^{227}$ was found to be 23 barns.