Evidence for the formation of sodium hassate(VIII)

Hassium, element 108, was produced in the fusion reaction between 26Mg and 248Cm. The hassium recoils were oxidized in-situ to a highly volatile oxide, presumably HsO4, and were transported in a mixture of He and O2 to a deposition and detection system. The latter consisted of 16 silicon PIN-photodiodes facing a layer of NaOH, which served, in the presence of a certain partial pressure of water in the transport gas, as reactive surface for the deposition of the volatile tetroxides. Six correlated α-decay chains of Hs were detected in the first 5 detectors centred around detection position 3. In analogy to OsO4, which forms Na2[OsO4(OH)2], an osmate(VIII), with aqueous NaOH, HsO4 presumably was deposited as Na2[HsO4(OH)2], a hassate(VIII). (orig.)