ONLINE EXPERIMENTS WITH CYCLOTRON PRODUCED SHORT-LIVED HAFNIUM ISOTOPES AS A TEST FOR STUDIES OF ION-EXCHANGE EQUILIBRIA OF ELEMENT-104 BY A CONTINUOUS CHROMATOGRAPHY TECHNIQUE

Short-lived (a few minutes) Hf isotopes recoiling from a target bombar ded with heavy ions were continuously, on-line transported by an aeros ol jet to the chemical equipment. The particulates were dissolved in d iluted HF + HNO3 and fed onto a system tem of ion exchange columns. A cationic filter removed from the solution any lanthanides, an anionic column served for chromatography of Hf fluoride complexes, another cat ionic column (filter) absorbed lanthanide isotopes formed in the decay of Hf nuclei during the elution time, and still one cation exchange c olumn isolated the daughter lanthanides from the collected eluate afte r necessary aging. The activity ratio of the two ''daughter'' fraction s was used to evaluate the elution time, and, finally, the distributio n coefficient. The data agreed with those obtained by traditional batc h and elution chromatography techniques. Also the charge of the comple x ion could be determined by measurements of the distribution coeffici ent versus the counterion concentration. The approach is prospective f or studying transactinides.